Guide

Light exposure is a big factor to consider when growing herbs in a desert environment. Plant tags may say a plant needs full sun, usually meaning 6-8 hours of full sunlight, but keep in mind those recommendations are for where the
plant was grown. “Full sun” in the herb books and plant tags, may translates to ½ sun – ½ shade or dappled sunshine during the summer months in Tucson. 

Some herbs, such as basil, and rosemary, are true sun lovers, but during the summer in the southwest the sun can be very intense, and temperatures can reach 105°. An eastern exposure is considered ideal, giving sun in the morning and shade in the afternoon. Other locations are quite acceptable if measures are taken to limit summer sun exposure by covering plants with 30-40% shade cloth or moving them to shadier parts of the yard. Dry hot winds can also be a problem. Taking advantage of a wall, fence, deciduous trees, or  edge will allow you to put your plants in the best location.

Winter sun and wind are not as harsh. Many herbs enjoy full sun in the winter but will need to be protected from the occasional frost. They can be covered if nighttime temperatures drop below 32°. Cold weather hardiness of herb plants and plants in general is dependent upon where you live in Tucson. The only way to find out if a particular plant will survive the winter is to try it. City location and garden placement on your property will give you some
indication whether tender perennials will make it or not. There are many herbs that will grow year-round in Tucson regardless of your location.

If you grow herb plants in pots and other containers, you can control their environment more closely. The pots can be moved in and out of the sun, wind, and cold, onto the patio or into the house temporarily to protect them from the elements.

Important things to consider when growing herbs are soil structure and most important drainage. Due to the heat and lack of rainfall, desert soils tend to be sandy, rocky, and lacking in organic material. Another common problem is caliche, soil that is cemented together by calcium carbonate. Caliche can impair water drainage, one of the most important factors to consider when growing herbs.

2The University of Arizona Cooperative Extension Soil Important things to consider when growing herbs are soil structure and most important drainage. Due to the heat and lack of rainfall, desert soils tend to be sandy, rocky, and lacking in organic material. Another common problem is caliche, soil that is cemented together by calcium carbonate. Caliche can impair water drainage, one of the most important factors to consider when growing herbs. There are things you can do to improve soil structure and drainage in your garden. Dig beds at least a foot deep. Adding 2-4 inches of compost into your garden bed will improve the structure, increase water holding capacity, add nutrients and increase the number of beneficial microorganisms. Addition of sand will improve drainage in clay soil. Caliche can in some cases be broken up. For more information about caliche, read Managing Caliche in the Home Yard.

Growing herbs in the ground can be hard work. Another option is to grow herbs in pots or raised beds. Remember that herbs like well-drained soil. Be sure to use a well- draining potting soil. You can create your own mix. Here is one suggestion:

• 1 parrt coco coir: holds water
• 1 part perilite: improves drainage and aerates soil
• 1 part vermiculite: improves soil and moisture retention
• 1 part coarse sand: improves drainage
• 1 part compost: adds nutrients

This is referred to as a soilless medium or soilless mix. If you purchase a commercially packaged mix you may have to add additional sand or perlite to get proper drainage. Dampen the mix and squeeze a handful, if it stays in a
clump when you open your hand it probably deeds more sand or perlite. It should just fall apart. A proper mix when watered heavily will be moist but will not stay soggy from too much organic material. You may have to experiment to get the right balance of ingredients (Young, 2016).

Growing herbs in pots has several benefits. Pots are perfect for small yards or patios. It doesn’t matter what kind of soil is in the yard. Containers can be filled with a rich free draining soil mix to fit the needs of each plant. In the summer pots can be moved to shadier spots and frost sensitive plants can be moved to a protected location in the winter.

When selecting containers there are several factors to consider. Some gardeners prefer plastic pots, others prefer clay pots.

• Plastic pots are lighter and more affordable; however, they can retain more water than clay pots and absorb heat especially black plastic pots. 
• Clay pots are porous letting water evaporate. This helps keep plant roots cooler in the summer. Plants in clay pots may require more water. Clay pot soil mix should contain a little more coco coir to help compensate.
• Wooden boxes and whiskey barrels also work very well.

Whatever the container, it must have drainage holes in the bottom. Raise pots up off the ground to allow water to drain and allow air to circulate. Plants will not survive if the soil does not drain well. 

Pots should be at least 14 inches in diameter. Larger pots give roots space to develop, protect the roots from extreme temperatures, and require less frequent watering than smaller pots. Containers in direct summer sun tend to “cook” the roots and any pot under 14” in size will be very difficult to keep moist. Large pots can be heavy and difficult to move. Consider putting larger pots on wheels.

All containers must be thoroughly clean when planted and should be soaked for a short time in a 10% bleach solution to sterilize them and kill any harmful organisms if they were used previously.

Water plants often enough to keep them moist but not soggy – proper soil drainage is the secret. In summer this may mean watering pots twice a day. If plants need water more than twice a day, then chances are the pot is getting too much sun or the plant is pot bound. Container placement will help to reduce the amount of water they need. If a reference source says a plant should have direct sun this may not be necessarily true for Tucson. The plant may grow well in partial shade and its water requirements will be much different.

For plants in the ground, it is better to water deeply and less often. Daily, shallow irrigation can stunt and kill plants in the ground. The garden can be watered manually by hose, drip irrigation, or soaker hose making sure the water soaks in at least 12 inches. As a rule, water should not be applied to the foliage because it can cause sunburn and the minerals in our water can cause leaf damage. If using drip irrigation, make sure emitters are strategically placed especially for herbs that increase by creeping along the soil surface such as thyme, prostrate rosemary, and catnip.

Garden soils for herbs can be prepared using the same recommendations for fertilizer as are used in vegetable planting. However, herbs do not need heavy or frequent application of fertilizer. Perennial herbs will benefit from the application of compost or organic amendments such as fish emulsion, bone meal and blood meal in the spring.

If a soilless potting mix is used, then the fertilizer requirements are different because this may be a sterile medium which contains no nutrients (check the package). Therefore, it will be necessary to fertilize your pots on a regular schedule – usually once a week. Use a balanced fertilizer that contain nitrogen, phosphorus, and potassium (NPK). There are many water-soluble plant foods on the market, and it is not critical which one is used but it must include all elements. A more convenient way to feed pots is to add a slow-release fertilizer to the soil mix that only needs to be applied every three months. Always make sure to follow package directions.

Insects, generally, do not bother herbs as often as they do most other plants. It is best not to use systemic insect controls on food plants. A few insects will not harm plants and many insects are predators and should not be killed under any circumstances. If there is a harmful infestation, insecticidal soap usually works very well. Make sure to follow the directions on the container. Leaf chewing caterpillars can be picked off by hand or controlled with a natural bacteria, Bacillus thuringiensis (Bt). It can be purchased in garden supply stores and is safe for all living things except caterpillars (National Pesticide Information Center).

Herbs can benefit other garden plants by attracting insects that feed on you garden pests. The green lacewing, for example, feeds on aphids, thrips, and other annoying soft-bodied insects. Flowers of dill, yarrow, and cilantro attract the green lacewing, as well as hoverflies, lady bugs, and parasitic wasps. When it flowers basil becomes a bee heaven.

Most herbs can be easily grown from seed. There are benefits of growing your own herb plants:

• Many seed companies sell a wide variety of interesting herb seeds. You can explore a whole range of herbs that you can’t get at the local nurseries.
• It is much more economical to grow plants from seed or to make cuttings and divisions of plants you already have. It can also be very rewarding to share your baby plants with other herb gardeners.
• When you propagate and grow your own plants, you have total control of the growing conditions. You choose the soil and fertilizer.

Fun Fact: You can use your Pima County Library card to checkout plant seeds.

Herbs respond well to being pinched or trimmed back. Pruning will encourage new and vigorous growth. Trimmings of culinary plants can be used fresh in the kitchen, frozen or dried for future use.

Harvesting can be done in all seasons, not just fall. Cut the stems or leaves in the early morning or evening as there are less oils present in the leaves during the heat of the day.

There are several ways to dry herbs:

• Dry in bunches upside down in a dark place (2 weeks) or on a screen covered with cheesecloth.
• Small bunches may be dried in a microwave oven. Lay the cleaned leaves in a single layer between two pieces of paper towel. Microwave them in 30-second sessions, turning the leaves over between each session. Repeat until the leaves are completely dry and brittle.
• Herbs can also be spread on a cookie sheet and dried on the “warm” setting in the oven.
• Large leaved herbs such as sage or basil should be stored whole and crumbled when used to retain peak flavor. Keep leaves whole for tea.

To reduce herbs to powder, put in blender. Store jars, plastic bags, or tins in a dark cupboard. Store up to a year then replace. In cooking, use 1/3 to 1/2 more fresh herbs than when using dry herbs (Herman, 2021).

In the desert southwest, herbs can be grouped into cool- season annuals, warm-season annuals, and perennials. Annuals live for one season and then die. Cool-season annuals grow from October to May, and warm-season annuals grow from April to November.

Perennial herbs live for several years, but some prefer the heat of summer while others can’t survive our hot dry summers.

Cool-season annual herb: Fall is the best time to plant cool-season annual herb. (see planting calendar) They prefer to grow in the cool to mild days and chilly to cold nights we have in Tucson during the cool season. Planting herbs in the fall when temperatures are cooler relieves them of heat stress and allows their roots to get well established. Just remember, not all cool season herbs are cold hardy. They will have to be protected if there is frost.

Cool-season annual herb transplants can also be put out in spring, but spring gardens require extra attention because of longer hotter days and strong drying winds. Your plants may dry out rapidly and a temporary protective wind screen may be necessary until the plants become established and mature. Plant the largest transplants you can find. Any plants lost in the spring can be replanted in the fall.

Warm-season annual herb: Spring is a good time to plant warm season herbs such as basil and summer savory. The temperatures are still cool enough to let the plants get established before summer heat sets in.

Cool-season perennial herb: Fall is a good time to start perennial herbs that prefer cooler weather such as French tarragon, lemon balm, marjoram, mint, oregano, and chamomile. Most perennial herbs can put up with some cold weather.

Warm-season perennial herb: Heat loving perennial herbs such as Mexican tarragon, lemon verbena, lemon grass and society garlic prefer to be set out in the spring. Planting in the spring gives herbs time to get established so they will be in a much stronger position to deal with summer heat. If you do any planting in the summer, watch your watering carefully. Plants in pots may need to be watered twice a day and almost all herbs prefer a little afternoon shade during the hottest part of the summer.

What to Plant

Herman, Marilyn and Sussanne Dreiessen (2021). Preserving Herbs by Freezing or Drying. University of Minnesota Extension.

Parlin, Jennifer, Parker Filer, Daniel McDonald, Jacqui Stork, and Jada Parker. (2021). Growing Herbs for the Health of It! Arizona.edu/pub/az1922-2021.pdf

National Pesticide Information Center, Oregon State University. http://npic.orst.edu/factsheets/btgen.html

Walworth, J and Kelly, J (2002). Managing Caliche in the Home Yard.arizona.edu/pub/az1281.pdf.

Young, K. (2016). Container gardening in the Southwest. arizona.edu/pubs/az1713-2016.pdf.

Gilmer, Maureen (2015). Growing Vegetables in Drought, Desert, & Dry Times. Sasquatch Books. Seattle, WA

Owens, Dave (2000). Extreme Gardening. Poco Verde Landscaping. Tempe, AZ

Soule, Jacqueline (2022). Southwest Fruit and Vegetable Gardening. Cool Springs Press. Beverly, MA

The Low Desert Herb Gardening Handbook. Available online from the Arizona Herb Association

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Witches broom symptoms on palo verde trees were first described over 50 years ago, but the cause of the disease was unknown until recently. Our research has shown that a previously unknown multi-segmented, single-stranded RNA plant virus, classified in the genus Emaravirus, infects palo verde trees. This plant virus associated with broom-affected palo verde trees is a new discovery and has been confirmed in blue palo verde, Mexican palo verde, and Foothills palo verde. The presence of the palo verde broom virus also has been confirmed by molecular detection methods in Sonoran palo verde or Palo Brea (P. praecox), the Desert Museum hybrid palo verde (Parkinsonia x ‘Desert Museum’), and in other palo verde hybrids despite the absence of characteristic disease symptoms.

About 60 percent of the viral genome sequence is most similar to another plant virus named High Plains wheat mosaic virus, which is also transmitted by a species of eriophyid mite.

Other emaravirus species are known to infect European mountain ash (Sorbus aucuparia), fig (Ficus carica), pigeonpea (Cajanus cajan), raspberry (Rubus spp.), and rose (Rosa multiflora). The symptoms characteristic of emaravirus infection in these species are blotching, chlorotic ringspots, mottling of leaves, smaller than normal or stunted leaves, and densely clustered, multiple shoots.

Detection

Based on the results of a molecular detection test, the PVBV is present in shoots, leaves, flowers, seeds, and adventitious shoots from palo verde trees that show broom symptoms. The PVBV can also be detected in the leaves or shoots of trees that exhibit no characteristic disease symptoms. This may be because infection has occurred recently, and/or possibly because certain palo verde species may be tolerant to PVBV infection. However, the PVBV has been shown to be undetectable in many trees that have no broom symptoms, indicating they are likely not infected, and are virus-free.

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All known emaraviruses have been found to be transmitted by an eriophyid mite, making it the only known ‘biological’ vector. These arthropods are often host specific, meaning they populate only one genus or possibly a single species of plant. The presence of the eriophyid mite Aculus cercidi (Keifer, 1965) has been associated with broom symptoms in palo verde for some time, and it was suspected to cause feeding damage that resulted in the development of broom symptoms. However, until now, no causal relationship had been established between the eriophyid mite and the broom symptoms in palo verde trees.

Based on several years of collecting insects and arthropods from broom infested and healthy, non-symptomatic trees, we found consistently high populations of A. cercidi infesting trees with broom symptoms, while mites were in low abundance or rarely found in apparently healthy, non-symptomatic trees. Confirming the presence of the emaravirus in mites collected from broom infected trees provided further evidence of mites as the vector in transmitting the witches broom disease. This strong association between the presence of the emaravirus in broom of blue palo verde trees that were heavily infested with the suspected eriophyid vector, the absence of both the virus and vector on non- symptomatic trees, and presence of the virus in eriophyid mites, strongly support a causal relationship between emaravirus and the witches broom disease of blue palo verde.

Eriophyid mites are sometimes confused with spider mites. Eriophyid mites are wedge-shaped, very small, and require an approximately 20x magnification hand lens to see on a plant and at least 80x magnification to observe the different life stages more closely under a microscope. Identification of eriophyid mite species requires an image taken with an electron microscope and the assistance of a mite expert; mite samples we collected have been identified as A. cercidi using these tools.

There is no cure for witches broom in palo verde. Recommendations for limiting the spread of the virus causing witches broom in Parkinsonia species include controlling the eriophyid vector in nursery production and pruning out brooms in landscape trees.

Managing witches broom in nursery production:

• Ensure seeds for seedling production are from trees that show no broom symptoms because seeds may be infected by the palo verde broom emaravirus.
• Protect young seedlings from mite infestations by placing them in screenhouses and treating them with miticides.
• Discarding seedlings showing broom symptoms to reduce virus incidence in the propagation area. Small seedlings that display broom symptoms sometimes grow out of it based on our observation that broom symptoms disappeared as seedlings increased in size.

Managing witches broom in landscape trees:

• Prune trees without broom symptoms first, clean pruners between each tree. Based on similar plant/disease systems, it is likely that the emaravirus can be transmitted by contaminated pruners
• Cut out brooms, although they grow back in most cases. In our research we found almost year-round much higher numbers of eriophyid mites in broom tissue on trees in the landscape than on non-symptomatic trees. Removing the broom will remove large numbers of the eriophyid vector and potentially slow further infection of other trees.

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Before you build a coop and purchase your chicks, ensure chickens are allowed on your property. Some cities, counties, and homeowner’s associations (HOAs) restrict your ability to keep chickens or limit the number you’re allowed to have. They may also have rules on the setback and design of your coop or may allow you to have hens but no roosters. The best place to start is with local zoning requirements. 

Most of this information is available online, but it can be difficult to find or interpret, or in some cases may not be online at all. To look up your property's zoning code, you can follow these general instructions:

1. Determine if your property is located within city/town limits, or in an unincorporated area to know which zoning code will apply. This may be the “city” portion of your address, but it may not be if you are in an unincorporated county or census designated area. If you aren’t sure, check both sites in the second step to see where your address appears.
2. Locate the planning or zoning department website for your city/town/county. Most local governments have a department that handles planning and zoning. This section should have resources and tools for the public.
3. Locate the online zoning maps tool or address/parcel look up. Many municipalities provide interactive zoning maps where you can enter your property's address or parcel number to find its zoning designation. Look for a "Zoning Map" or "Interactive Map" option on the planning and zoning website. The zoning code may be provided in the form of a code (example, CR-1 or SR). You will need that code, and in some cases the officially listed square footage of your property (the lot size).
4. Check Zoning Ordinances. Once you know your zoning designation and lot size, access the zoning ordinance document for your area. This document outlines the zoning codes and regulations. This may be on the same website or included as a link when you look up your zoning code, or you may need to search for it (try a google search for “X county/city zoning code”). Find the zoning code within that document or website that applies to your property (example, CR-1 or SR). Chickens are considered livestock, and they may be included in the section that refers to general livestock, or they may have their own section separate from horses or other livestock. Be sure to read the entire zoning code pertaining to livestock. In addition to whether birds are allowed, it may specify what types/species/sexes, how many (which may be based in your lot size), setbacks for coops, manure or noise management or other restrictions.
5. Be aware that Homeowner Associations (HOAs) or deeds may have more limitations than zoning codes. 

If you’re still having trouble, Contact your local planning or zoning department. Staff can help you find your zoning code and provide the zoning ordinances to you. 

For any address in Pima County:

1. Pima Zoning Search Page. Enter the number portion of your address into the "Street Address Number Search Box" and click "Search."
2. Scroll down to find your street address, then click on "Parcel info" on the left side of the screen.
3. Scroll to the section titled "100+ parcel details from GIS overlay analysis" and in the table select "Zoning."
4. Scroll down to the table titled "Zoning." Note under the table the listed parcel size in square feet for your address. The zoning codes that apply to your address will appear in the table as clickable links. Select the zoning code link (example: CR-1) to view the permitted uses for your zone. Be aware that HOAs or deed restrictions may be more restrictive than the zoning code.

Only for unincorporated Cochise County.

• Cochise ARC GIS – Use this to find the zoning code for your property.
• Cochise County Zoning – Click on “Zoning/Permitted Use Table” (this is also linked for you when you click on your property in the map above).

• If you haven't already, move cold-sensitive potted plants indoors. This includes adeniums (desert roses) and other
  vulnerable succulents like pachypodiums and certain euphorbia. Place them in a sunny spot but keep them away from
  direct heat sources like vents.
• Watch for cold nights and protect plants as needed. Many plants are sensitive to 40 degrees, while others can tolerate much lower temperatures. Knowing your USDA Plant Hardiness zone helps localize your temperature expectations for plant protection.
• Do NOT prune frost-damaged plants until the danger of freezing is past. Pruning now will only stimulate new plant growth,
  which is not recommended.
• Cap cold-sensitive cacti, such as totem pole, golden torch, Mexican fencepost, and young saguaro. Use a paper grocery
  bag or large Styrofoam cup to protect the delicate growing tip from the cold. Do not use plastic in direct contact with the
  plant; it will conduct cold not insulate. After the freeze, remove the cap, but keep it – you can reuse.
• Pick exposed lemons and limes before a hard freeze. Some damage to these fruits on upper and outer portions of the tree
  will occur when temperatures drop to 28 degrees. Other types of citrus fruits can handle cold temperatures better.
• Begin harvesting grapefruit at the end of the month, picking only those you need. The longer they stay on the tree, the
  sweeter they become. Fruit may be left on the tree for several months. Nearly all varieties of grapefruit that are suitable for
  our location are frost-hardy.
• Prune non-native deciduous trees and shrubs while dormant. Natives are best pruned when temps are warm.
• Delay pruning your spring-flowering shrubs until after they bloom.
• If you've previously had pest infestations on your roses, grapes, or deciduous flowering and fruiting trees, consider
  spraying the foliage with horticultural oil to kill overwintering insects. For the best results, apply the oil after winter
  pruning. Ensure thorough coverage, as the oil works by smothering insects hidden in the nooks and crannies of the woody
  growth.
• Keep poinsettias healthy by locating them away from drafts and direct sunlight. They prefer bright, indirect light during the
  day and a cool location at night. Keep the soil evenly moist, as over- or under-watering will cause the leaves to yellow and
  drop off. Fertilize monthly with a water-soluble “balanced” houseplant fertilizer. After all danger of frost is over,
  poinsettias can be planted outside in a shady location.
• Apply Btk (Bacillus thuringiensis kurstaki) if caterpillars are damaging your cabbage, lettuce, broccoli, or cauliflower. Btk is
  safe for animals and humans but is lethal to all larvae of the Lepidoptera family (butterflies and moths). While effective,
  use it with care to avoid harming beneficial species.
• Now is a good time to consider planning or installing active or passive rainwater harvesting.

• Plant cold-hardy flowers into the ground such as snapdragons, nemesia, petunias, pansies, stock, alyssum, million bells
  (Calibrachoa), and geraniums. Choose a sunny spot as the flower yields will be improved.
• Seeds of cool-weather vegetables can be planted directly into the soil. Examples are leaf lettuces, peas, radishes,
  carrots, chard, kale, parsnips, and beets.

• Continue with mild fertilizing of winter vegetables.
• Over-seeded Bermudagrass lawns need applications of a nitrogen fertilizer once per month.
• Other uses of fertilizer are not advised. Fertilizers stimulate new growth that will be frost-sensitive.

• Adjust your outdoor irrigation frequencies (not duration) for December. If there are ample rains, consider turning your
  system off. Keep an eye on your tender annual plants to ensure they are receiving adequate moisture.
• If you brought potted succulents indoors to protect them, water these very sparingly during this time. 

USDA Plant Hardiness map

Problems and Pests of Agave, Aloe, Cactus and Yucca

Protecting a Citrus Tree from Cold

Ten Steps to a Successful Vegetable Garden

Landscape management practices for passive water harvesting

Harvesting rainwater

Flower Planting Guide for the Low Desert

Fertilizing Home Gardens in Arizona

Training and pruning fruit trees

Pruning Deciduous Shade Trees

For more information on any of these topics, search our database of Extension publications going back more than 100 years housed in the University of Arizona Campus Repository.

• The first frost sometimes occurs in mid-to-late November. Prepare by obtaining frost cloth, sheets, utility lights or re-use
  incandescent C-7 or C-9 Christmas lights (not miniatures or LED). Be sure to protect any light bulbs from accidental
  damage and do not allow contact with cloth coverings. Protect plants as needed; some portions of your yard may be
  colder than others.
• Do general garden cleanup. Pull weeds before they go to seed.
• Remove dead or dying plants and rake up fallen leaves to compost them if not diseased.
• Replenish organic mulches to a depth of 3-4 inches for soil temperature and moisture control as well as weed prevention.
  Refresh any decorative stone landscape materials.
• If prickly pear cacti have a cottony substance on them known as cochineal scale, a strong spray of water from a garden
  hose will remove most of it. Heavily infested pads should be cut off at the joint and discarded; do not compost.
• Remove spent blooms of flowers such as petunias to increase flower production.
• Move adenium (desert roses) and other cold-sensitive succulents such as pachypodium and certain euphorbia to a
  protected area or move them indoors for the winter. Provide them with a sunny spot until outdoor nighttime temperatures
  return to the mid-50’s.
• Protect young vegetable and flower transplants and seedlings from cutworms by placing a ring cut from a paper or
  Styrofoam cup around the transplant at the soil line to protect the stem. The rings can be removed after a week or 10 days.
• Plan and implement hardscaping & water harvesting projects while the temperatures are cooler and rain is minimal.

• Early in the month, sow seeds directly into the ground for beets, carrots, peas, onions, chard, spinach, kale, endive, and
  turnips. Space them appropriately to allow for plant and root growth.
• Transplant broccoli, cabbage and cauliflower starts into the ground or raised beds.
• Early in the month sow seeds directly into the ground for spring-flowering wildflowers such as California and Mexican
  poppies, cowpen daisy, desert blue bells, desert marigold, tidy tips, and white chicory; keep the area moist but not damp
  until seeds germinate. Be sure the chosen location will not be too shaded when Spring comes; they love sun.
• Plant flowering perennials such as gaura and angelita daisy.
• Plant spring-flowering bulbs such as bearded iris, hyacinth, crocus, daffodils, and narcissus for a burst of color after
  Winter.
• This is a good month to plant trees, shrubs, ground covers, vines, herbs, and winter vegetables purchased from nurseries
  before the first frost.

• Vegetables require light fertilization throughout the growing season. There are various fertilizer options, including organic
  and chemical fertilizers. When using organic fertilizers, it's important to apply them early to allow sufficient time for
  breakdown, ensuring a steady nutrient supply as plants grow. 
• Do not fertilize citrus, roses, or frost-tender plants, as this may encourage tender new growth susceptible to damage.
• Fertilize winter lawns monthly to retain good color.

• Adjust your irrigation frequencies (not length of time) for November.
• Continue to water your fall wildflowers.
• If you brought potted succulents indoors to protect them, water these very sparingly during this time.
• If you see fungus or mushrooms, cut back on watering in that area.
• Irrigate in preparation for cold nights except for cacti/succulents. Moist soil will store heat from the sun’s energy and
  release it at night, keeping these plants warmer.
• Importantly, if a freeze is predicted, do not water cacti or other succulents

Small Scale Composting in the Low Desert

Flower Planting Guide for the Low Desert

Landscape management practices for passive water harvesting

Harvesting rainwater

Ten Steps to a Successful Vegetable Garden

Organic Fertilizer

Fertilizing Home Gardens in Arizona

Spring Flowering Bulbs

Container trees and shrubs

Training and pruning fruit trees

Planting and staking trees

Problems and Pests of Agave, Aloe, Cactus and Yucca

For more information on any of these topics, search our database of Extension publications going back more than 100 years housed in the University of Arizona Campus Repository.

• Warm-season flowering plants and vegetables (squash, melons and summer – not fall – harvested varieties of corn)
  can be removed to make room for cool-season ones. Consider adding them to your compost if not diseased.
• Do not perform major pruning on trees or shrubs unless plants are very leggy, unsafe or intruding on walkways. Protect newly-planted citrus from low temperatures.
• Prune roses lightly if you did not perform this task in September. Remove weak or spindly canes which are less than
  pencil-sized in thickness. The major annual rose pruning is recommended for mid-January to mid-February.
• Ensure you have frost cloth ready to avoid being caught off guard by a sudden freeze warning. Use it to protect coldsensitive plants. Be aware of your plants' frost sensitivity and how cold it gets in various parts of your yard to be
  prepared to cover them when necessary.
• When temperatures begin to dip, bring frost-sensitive potted succulents indoors, including all adeniums and
  pachypodiums, and certain euphorbias. Give them a sunny spot until nighttime temperatures reach the mid-50’s.
• Mulching (3 inches or more) helps your plants withstand the colder temperatures coming later in the month. Keep the
  mulch a few inches away from the trunks.
• Plan and implement hardscaping & water harvesting projects while the temperatures are cooler.
• If you notice powdery mildew, no treatment is recommended as it comes and goes as temperatures fall. If it’s on aged
  plants, remove and trash the plant (not compost it). Soft bodied pests indicate an annual plant is at the end of its life.
• Although turfgrasses are highly water-intensive, if you have them, overseed your Bermudagrass with annual rye or other
  winter grasses once the daytime temperatures are < 90 ⁰F and it is in the 60s overnight. Be sure to cut your
  Bermudagrass short before overseeding.

• Plant trees and shrubs of all types early in the month. Warm soil temperatures and cooler air
  temperatures combine to provide ideal conditions for the establishment of new landscape plants. Although it may
  seem counter-intuitive, trees in smaller 5-15-gallon containers will establish and grow faster. Select and plant trees –
  including citrus varieties - so that the top of the root ball is level with or slightly higher than the surrounding soil.
• Early in the month sow seeds outdoors (or plant starts) of vegetables such as arugula, beets, broccoli, carrots,
  brussels sprouts, cabbage, cauliflower, chard, spinach, kale, lettuce, leeks, bok choy, and spinach.
• By mid-month, sow from seed vegetables and herbs such as cilantro, dill, Mexican oregano, parsley, sage, rosemary
  and thyme.
• Plant cool-season annual flowers now so that in Spring they will flower. Examples are petunias, penstemon,
  snapdragons, violets, alyssum, dianthus, and calendulas.
• Plant perennials such as Angelita and Blackfoot daisies, black dalea, desert mallow, evening primrose, germander,
  Mexican honeysuckle, penstemon species, red justicia, Russian sage, salvia species and verbena.
• Soil temperatures remain warm enough to plant or transplant cacti and succulents into the ground. Winter transplants
  experience delayed root growth due to cool soil.

• Fertilize roses of all varieties for the last time this calendar year.
• Fertilize new plantings of flowers and cool-season vegetables with a high-phosphorus mixture for root growth.
  Continue fertilizing your established flowers and vegetables.
• It is past time to do any citrus fertilization until the new year.

• Adjust your irrigation frequencies (not length of time) for October.
• For lawns, consider shifting your irrigation start/end times as it cools to more daylight hours to prevent fungal growth.
• If you brought potted succulents indoors to protect them, water these very sparingly during this time.
• Water newly planted native and desert adapted plants (not cacti or succulents) with a gradually less-frequent
  schedule.

Ten Steps to a Successful Vegetable Garden

Selecting and Planting a Saguaro

How to Transplant a Cactus

Cactus, Agave, Yucca, and Ocotillo

Irrigating Citrus Trees

Overseeding Winter Grasses into Bermuda grass

Fertilizing Home Gardens in Arizona

Citrus Fertilization chart for Arizona

Efficient landscape watering

Landscape management practices for passive water harvesting

Harvesting rainwater

Container trees and shrubs

Training and pruning fruit trees

Planting and staking trees

For more information on any of these topics, search our database of Extension publications going back more than 100 years housed in the University of Arizona Campus Repository.

• Take the opportunity to clean up any monsoon damage.
• Discard split citrus and pomegranate fruit. Damaged fruit will attract fruit flies and other insects.
• Help plants recover from summer heat by pruning off dead and dried branches.
• Lightly prune roses and remove old or dead canes in mid-September. Remove spent blooms. Pick up and discard
  all cuttings as they can harbor insects and diseases.
• Deadhead spent blooms and prune back leggy plants.
• Pull weeds before they set seed.
• In garden beds, mix in a starter fertilizer containing both nitrogen and phosphorus before planting.
• As the sun begins to shift, relocate container plants to sunnier locations.
• Hose off susceptible plants that are dusty to control spider mites.
• If you notice something that looks like bird droppings on citrus trees, it could be the orange dog caterpillar which
  matures into the giant swallowtail butterfly. These will not cause major damage to a mature plant, but you may
  wish to pick them off a younger plant.
• Divide iris beds every 3 to 4 years.

• Plant flowering bulbs such as amaryllis, narcissus, iris, rain lilies, and ranunculus. Choose a location with morning
  sun. Keep soil damp but not wet. Use mulch to hold in moisture.
• Vegetables and non-native annuals require enriched soil.
• Sow seeds indoors for cilantro, chives, parsley, sage, thyme, and oregano. Winter herbs prefer sunshine and
  monthly feedings once transplanted into the garden.
• Sow seeds for carrots, radishes, spinach, lettuces, turnips, green onions, beets, chard directly into the garden by
  mid-month.
• Sow seeds or plant transplants of sweet peas, French marigold, snapdragon, lobelia and dianthus.
• Sow seeds of broccoli, cabbage, cauliflower, brussels sprouts in trays to be transplanted next month.
• Plant strawberry plants where they will receive protection from afternoon sun.
• Plant deciduous fruit trees that do well in the desert, such as figs and pomegranates.
• If you prefer not to plant any fall veggies, consider planting cover crops like hairy vetch, annual rye, peas or clover
  which will help maintain your soil's porosity and even potentially fix nitrogen into depleted soil.

• September is the time to do the 3rd citrus feeding of lemons and limes, if you did not already do so in August.
• Feed stone-fruit trees such as apricots, peaches, and plums in elevations over 3500’. These nutrients will be
  stored in the tree roots for use in the spring. For lower elevations, hold off on until spring.
• If you have roses, return to full-strength slow-release fertilizer this month.
• Fertilize beds of greens and herbs using a balanced fertilizer before planting.

• Adjust irrigation frequency based on the rains, maintain your summer schedule until temperatures drop.
• Continue to keep an eye on pomegranate and citrus trees for fruit splitting. This could be an indication of too
  much water for the former and/or sun-damaged rinds that cannot expand for the latter. It is important for these
  trees to have a consistent watering schedule.
• Monsoon rains are subsiding and now is a good time to consider adding passive and/or active rainwater
  harvesting.

Irrigating Citrus Trees

Backyard Fruit Production at Elevations 3500 to 6000 Feet

Ten Steps to a Successful Vegetable Garden

Diagnosing Home Citrus Problems

Planting and staking trees

Training and pruning fruit trees

Citrus Fertilization chart for Arizona

Fall Bulb Planting Time

Bearded Iris, Backyard Gardener

Giant Swallowtail

Extension Monsoon page

For more information on any of these topics, search our database of Extension publications going back more than 100 years housed in the University of Arizona Campus Repository.

• As the monsoon wanes, consider installing active or passive rainwater harvesting systems.
• It may be too hot for tomatoes to set fruit in August, so consider pruning tomatoes by two-thirds for a
  second, fall harvest. Discard or compost the cuttings.
• Unless monsoon-damaged, avoid heavy pruning of most varieties of trees and shrubs. Removing too
  much leafy growth opens the center of the plant to direct sunlight which can scorch lower leaves,
  branches, and trunk not used to that exposure. Remember that loss of shade can adversely affect
  the plants (formerly) underneath. Routine or heavy tree pruning jobs are done later in the year.
• Native trees, such as mesquite and palo verde, however, can be pruned now because they heal
  better during the heat of the summer.
• Dethatch lawns early this month to allow time for the grass to recover before fall. Thatch is an
  accumulation of dead grass plants and roots that covers the soil and forms a dense mat that restricts
  the movement of water and fertilizer. Take a vertical plug out of the lawn and soil to check the depth
  of the spongy thatch layer. If this layer over the soil is one-half inch or thicker, it should be removed
  with a steel tine lawn rake or power dethatcher.
• Keep checking plants for signs of water stress and sunburn.

• Plant bush beans, cowpeas, corn, snap peas, radish, kale, beets, and turnips from seed.
• Start broccoli, cabbage, cauliflower, and brussels sprouts in trays to transplant to the ground or
  raised beds in October.
• Research which trees would best fit your garden for planting next month. Be sure you know the
  expected mature size.
• Tucson Electric Power customers can reach out for information and eligibility on discounted shade
  trees.
• Cacti and agave can continue to be planted or transplanted this month.
• Now is a good time to plant native and near-native perennials.
• Research which cool-season vegetables and flowers you might want to grow - even if not planting
  now.

• For lemon and lime trees, apply the last third of the annual feedings in August-September. Be sure any soil or mulch has not washed in from
  watering or monsoon. It should not sit too close to the trunk.
• For those with roses, you have two choices:
  • Option 1: Give your roses a break during July and August with no fertilizer applications. Start
    back with full-strength slow-release fertilizer in September.
  • Option 2: Continue using slow-release fertilizer at half-strength throughout the summer,
    then change back to full-strength applications as above.
• Continue fertilizing flowers, vegetables, and lawns that may be nutrient-depleted from the washingeffect of monsoon rains. If plants turn a pale green or have reduced growth, flowering, or fruiting, they probably need to be fertilized.
• Prepare in-ground or raised garden beds for fall planting by adding aged compost and/or composted
  steer manure.

• Adjust irrigation for all your plants based on the intensity of your local monsoon.
• If your citrus fruit or pomegranates are splitting, they may be getting too much water. Adjust your
  watering frequency, but not the duration.
• Trees and large cacti may need a deep soaking if your local monsoon is sparse.
• Succulents should be carefully monitored for appropriate watering.

Ten Steps to a Successful Vegetable Garden

Citrus Fertilization chart for Arizona

Harvesting rainwater

Irrigating Citrus Trees

Citrus Fertilization chart for Arizona

Rose Selection and Planting in the Low Desert

Fertilizing Home Gardens in Arizona

Mesquite and Paloverde trees for the Urban Landscape

Pruning Deciduous Shade Trees

Efficient landscape watering

Landscape management practices for passive water harvesting

Landscape Practices for Extreme Heat and Drought

For more information on any of these topics, search our database of Extension publications going back more than 100 years housed in the University of Arizona Campus Repository.