The Dirt on May

Cara Beth Graebner
3 days ago
5 min read

By May, the garden has stopped being theoretical. The seed packets, soil test notes, and “I’ll get to that this weekend” plans have officially met real weather, real weeds, real bugs, and real hungry gardeners. This is the month when cool-season crops come off at their best, warm-season crops move in for the long haul, and the gardener’s job shifts from “getting ready” to “paying attention.” The May pages of the Tennessee Home Fruit and Vegetable Garden 2026 Calendar focus on warm-season planting, irrigation, succession crops, scouting, beneficial insects, berries, weed control, and recordkeeping.

First: harvest the spring garden while it still tastes like spring.

Cool-season crops do not politely wait around forever. Lettuce, spinach, radishes, kale, and other spring crops can go from tender to tired once heat arrives. May is the time to harvest leafy crops and roots at peak quality, and to notice whether any remaining leafy crops need a light side-dressing of fertilizer to finish strong. Make a record of your favorite cool-season crops now, while the memory of what actually performed well is still fresh. Future You will be grateful. Future You is very forgetful.

Plant the heat lovers, but listen to the soil.

May is prime time for warm-season crops, but the calendar gives a helpful reminder: it is about soil temperatures, not just air temperatures. Peppers and eggplants prefer warmer conditions than tomatoes, so in many parts of Tennessee they can wait until the soil is ready. Seedless watermelons and supersweet corn are especially fussy about cold soils and may germinate poorly if planted too early. UT Extension’s sweet corn guide notes that corn needs a minimum soil temperature of 55°F, while supersweet and shrunken types often prefer about 65°F.

Direct seed cucumbers in Middle Tennessee, and keep okra in mind as soil temperatures rise. Sweet potatoes are often among the last warm-season crops to go in, which is fine because sweet potatoes are not in a hurry to impress anyone in May. They are playing the long game.

Succession planting: because one harvest is nice, but several are better.

May is a good month to keep succession planting going. Continued seeding of corn and beans. Succession planting can also be done with zucchini and cucumbers. With sweet corn, UT Extension recommends planting in blocks of shorter rows rather than one long row because corn is wind-pollinated and needs nearby plants for good ear fill. Sequential seeding with early, midseason, and later cultivars can stretch the harvest window.

Water in transplants and get irrigation settled now.

As warm-season transplants go into the garden, water them in well and give them a starter fertilizer solution to help reduce transplant stress. If you are using black plastic mulch, remember that irrigation must be in place because rain will not move through plastic to the root zone. Drip irrigation is ideal because it keeps water near the roots while helping leaves stay dry, which reduces disease risk.

Natural mulches such as straw can be useful, but May timing matters. Some gardeners wait until soil warms before installing straw mulches because natural mulches can reflect light and slow warming. Organic mulches help reduce weeds, retain moisture, and moderate soil temperatures, while black plastic mulch can warm soil and suppress weeds when installed properly.

Set up supports before the plants start making demands.

Tomatoes, beans, cucumbers, peppers, and other sprawling or fruiting crops are much easier to support before they become a green jungle with opinions. May is the month to set up stakes, cages, trellises, and other support systems at planting or soon after. Waiting until plants are heavy with growth is how gardeners end up wrestling a tomato plant in 88-degree humidity and questioning their life choices.

Take care of berries before the birds find them.

Small fruits need attention in May. Start planning for blueberry fertilization, remembering blueberries prefer ammonium nitrogen sources. Remove weeds from the strawberry canopy to improve airflow, harvest strawberries often, remove damaged berries to lower disease risk, and install bird netting over blueberries and caneberries before the birds decide the crop belongs to them.

Good irrigation is especially important for newly planted fruit crops during the first year. Roots are still establishing, and May weather can swing from “pleasant spring” to “why is the driveway melting?” faster than we would like.

Scout early, scout often, and learn who is helping.

Makes scouting a central task. Check plants at least once or twice a week, inspect the undersides of leaves, look inside the canopy, and use a Z-pattern in larger gardens. Take a hand lens, bags or containers for samples, markers, and a camera. Most importantly, learn the difference between pests and beneficial insects before reaching for a spray bottle.

Beneficial predators include spiders, lacewings, assassin bugs, and lady beetles. Parasitoids, such as certain wasps and flies, control pests by laying eggs in or near pest insects. The beneficial insect guide from Extension specialists notes that protecting beneficial populations can reduce the need for chemical pesticides, and recommends using pesticides only when necessary, planting flowering plants for season-long nectar and pollen, and providing water and shelter.

Weed now, not later.

May weeds are small, optimistic, and still fairly easy to remove. June weeds have joined a gym. Weeds are competitors for water, nutrients, and sunlight, and they can also host insects and diseases. Prevention is the most effective weed control strategy, and cover crops such as buckwheat can reduce weed pressure by quickly forming a thick cover.

Consider buckwheat after danger of frost as a summer annual cover crop or even between rows. It can support pollinators, help suppress weeds, and mobilize phosphorus in the soil. Irises, phlox, columbine, and azaleas are also blooming for pollinators this month.

Spray thoughtfully, not automatically.

May is when preventative sprays for vegetable diseases may need to begin, and fruit crops may need to stay on regular spray schedules. But “preventative” does not mean “panic.” Scout first, identify the problem, protect pollinators, and follow all label directions. UT Extension’s insect control guidance repeatedly emphasizes following the pesticide label, and some recommendations specifically direct gardeners to apply products to flowering plants in early morning or late evening when bees are not present.

May Garden Checklist

Harvest cool-season crops at peak quality.
Record favorite spring crops while you still remember them.
Continue succession seeding corn and beans.
Add succession plantings of zucchini or cucumbers where space allows.
Direct seed cucumbers in Middle Tennessee.
Wait for warm soil before planting peppers, eggplant, seedless watermelon, supersweet corn, and sweet potatoes.
Water in transplants and use starter fertilizer.
Install drip irrigation as warm-season crops go in.
Add stakes, cages, trellises, or other supports early.
Remove weeds from strawberry beds and harvest strawberries often.
Remove damaged strawberries to reduce disease pressure.
Install bird netting over blueberries and caneberries.
Scout once or twice weekly for insects and diseases.
Check undersides of leaves and plant interiors.
Learn to identify beneficial insects before spraying.
Keep common insect and disease resources handy.
Record pest and disease issues.
Stay ahead of weeds before they seed or spread.
Consider buckwheat after frost as a pollinator-friendly summer cover crop.