April/May 2022 Garden Checklist and Solutions
What to Plant: Low Elevations
Watch nurseries for sweet potato “slips,” which are sprouted cuttings from the root tuber. Plant slips 4-6 inches deep in the soil, and cover with planting row covers to protect against whitefly and other pests. If you can’t find slips to purchase, grow your own by cutting small sweet potatoes from the grocery store in half and suspending each piece with toothpicks in a glass of water so that half of the tuber is above and the remainder below the water line. Once roots develop in the water and shoots sprout in the air, transplant into the garden.
Unless someone in your household suffers peanut allergies, growing this groovy legume at home is great fun. Purchase raw peanuts and remove the seeds from the shell (the seed is the part we eat). Plant the seeds 2 inches deep in a location that gets at least eight hours of sunlight per day. Once the first yellow flower appears, usually about a month later, mound soil around the base of the plant. This is where the “pegs,” or pointy stems, dive underground after blooming and the peanuts develop. After 4-5 months, the leaves should start to turn yellow. At this time, cut back on watering for two weeks before carefully pulling the entire plant out of the ground. Shake off the excess soil, but leave the peanuts attached to the roots to dry in a protected, dry place for about one week.
What to Plant: Low and Middle Elevations
Feed yourself and wildlife with low-maintenance, drought-tolerant, native edibles. Velvet mesquite (Prosopis velutina) is a medium-sized tree and produces pods that can be ground into flour. Prickly pear cactus (Opuntia engelmannii, among others) has edible, green pads and sweet, red fruits. Wolfberry (Lycium fremontii) is our native goji berry, with small, tart fruits that look pretty in a salad or can be made into jelly. Learn more about planting an edible landscape on April 19 at a class hosted by Tohono Chul in Tucson. Visit tohonochul.org/event/edible-landscapes to secure your seat.
This fragrant herb thrives in warm, dry weather. Available in seemingly endless color and flavor varieties, there is a basil to complement just about any garden bed and cuisine. Start seeds indoors 3-4 weeks before transplanting outdoors, or pick up transplants at your local nursery. Grow basil in a sunny location and pinch back the ends of shoots to keep the plant compact and bushy.
What to Plant: Middle Elevations
Heat-loving crops such as okra, cucumbers, squash and bush beans can be direct-seeded into garden beds. Protect new plantings from insect and bird pests by covering with floating row covers, available at most garden supply shops.
What to Plant: High Elevations
NATIVE TREE SEEDLINGS
Help clean up the Arboretum at Flagstaff and plant tree seedlings during their Arbor Day Clean-Up-Alooza on April 30. Volunteers can take home native tree seedlings to plant in their own landscape. Learn more and register for the event at thearb.org/calendarofevents.
Once soil temperatures reach 70 degrees, usually around mid-May, transplant tomatoes directly into garden beds—or, if space is limited, containers. Select containers that can hold at least 5 gallons of potting mix to provide ample rooting volume. Tomatoes can be planted more deeply than most other vegetables; doing so will encourage root growth along the stems to boost water absorption. Remove all branches and leaves on the lower two-thirds first, then plant in garden soil leaving only the top one-third above ground.
Garden Maintenance: All Elevations
As temperatures warm, water garden and landscape plants more frequently. Remember, the same amount of water should be applied every time you irrigate, but do it more often during hot, dry weather and less often when conditions are cool and/or humid.
SCOUT FOR PESTS
Early detection and intervention are the most sustainable approaches to managing pests in the garden and landscape. Always be on the lookout for newly sprouting weeds and pluck them immediately. Scan the tops and bottoms of leaves in vegetable, herb and flower gardens for the telltale signs of insect or mite damage. Choose solutions that have minimal impact on the rest of the of the environment.
Garden Maintenance: Low Elevations
TRANSITION OVERSEEDED LAWNS
Once nighttime temperatures stay above 65 degrees for a few days, usually in late April or early May, discourage winter ryegrass by lowering the mower height to remove 50% of the leaf blade. Skip watering the turf for about a week to shock the rye, then resume irrigation. Next, fertilize with 2 pounds of ammonium sulfate per 1,000 square feet of lawn every other week until the awakening Bermudagrass has almost completely overtaken the rye. Keep the mowing height around 1.5 inches and water the Bermuda as dictated by current weather conditions.
Garden Maintenance: Middle Elevations
Layer 3-4 inches of mulch around trees, shrubs and perennials to conserve soil moisture and suppress weed germination. Never mound mulch against the trunks of any plants, as this may lead to many problems, including weakening the trunk and encouraging girdling roots.
Garden Maintenance: High Elevations
PRUNE SPRING BLOOMERS
Keep spring-blooming shrubs and perennials looking fresh by deadheading faded flowers. May is a good time to thin shrubs that finished blossoming for the year. Remove the oldest branches all the way back to ground to encourage new growth. Don’t go crazy—removing more than one-third of an actively growing plant can stress and weaken it.
I sprayed bermudagrass that was smothering our raised vegetable garden with a glyphosate herbicide last summer, and now my wife says we can’t grow food in that soil anymore. I read the bottle, and it said it was safe to plant vegetables three days after spraying weeds. Do we really need to replace the soil in the beds?
The pesticide label is the law, so it is illegal for a company to make a false safety claim on an herbicide bottle. Assuming you used the product as directed on the label, applied it only to the grass and effectively killed it, there is no reason to believe there is any residual in the soil a year later. Glyphosate (another herbicide) use is widespread in the conventional agriculture that feeds most people, so unless you only eat certified organic food, whatever vegetables you grow and eat from your beds will probably be as safe as anything else in your diet.
Limbs from the neighbor’s tree reach into our Gilbert yard and brush against a second-floor window. The neighbors have lived behind us for years, but we’ve never spoken. What can we do?
Sounds like the tree is too big for the space if it’s scratching at your window. Ideally, a licensed arborist would work with the tree owner to discuss the correction options that are best for the plant’s health. Most municipalities allow you to cut back intruding plants on your side of the property line, as long as you don’t murder the plant completely. If knocking on their door to talk boundaries is not a possibility, you can lop branches yourself, or better yet, hire an expert to do the job.
There are small, white specks on the leaves of my jade plant. Should I be concerned that it has a disease?
Does your houseplant look healthy, other than the white specks? Are the leaves yellow; do they have brown spots; or are they dropping off? If so, check if the soil is saturated with water. Poor drainage or overwatering may encourage the growth of bacteria or fungi that can harm the plant. Promptly dispose of fallen, affected leaves, and let the soil dry out. If the white spots rub off, those spots may be mealy bugs, a type of insect that feeds on plant leaves. Mealy bugs secrete a waxy substance that gives the spots a powdery or fuzzy appearance. Wipe the pests off with a cotton ball dipped in rubbing alcohol. If it is heavily infested, it is probably best to discard the plant and start anew. If the spots wipe off but feel grainy or crunchy, they may be salt crystals that formed on the leaves. This is a signal the plant was overwatered and salts were pushed to the surface of the leaves. Wipe the crystals off, ensure good soil drainage and water less frequently to prevent further occurrence.