Guide
Authors
Paul Larson
Laurie Vance
Deborah North
Publication Date: January 2025 | Revision Date: 09/01/2024 |
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Yes, June is hot. But turn your focus in amazement now to our native flora. The Sonoran desert is the home to one of the most biodiverse deserts in the world and we gardeners have a front row seat. This month our non-native plants will need your attention to keep them happy. Make sure to practice self-care as we unfortunately cannot cope as well as our native plants. But remember that without the intense heat of June, there would be no monsoon season and no Sonoran desert.
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Maintenance
- Personal Safety is your top priority in the garden this month. Drink lots of water regularly, and do not wait until you are thirsty. Wear sunscreen, sunglasses, and a wide-brimmed hat. Avoid outdoor work between 10 and 3 o’clock. Plan ahead for taking rest breaks in shaded areas.
- Check your drip irrigation systems for leaks and other maintenance needs following instruction in Drip Irrigation: The Basics.
- Check plants daily for signs of water stress and sunburn; cover with 30-40% shade cloth if needed.
- For those who live in brushfire areas, June is a great time to review your defensible space before monsoon lightning storms begin next month. This area around your home and garden is one of your primary determinants for wildfire survival. Protect Your Home From Wildfire has more information.
- Once temperatures are consistently above 95 degrees, vegetable gardens may become less productive. Maintain ample watering schedules and consider adding shade cloth to get the plants through this challenging time. Add compost as needed to help cool the soil and reduce evaporation. Tomato plants can be cut back by 30% in size to reduce stress. Refer to Growing Tomatoes to learn more.
- Remove wilted tomato and pepper plants. If you are concerned that the issue may be caused by a pest or disease, contact our Plant Clinic for diagnosis and advice on treatment.
- If your squash are not producing, consider hand pollinating to increase fruit set. In early morning, transfer pollen from the powdery yellow anther to the sticky female stigma by breaking off a male flower and brushing the pollen onto the female stigma. Female blossoms have baby squash under the flower, a slight swelling, while male flowers do not.
- Dead-head garden flowers such as marigold, geranium, zinnia, and roses. Removing faded blossoms before they go to seed will encourage your flowers to continue blooming. Cut faded flowers off with scissors or clippers; do not pull them off. Cutting the stem below the flower ensures the removal of the seed producing ovary.
- Plan or install active or passive Water Harvesting systems to capture the rainwater before monsoon begins. Read Landscape Management Practices to Optimize Passive Rainwater Harvesting and Plant Health and Harvesting Rainwater for Landscape Use to learn more.
- Mulch to a depth of 3-4 inches around trees and shrubs. Be sure the mulch is away from the trunks a few inches; don’t make a “mulch volcano” – as this can harm the plant. Selecting, Planting, and Staking Trees provides additional information.
- Citrus trees need as much foliage as possible to protect their delicate trunks, especially during high heat. Remove any sprouts or suckers that grow from below the graft joint (bud union), as these come from the rootstock and won’t produce edible fruit. Also, prune vertical sprouts with thorns that appear above the bud union. If wind damage occurs and poses a risk, be sure to remove any affected wood as well. Pruning steps are available in Pruning Citrus.
Planting
- June is a hot, dry month that is not the best for planting trees or shrubs; pay extra attention to anything newly planted whether in the ground or in a container.
- If you are not planting your vegetable garden during the summer, consider planting a cover crop that will keep the soil from going fallow. Cowpeas (Black Eyed Peas) or peanuts are ideal cover crops for the Sonoran desert. Read Summer Cover Crop Use in Arizona Vegetable Production Systems to learn more.
- Beans are legumes that enrich the soil, and many varieties thrive in high heat. Consider growing yard-long beans (also known as asparagus beans), cowpeas, or Tepary beans. Native Seeds/SEARCH offers numerous heat-tolerant varieties that will produce throughout summer and into fall. Using a trellis or other support at least 6 feet tall helps these plants thrive. When planted on the west side of your vegetable garden, trellised beans can also provide shade for more delicate plants (Refer to the Native Seeds website in the references).
- Plant seeds of muskmelon, okra, squash, sweet potato slips, corn, and zucchini. Ten Steps for a Successful Vegetable Garden has more information.
Fertilizing
- Apply a balanced fertilizer at half-strength to container plants that are not cacti every two weeks.
- If not already done in May, apply the third of 3 annual applications of fertilizer to orange, tangerine and grapefruit trees following recommendations in the Citrus Fertilization Chart for Arizona. Lemons do not receive their last application until later in the year.
- Fertilize palms with a palm-specific fertilizer and then be sure to water it in within 24 hours. These formulations will have roughly 3X the usable amounts of nitrogen and potassium when compared to phosphorous as well as some other micronutrients. Read Arizona Landscape Palms to learn more.
- Vegetables may need a side-dressing of fertilizer this month. You can also consider compost or a fish fertilizer solution.
- Roses will need an application of fertilizer about every 3 to 4 weeks.
Watering
- Water most container plants once daily this month; early in the day is best.
- Moving containers to an area with afternoon shade or that is protected from wind and adding mulch are techniques to reduce moisture loss. Remember that hot dry winds increase evapotranspiration moisture loss.
- This guidance does not apply to cacti and succulents, which remain resilient and require far less water, even during the most demanding parts of the year. Their ability to store water allows them to thrive despite the heat, making them an exception to the rule of frequent irrigation.
- Use a soil probe to check if water is getting down to the appropriate depth for shrubs (24”) and trees (36”). Refer to Watering Trees and Shrubs: Simple Techniques for Efficient Landscape Watering and Irrigating Citrus Trees to learn more
- Prevent blossom end rot (a calcium uptake issue for the plant) in the vegetable garden by maintaining even and consistent watering. Blossom end rot causes a black or brown sunken area to develop on the bottom (blossom end) of fruit. It is particularly common on tomatoes and peppers but can affect other fruits and vegetables.
- Bermudagrass turf may need watering every 3 days. A Turfgrass Maintenance Guide for Residential and Commercial Lawns in the Low Elevation Arizona Desert has more information.