What to Plant in May 2026 ▷ US Garden Planting Guide

What to plant in May by USDA hardiness zone

Zone 5–6: last frost is passing — warm-season crops go in

For Zone 5–6 gardeners (upper Midwest, New England, mid-Atlantic highlands, Great Plains), May is the month you have been waiting for. Last frost dates range from early May (Zone 6b) to late May (Zone 5a), and nighttime temperatures finally climb past the 50°F threshold that warm-season crops need to grow. The first half of May is still risky for the most tender crops (melons, basil, okra) but by mid-month most Zone 6 gardens can transplant safely. Zone 5 gardeners should wait until the third week of May or follow their extension service's last-frost recommendations.

Plant outdoors in May (Zone 5–6): tomato, pepper, eggplant and tomatillo transplants (after last frost); cucumber, summer squash, winter squash, pumpkin and melon seeds or transplants (mid-to-late May); bush and pole bean seeds directly in the ground; sweet corn in blocks for pollination; basil transplants (late May only — very tender); and all the summer annual flowers (zinnias, marigolds, cosmos, sunflowers). Keep frost cloth on hand through the first week of June for mountain areas.

Zone 7–8: full warm-season planting month

Zone 7–8 (Mid-Atlantic coast, Pacific Northwest lowlands, much of the Southeast and lower Midwest) treats May as its peak planting month. Last frost is typically well in the past (March to mid-April depending on location), soil is warm and workable, and daytime temperatures are ideal for both transplanting and direct-sowing. The pressure is to get heat-tender crops in before summer heat arrives — once daytime temperatures consistently exceed 90°F in late June, transplant shock becomes harder to recover from.

Plant in May (Zone 7–8): tomato and pepper transplants (if not already in); direct-sow beans, corn, okra, summer squash, cucumbers and watermelon; transplant sweet potato slips; plant dahlia tubers, gladiolus corms and cannas; direct-sow warm-season flowers (zinnias, marigolds, sunflowers); and finish planting heat-tolerant greens like Malabar spinach and amaranth. Cool-season crops (lettuce, peas, spinach) should be harvested soon — they will bolt as May temperatures climb.

Zone 9–11: heat-tolerant crops only

In Zone 9–11 (Florida, Gulf Coast, Southern California, Hawaii, low desert Southwest), May marks the final window to plant before summer heat becomes the dominant factor. Average highs in late May reach the 90s across the region and continue climbing through September. Cool-season crops are done; most standard tomato and pepper varieties will drop flowers at temperatures above 90°F. The key in Zone 9–11 May is choosing heat-adapted varieties and preparing for drought conditions.

Plant in May (Zone 9–11): heat-tolerant tomato varieties (Heatmaster, Solar Fire, Phoenix, Sun Gold cherry); hot peppers (most hot pepper varieties handle heat better than sweet); okra and southern peas (these thrive in heat); sweet potatoes (the ideal Southern summer crop); Malabar spinach and amaranth (heat-tolerant greens); basil and tropical herbs; and heat-loving flowers (zinnias, vinca, pentas, lantana, marigolds, sunflowers). Set up shade cloth for any remaining leafy greens and install drip irrigation if not already in place.

Warm-season vegetables to plant in May

These crops need soil temperatures above 60°F to germinate properly and will rot or stunt if planted in cool, wet soil. Most also require 70°F+ daytime temperatures for active growth. For direct-sown crops, use a soil thermometer at 4 inches deep to confirm soil is warm enough before committing seeds to the ground.

Crop	Direct Sow or Transplant	Days to Harvest	Min. Soil Temp
Tomatoes	Transplant (started indoors 6–8 weeks prior)	60–85 days from transplant	60°F soil, 50°F nights
Peppers	Transplant only	60–90 days from transplant	65°F soil, 55°F nights
Beans (bush)	Direct sow	50–60 days	60°F soil
Cucumbers	Direct sow or transplant	50–70 days	65°F soil
Summer squash / zucchini	Direct sow	45–55 days	65°F soil
Corn (sweet)	Direct sow (in 3–4 row blocks)	65–95 days	60°F soil (super-sweet: 65°F)
Okra	Direct sow (soak seed overnight)	50–65 days	70°F soil (true heat lover)

The single biggest May planting mistake is rushing warm-season seeds into soil that is still cold. A 58°F soil will delay bean germination by 7–10 days and dramatically increase the odds of rot. Wait the extra week — seeds planted into 65°F soil will catch up and surpass seeds planted a week earlier into 55°F soil.

Summer flowers and bulbs to plant in May

May is the peak month for planting the flowers that define the summer garden. Warm-season annual flowers germinate fast in warm soil and produce their first blooms in 6–8 weeks, giving you color from July through October with a single May planting. Summer bulbs (dahlias, gladiolus, cannas) go in the ground once soil temperatures exceed 55–60°F and reward you with dramatic mid-to-late-summer blooms.

Direct-sow warm-season flowers: zinnias (arguably the best cut flower for beginners — fast, prolific, zero pest issues), cosmos (tall airy plants that fill space beautifully), sunflowers (for cut flowers, choose branching varieties like ProCut or Sunrich; for dramatic garden pieces, choose single-stem giants like Mammoth), marigolds (work as companions in the vegetable bed — repel nematodes), nasturtiums (edible leaves and flowers for the salad garden), cleome (tall back-of-border spider flowers that self-seed each year), and tithonia (Mexican sunflower — butterfly magnet).

Plant summer bulbs and tubers: dahlias are the queen of the summer cut-flower garden — plant tubers eye-up, 4–6 inches deep, with stakes already in place (staking after the plant is up damages tubers). Gladiolus corms planted in succession every 2 weeks through June give you cut flowers from July to October. Cannas and elephant ears add tropical drama to summer borders. Begonia tubers thrive in the partial shade where most other summer bulbs struggle.

Succession planting in May: what to sow every 2–3 weeks

Succession planting is the difference between a garden that produces an overwhelming glut of beans for two weeks and one that yields a steady harvest through September. The concept is simple: rather than planting an entire row of a fast-maturing crop at once, plant a shorter section every 2–3 weeks. You extend the harvest window without increasing your garden space.

Best May succession-planting candidates: bush beans (plant a 6-foot row every 2 weeks through July 1 — each row produces for about 3 weeks); summer squash and zucchini (plant 2 plants in early May, then 2 more in mid-June to replace the first planting when squash vine borer hits); cucumbers (one planting in May, another in late June for a fall harvest before frost); lettuce and greens (only in Zone 5–6 where May is still cool enough — plant heat-resistant varieties like Jericho or Nevada every 2 weeks through early June); radishes and baby carrots (Zone 5–6 only — plant every 2 weeks); and cutting flowers (zinnias and cosmos every 3 weeks for continuous bouquets).

May planting table by crop and zone

Crop	Zone 5–6	Zone 7–8	Zone 9–11
Tomatoes (transplant)	Mid-to-late May	Early May	Heat-set varieties only
Peppers (transplant)	Late May	Early-to-mid May	Hot varieties preferred
Beans (direct sow)	Mid-May onwards	All month — succession	Early May (before heat)
Cucumbers (direct sow)	Mid-to-late May	All month	Early May
Corn (direct sow)	Mid-to-late May	All month — succession	Early May
Summer squash	Mid-to-late May	All month	Succession before July
Okra (direct sow)	Late May only	Mid-to-late May	✅ All month
Dahlia tubers	Mid-to-late May	Early May	Already planted in April
Zinnias / Cosmos / Marigolds	Mid-May onwards	All month — succession	All month

How to transplant seedlings successfully in May

May transplanting success hinges on three things: hardening off, timing, and watering. Skip any of them and you will lose 20–50% of your transplants to shock. Do all three well and transplants will grow faster than direct-sown seeds and produce weeks earlier.

Harden off for 7–10 days before transplanting indoor-grown or nursery-bought seedlings. Day 1: 1 hour outside in dappled shade. Days 2–3: 2–3 hours in partial sun. Days 4–5: 4–5 hours in full sun, brought in at night. Days 6–7: full day outside, brought in at night if temperatures below 50°F. Days 8–10: overnight outdoors if no frost risk. Seedlings that skip hardening off show up as sunburned, wilted, stunted plants that never fully recover.

Transplant in the evening or on overcast days. Transplanting into full midday sun is the number one cause of transplant failure. Evening transplanting gives plants 12 hours of mild conditions to re-establish roots before facing harsh daytime sun. Water the transplant hole deeply before placing the plant, and water again immediately after. For tomatoes, plant deep — bury two-thirds of the stem, which will develop additional roots and create a much stronger plant.

Watering and mulching: preparing for summer heat

May is when watering habits matter most. Newly transplanted seedlings have shallow root systems and cannot handle drought stress. Water deeply (until water runs out the bottom of containers or until soil is wet 6 inches down in beds) 2–3 times per week for the first two weeks after transplanting, then taper to 1–2 deep waterings per week as plants establish. Shallow daily watering is the worst pattern — it encourages shallow roots that cannot survive July heat.

Apply mulch 2–3 inches deep around all transplants once the soil has warmed thoroughly (late May in Zone 5–6, earlier elsewhere). Mulching before soil warms up insulates it and delays the warm-season crops you just planted. Good mulches for the vegetable garden: straw (not hay — hay contains weed seeds), shredded leaves, grass clippings from untreated lawns, or compost. Avoid black plastic mulch unless you are in a very cool climate — it overheats soil in Zone 7+ summers. Mulch cuts watering needs in half and suppresses 80% of weeds.

May garden pests to watch for

Warm soil and new transplants attract a predictable set of pests. Scouting every 3–4 days in May catches problems before they explode. Watch for: cutworms (gray caterpillars that cut seedling stems at soil level — protect transplants with a 2-inch collar of cardboard or foil pushed 1 inch into the soil); slugs and snails (feeding on tender new leaves at night — use iron phosphate bait, which is safe around pets); aphids (clustering on new growth — blast off with a hose or spray with insecticidal soap); flea beetles (tiny black jumping beetles that pepper holes in eggplant and brassica leaves — use row cover); and squash vine borer (in Zone 6 and warmer, wraps the stem of summer squash and kills plants suddenly in June — wrap stems with foil at planting time or use resistant varieties like Tromboncino).

In warmer zones, also watch for tomato hornworms (large green caterpillars that can strip a plant overnight — handpick; accept the white cocoons attached to them as parasitic wasps that kill the hornworm naturally) and Colorado potato beetles (yellow-and-black striped beetles on potato and eggplant — handpick egg clusters on leaf undersides). The May garden is healthy when you spend 10 minutes every other day walking it with coffee in hand, looking at plants. Most pest problems are trivial to solve if caught in week one and devastating by week three.

Frequently asked questions about May planting

FAQ: What to Plant in May

What vegetables can I plant in May?

May is the prime planting month for warm-season vegetables across most US hardiness zones. In Zones 5–6, transplant tomatoes, peppers, eggplant, cucumbers and squash outdoors after the last frost (typically mid-to-late May). In Zones 7–8, direct-sow beans, corn, okra, and summer squash while transplanting already-started tomatoes and peppers. In Zones 9–11, focus on heat-tolerant varieties: okra, sweet potatoes, southern peas, Malabar spinach and heat-set tomato varieties. Continue succession planting of lettuce and greens using heat-resistant varieties in warmer zones.

Is May too late to plant tomatoes?

May is actually the ideal time to plant tomato transplants outdoors in most of the US. In Zones 5–6, wait until after your last frost date (check your local extension service) before transplanting — typically mid-to-late May. In Zones 7–8, early May is perfect. In Zones 9–11, May is late but still possible with heat-tolerant varieties like Heatmaster, Solar Fire, or Phoenix. If buying transplants in May, choose stocky plants with thick stems over tall leggy ones — they will establish faster and produce more fruit.

What flowers should I plant in May?

May is the month to plant warm-season annual flowers and summer-blooming bulbs. Direct-sow or transplant: zinnias, marigolds, sunflowers, cosmos, celosia, cleome, impatiens, petunias, begonias and salvia. Plant summer bulbs (dahlias, gladiolus, cannas, calla lilies, elephant ears) once soil is at least 60°F — Zone 5–6 mid-May, Zone 7+ can plant earlier. For cut-flower gardens, sow successions of zinnias and cosmos every 2–3 weeks through June for continuous blooms until frost.

Can I direct-sow seeds in May?

Yes — May is excellent for direct-sowing many warm-season crops once soil temperatures are reliably above 60°F. Direct-sow in May: beans (bush and pole), corn, cucumbers, summer squash, zucchini, winter squash, pumpkins, melons, okra, sunflowers, zinnias, cosmos, nasturtiums, and basil (in Zone 6+). Check soil temperature at 4 inches deep with a soil thermometer before sowing — warm-season crops will rot in cold, wet soil. If your soil is still cool, wait 1–2 weeks rather than risk losing the seed.

What should I do about late frost warnings in May?

Even in May, unexpected late frosts can hit Zone 5–6 gardens through the third week of the month, and mountain areas at higher elevations can see frost into early June. Protect tender transplants by: covering with frost cloth or old bedsheets before sunset on frost-warning nights (remove in the morning); filling one-gallon milk jugs with water to act as heat sinks around the bed; using mini hoop tunnels or row covers over raised beds; and watering the soil well in the evening (wet soil holds heat better than dry). Never cover plants with plastic directly — it transfers cold and burns the foliage where it touches.