11 Vegetable Seeds You Can Direct Sow in May

While spring is unpredictable, by mid-May, most of us experience warming days and frost-free nights. May brings ideal planting and growing conditions with its cool nights, sunny days, and moderate moisture for germination and growth.

This month is prime for many gardeners to direct sow vegetables that rely on warm air and soil temperatures, including juicy signatures of summer like melons, cucumbers, and sweet corn.

Direct sowing is the preferred seeding method for the May vegetables on our list. The warm-season growers develop quickly from seed, and, with extensive roots, are sensitive to disturbance at transplanting.

Direct sow these vegetables in their permanent growing location, whether in the ground, raised beds, or containers, for the least risk of root damage. In the coldest growing zones, starting them indoors in soil blocks or biodegradable pots gives them a head start for the short growing season.

Black Beauty Summer Squash

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Black Beauty Summer Squash Seeds

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Mountain Sweet Yellow Watermelon

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Mountain Sweet Yellow Watermelon Seeds

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Honey and Cream Sweet Corn

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Honey and Cream Sweet Corn Seeds

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Zone Tips for Direct Sowing in May

In warm climates, you’re likely well underway with transplanting warm-season crops in May, but the long growing season may warrant late additions and successional rounds. In cool climates, wait until soil temperatures warm to get the best success.

The anticipated final frost date of the season helps determine which vegetables to direct sow in May, as well as when to plant them throughout the month and into June. Growing zones, too, and especially local microclimate, are good guides. In zones 7 and higher, you’re frost-free in May with warm soils and air temperatures ideal for direct sowing heat-loving vegetables.

In zones 5 and 6, look at late in the month and into early June for seeding. With direct sowing, waiting for warm soils is worth it in harvest rewards. Zones 4 and colder, June is best for direct sowing or transplanting those seedlings started indoors.

For vegetables to direct sow in May, we’ll include those to sow one to two weeks after the final frost and a few at two to four weeks after, all depending on your local conditions.

Cantaloupe/Muskmelon

	botanical name Cucumis melo
	sun requirements Full sun
	height 6’ vines

Melons take a relatively long time to develop, soaking up long summer days and sweetening in the rising temperatures. They mature in about 80 days, some taking up to 100, and others slightly earlier, particularly dwarf varieties. As frost-sensitive annual crops, it’s best to wait for soil and air temperatures to warm to the sixties (around 16°C) to direct sow melons.

The melons we call “cantaloupes” are usually muskmelons, with true cantaloupes as smooth, green fruits of European origin. The netted skins of muskmelons, aroma, and orange-pink, sweet flesh are unmistakable.

‘Hearts of Gold’ is a favorite 1800s heirloom muskmelon with deep orange flesh and a tangy sweetness. It has productive and vigorous vines that make it a good selection for cool climates with short growing seasons (and everywhere else).

Another match for direct sowing across climates is the productive heirloom ‘Minnesota Midget’. It bears four-inch muskmelons with densely netted skins and sweet, golden flesh, soft all the way to the rinds. Quick development and disease resistance make for strong yields.

‘Charentais’ is a 1920s French heirloom. The grapefruit-sized melons have smooth skins with mellow orange flesh that tastes like it should be dessert. The perfectly apportioned fruits serve one or two and are harvestable in 90 days.

Sweet Corn

	botanical name Zea mays
	sun requirements Full sun
	height 5-12’

Sweet corn is the most popular “eating” type for its high sugars and juicy kernels. Depending on the variety and sugar content, the sweetness ranges in intensity. 

In warm weather, sweet corn grows quickly from seed. In cool climates, look for an early-maturing variety like ‘Golden Bantam,’ which tolerates cool spring soils. The 1902 heirloom has sweet, yellow kernels and two sturdy ears per stalk.

Colorful additions include ‘Ambrosia’ with white and yellow kernels and supreme flavor, and ‘Martian Jewels’ with pale white kernels against purple husks and cobs. Direct sow corn one to two weeks after the final frost and as soil temperatures rise above 60°F (16°C). Sow successional rounds every few weeks for harvests throughout the season. Corn needs regular water and fertile, well-drained soils to thrive.

Cucumber

	botanical name Cucumis sativus
	sun requirements Full sun
	height 3-6’

Cool, crisp cucumbers are a delight in summer. Direct sow the vegetables in May to minimize root disturbance, seeding them one to two weeks after the last frost and when soils warm to 60℉ or more. The warmer the weather, the better for these heat lovers, even up to 90°F (32°C).

Opt for heirloom cucumbers to bring strong performance and culinary history to the garden and plate. ‘White Wonder’ is a 1893 fast-growing and heat-tolerant heirloom that starts a bright, pale green and matures to ivory white. ‘Lemon’ from 1894 bears round, lemon-sized fruits in sunny yellow with a light flavor. Burpless and not bitter, you can eat these like an apple off the stem or use them for fresh slicing or pickling.

Dwarf varieties are versatile in their space-saving for pots or beds. They produce sizeable yields on their compact vines. ‘Spacemaster 80’ yields full-size slicers from short vines.

Zucchini

	botanical name Cucurbita pepo
	sun requirements Full sun
	height 2-12’

Summer squashes, like zucchini and pattypan, produce quickly and easily from seed. Bushing varieties take less time to develop mature fruits than many of the long, vining types, but either are a fit to direct sow this month. Opt for bushing types if your summer growing season is short, or you want to install a successional planting later in the season.

‘Black Beauty’ is a favorite 1920s introduction with a bushy habit and prolific yield. Dark, greenish-black fruits have tender and creamy white interiors. The All-America Selections award winner has early, flavorful fruits on an easy-to-grow form.

Direct sow zucchini and other summer squashes in warming soils, ideally 70-85°F (21-29°C). Enjoy them as full-sized fruits at six to eight inches long or harvest them early as tender baby vegetables.

Bush Beans

	botanical name Phaseolus vulgaris
	sun requirements Full sun
	height 2-3’

Bush beans tolerate cool-to-warm fluctuations and are fast-maturing, ready in about 50 days. With a delicate root system, they’re best direct-sown and thinned to ensure adequate spacing. Beans need good air circulation around leaves and stems to stave off fungal issues.

French green beans like ‘Maxibel Filet’ are long, slim, and tender. The full-length lean beans are stringless and grow six to eight inches. ‘Contender’ is another favorite stringless that tolerates heat and resists diseases like powdery mildew.

Bush beans thrive in mild summers with temperatures below 90°F (32°C). Sow successive rounds every week or two to continue the harvest. In hot climates, sow in spring or fall.

Butternut Squash

	botanical name Cucurbita moschata
	sun requirements Full sun
	height 15’ vines

Winter squashes, like butternut, acorn, and pumpkin, take a long time to develop their weighty fruits with thick rinds. Direct sow these vegetables in May to harvest in late summer and fall. Easy to grow from seed, plant squash one to two weeks after the final frost, and when soil temperatures warm above 70°F (21°C). In areas with short growing seasons only, try starting them indoors in biodegradable pots or soil blocks to allow time for development.

‘Honeynut’ is a dwarf moschata selection with good squash vine borer and powdery mildew resistance. C. moschata is more resistant to squash vine borer (SVB) infestations than other species with thick, smooth skins. ‘Honeynut’ is a hybrid out of Cornell with small fruits at four to five inches long. They start mottled green and ripen to mellow orange-red. 

These butternuts store for up to six months with a sweet flavor and creamy texture. Short, bushy vines grow well vertically.

Okra

	botanical name Abelmoschus esculentus
	sun requirements Full sun
	height 4-5’

Okra is durable, flourishing in the summer heat of southern climates. It’s also ornamental with small, hibiscus flowers, palmate leaves, and striking seed pods. Enjoy young pods fresh, cooked, or pickled, or freeze them for winter vegetable soups.

‘Clemson Spineless’ is a 1939 introduction built off of years of hybridizing in South Carolina. The ribbed, velvety green pods are spineless. Harvest them when they’re five inches or smaller for the best texture. The pods grow impressively long but become tough and sinewy.

Okra grows best in warm-to-hot conditions, and germination is highest when soil temperatures are 70°F (21°C) and above. The heritage crop tolerates various soil types but prefers sandy loams with good drainage.

Eggplant

	botanical name Solanum melongena
	sun requirements Full sun
	height 2-6’

Eggplants do well started indoors from seed, but direct sowing means there’s no need for seed-starting materials, long oversight of seedlings, or taking up precious indoor space. They’re best sown about two to four weeks after frost with soil temperatures at 70°F (21°C) and higher. Wait until nighttime air temperatures are above 60°F (16°C).

‘Black Beauty’ is a longtime favorite for its compact growth, large fruits, and delicate flavor. The shiny, dark purple eggplants have thin skins that don’t need peeling. ‘Long Purple’ is a Japanese variety with long, slender fruits. The delicate flavor is milder than other types.

Pumpkin

	botanical name Cucurbita pepo ‘Jack Be Little’
	sun requirements Full sun
	height 3-5’ vines

Pumpkin is a winter squash, perfect for planting in the spring to harvest closer to autumn. ‘Rouge Vif d’Étampes’ is the famous ‘Cinderella’ pumpkin. The seasonal favorite in melon-orange is from 1880s Paris and is the inspiration for the fairytale princess’s cucurbit carriage. The large rounds reach one to two feet in diameter and may weigh 15 to 20 pounds each. 

The bumpy ‘Galeux d’Eysines’ brings character in buff peach with textured skins. Sugars crystallize under the skin and results in raised areas. The French heirloom has a high sugar content and a sweet flavor. The 12-inch diameter rounds weigh 10 to 15 pounds. 

Watermelon

	botanical name Citrullus lanatus
	sun requirements Full sun
	height 6-10’ vines

Watermelons join other cucurbits in favoring direct sowing over transplanting, which may damage roots. Sow in warm soils between 70-90°F (21-32°C).

‘Sweet Mountain Yellow’ brings classically large 20 to 35-pound fruits with dark and light green-striped rinds and yellow flesh. Not only is the color novel, but the flesh is deliciously sweet and juicy. The high sugar content and firm texture make the harvest worth the wait (95 to 100 days to maturity).

‘Sugar Baby’ is sweet and delicious and small enough to fit in an icebox. It packs juicy flavor in a compact form with firm, dark skin. At six to ten pounds, the little rounds develop faster than full-sized varieties. ‘Sugar Baby’ is an improved dwarf variety with deep red flesh and mottled black-green skin.

‘Luffa’ Gourd

	botanical name Luffa aegyptiaca
	sun requirements Full sun to partial shade
	height 20’ vines

Luffa (also “loofah”) is a fun one to direct sow in May for its spongy uses later in the season. The vines produce one to two-foot-long green fruits with a dense, fibrous interior. By peeling the skins, the interior fibers become useful as scrubbers for the bath and kitchen.