Handout
Authors
Paul Larson
Laurie Vance
Deborah North
Publication Date: January 2025 |
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Garden in the morning and golf in the afternoon (or vice versa!) in some of the most perfect weather in the 50 states. With highs in the 70’s and lows in the high 40’s, March is a beautiful month to be outdoors. This is the perfect time to spring into action and get your warm season garden started. There are also plenty of maintenance tasks to perform between cleaning up and trimming dead or damaged plants from winter. This is a great time to create the landscape you’ve always wanted!
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Maintenance
- Average last frost date is March 15. In the warmer areas of Pima county, it may be a bit earlier and may have already passed – but for others in colder locations, stay vigilant. Refer to Frost Protection and Protecting a Citrus Tree from Cold for more information. After your last local frost, store your frost cloth and cactus covers for use next year.
- Remain vigilant controlling weeds. The best method for control is manual removal and this is far easier when weeds are young. Be aware of invasive weeds such as stinknet and report them immediately even if not in your own garden - this invasive produces thousands of seeds per flower. Visit stinknet.org for more information.
- For those who live in brushfire areas, March is a great time to review your defensible space. This area around your home and garden is one of your primary determinants for wildfire survival. Visit our wildfire topic page or read Fire-Resistant Landscaping for more information.
- Prune winter damage after danger of freezing has passed. Check the stems for signs of life. With a sharp knife, peel back a small area of bark on the outer stems. If there is green sapwood underneath, do not prune these stems as new growth will soon appear. If the wood beneath the bark is dry and brown, prune back to live wood. Information about pruning is available in Pruning Deciduous Shade Trees and Training and Pruning Newly Planted Deciduous Fruit Trees.
- Thin fruit on deciduous fruit trees including apple, peach, plum, nectarine, and apricots. Thinning reduces weight and limb breakage, improves color, size, and quality. Leave about 6 inches between fruit. This is best done when the fruit is small--about marble-sized. For heavy producers, this may need to be repeated as the fruit size increases, so observe and remove fruit as needed to ensure the tree can carry the load.
- After the last frost of the season, inspect your citrus for signs of dead, damaged or dying branches. These should be pruned before the heat sets in. Any growth coming from below the graft joint (near the base of the tree) should be pruned as well. These are growing from root stock and do not bear edible fruit. Citrus are best left in a shrubby shape. If you prune and expose the lower trunk, now is the time to paint the exposed, tender area with white, water-based paint for protection. More information is available in Pruning Citrus.
- Monitor new growth and the undersides of leaves for soft-bodied pests such as aphids, whitefly, and thrips. Insects become active as temps warm and they are ready to feed. Avoid the use of chemical control and use a firm blast of water to knock them off the plant. If sticky honeydew is present, add one tablespoon of liquid dish detergent to one gallon of water and spray the tops and bottoms of leaves. These pests can reproduce rapidly, so multiple treatments are likely. Recurring issues with these pests mean that you should check your fertilizing and watering schemes to ensure you are not overdoing them and causing too much new growth – a common reason for pest infestations. More information is available in Aphids.
- This is an excellent time to plan or install active or passive water harvesting systems. Those with Tucson city water should investigate rebates. Learn more by reading Landscape Management Practices to Optimize Passive Rainwater Harvesting and Plant Health, Harvesting Rainwater for Landscape Use, and the City of Tucson Water Rebates page.
Planting
- March is one of the best times to plant new landscape plants. Warm soils and mild temperatures enable plants to establish themselves before hot weather sets in. Refer to Plant Selection for more information.
- Sow annual seeds into the soil for coreopsis, cosmos, marigold, and zinnia.
- Plant perennial flowers from seed or seedlings: angelita daisy, bee balm, blackfoot daisy, California fuchsia, chocolate flower, golden dyssodia, lantana, prairie zinnia, salvias (sages) and tufted primrose. It’s also a great time to plant summer wildflowers from seed following information in Flower Planting Guide for the Low Desert.
- Plant or transplant shrubs such as fairy duster, bee bush, black dalea, little-leaf cordia, Texas rangers and yellow bells.
- Plant tomatoes into the soil about mid-March, since they thrive in temperatures between 50°F and 90°F. Choose short-season varieties that generally mature within 70 days as outlined in Growing Tomatoes.
- Plant trees and shrubs of all types into the soil, including citrus. Presentations materials in Selecting, Planting, and Staking Trees have more information.
- Plant or transplant container roses now to allow establishment before hotter daytime temperatures arrive. Learn more by reading Rose Selection & Planting in the Low Desert.
- Vegetables and Herbs: Sow seeds outdoors or plant starts for sweet corn, bush beans, lima beans, spring peas, leafy greens, summer squashes, tomatoes, Mexican oregano and rosemary. Getting an early start means vegetables will be ready prior to the withering heat of June. Follow steps listed in Ten Steps to a Successful Vegetable Garden.
Fertilizing
- Fertilize citrus (2nd of 3 annual feedings). For oranges, tangerines, and grapefruit, the first1/3 of the total was in January-February, the second 1/3 in March-April, and the last 1/3 in May-June. For lemons and limes, the first two applications are the same, but the last 1/3 isn’t until August-September. Refer to Diagnosing Home Citrus Problems and Citrus Fertilization Chart for Arizona for more information.
- If you did not fertilize deciduous fruit trees (apples, pears, pomegranates, figs, etc) in February, do it this month. Fertilizers should contain all the macronutrients.
- Do the first feeding of tomatoes this month with a balanced fertilizer.
- Other uses of fertilizer in your garden are not advised unless past your last frost date. Remember that they stimulate new growth that will be frost-sensitive.
Watering
- Check and adjust irrigation frequencies based on local rainfall.
- Check your irrigation systems to ensure they are working properly as outlined in Drip Irrigation: The Basics.