12 Vegetable seeds you can plant in MayOn May 6, 2021 by Vlad10 min read
You might think planting your vegetable seeds in May might be too late for proper germination, but the warm temperatures in temperate climates, without the risk of overnight frost, make it the perfect time to plant many of the vegetables for your summer and fall garden. The main thing you have to know before starting to work on your garden is to learn the last average frost date for your location. There’s nothing Google can’t tell you. For most of your summer crops, you want to start planting or transplanting only after that date.
The list below will include vegetables from our previous guides where we went over the seeds you can plant in February and March. If you followed our advice back then, your transplants should be all ready to go outside once the last frost date has passed. If you’re just getting started with your garden, don’t worry, we also included a bunch of vegetables that can be sown directly outside in May.
Leafy greens you can plant in May
Not all types of lettuce like warm weather, but at the beginning of May you can plant “summer crisp lettuce”, which does a lot better in higher temperatures, and grows fast enough to avoid the scorching heat. Nevada and Muir are two other varieties that seem to do great in warm temperatures. They best germinate in soil that is around 15-20° C (60-68°F).
Cultivating lettuce is fairly easy as the plant doesn’t require a lot of fertilizing and it grows really fast. It’s best to choose a shaded area for this crop because high temperatures will cause the lettuce plant to bolt (to start producing flowers and seeds), and that will make the leaves bitter. It also thrives in moist soil, so be sure to water it often.
There are two main approaches to growing lettuce: you can either grow it for lettuce heads by transplanting 3-weeks old seedlings 25-30cm (10-11 inches) apart or you can harvest lettuce continuously for baby leaves, in which case you want to sow them about 2cm (1 inch) apart and cover them with ⅛ inches of lightly pressed soil.
As soon as the soil is soft and can be worked easily you can plant cabbage to have it ready to harvest in late summer. For optimal results, it is best to plant your seeds indoors about a month before and transplant them in May. While cabbage seeds need warmer temperatures to germinate, the seedlings they grow are actually frost resistant, so they will even survive a few light touches of frost towards the end of Spring.
Cabbage has to be watered regularly with 1 inch of water every week. To keep the soil moist and cool you can use mulch around your plants, we’re using hay to mulch the cabbage plants in our Ruth Stout influenced approach. Cabbage heads are ready to be harvested 80- 120 days after being planted, depending on the variety you pick.
This is an ideal vegetable to plant in May, because it does well in cool weather as well as in warm weather. The soil has to be clean of weeds and when you’re ready to plant your seeds, dig a trench that is half-inch deep and plant your seeds 2 cm (1 inch) apart. If you want multiple rows, make sure they are about 20-30cm (10-15 inches) apart from each other, so they have plenty of space to grow.
Your spinach will need to be watered every two weeks, and it will be ready to be picked in about 6 weeks. If you pick the leaves gently, without damaging the roots, your plants will keep growing more leaves, up until the weather is too hot and it will go to seed.
Root vegetables you can plant in May
They are some of the healthiest and most used vegetables in every household, with infinite uses. May is not too late to sow or transplant them outdoors in optimal conditions for a successful harvest, but most of them prefer cooler weather.
Like most root vegetables, carrots do not like being transplanted. Sow the seeds directly in the ground outside.
Make sure the soil is loose and free of debris so that your carrots can grow undisturbed. Sprinkle the seeds thinly along the row then close the soil back along to cover the seeds. The seed trenches should be about 1cm deep, with rows spaced 15cm apart. Once your carrot seeds start sprouting make sure to thin them out and give them enough space to grow.
They need plenty of sunshine, 1 inch of water a week, and they do best with a fertilizer that is low in nitrogen, but higher in potassium and phosphate.
This root crop is packed with vitamins and nutrients and they shouldn’t miss being part of your vegetable garden. A summer harvest of beets requires you to plant them at the beginning or middle of May. But we actually grow them throughout the year using the beet cluster planting method we explained before. You can also check out that article for more information on how to grow better beets.
Using the traditional method you want to plant your seeds 1 inch deep and 4 inches apart, so the roots have plenty of room to grow. Use mulch around them to protect them from heat and to keep the soil moist.
Tasty vegetables to plant in May
Melons, squash, and pumpkins love warm weather and thrive as May vegetables. They’re delicious and have a variety of uses in the kitchen, they’re a great source of hydration and vitamins. They are also some of the easiest vegetables to grow overall, no matter where you live or how much of a green thumb you have.
All types of squash, such as zucchini or summer squash have similar needs when planting. It’s best to plant them in middle to late May when the temperature tends to stop fluctuating and remain on the warm side. You can plant them indoors 3-4 weeks before and transplant them when the soil is warm enough, or you can plant them straight outdoors if the weather allows it.
Squash requires warmth and plenty of sun. Depending on how rich your soil is, you can get bigger plants or harvests, but they will grow fairly well in all types of soil. We actually use them as the first crop in our garden expansion process.
They will require regular watering until they establish deeper roots, and during hot summer days when you see their leaves wilting down. Too much water is not good though as it can cause mildew on the leaves, a dreaded but rather common disease for them.
There are many types of melons, but they have about the same needs as squash: warm temperatures, compost, and water. It’s best to start germination indoors and transplant them outdoors starting with the second week of May.
Melons need growing support in the garden, such as a bamboo cane to which they have to be tied regularly. When the flowers show up, you might have to manually pollinate them by identifying the male and female flowers if you’re lacking in local pollinators.
Melons are ready to be picked when small cracks appear on the surface of their skin.
They’re not just fun to carve and use as Halloween decorations, but they also make for some delicious recipes that remind us of fall. The best way is to plant them directly outdoors, just make sure you have enough space. Pumpkins don’t like soaked soil, they prefer being partially out of the sun, and they need room to grow of about 3 feet between them.
Plant your seeds in late May directly in the ground. They need regular watering, and it’s best to do it very early morning before the temperatures get too high. You might have to prune the vines to keep the plant happy and healthy. Your pumpkins will be ready for picking after 70-100 days. When doing so, make sure you don’t cut the stem too short, otherwise they won’t last for long.
The delicious vegetables are fairly easy to grow anytime after the last frost date, May being an excellent month to plant them outdoors, as they need above freezing temperatures to survive.
Bush beans are easier to grow because they don’t require support, while pole beans will require a bit of a hassle either, but they will keep producing after the initial harvesting until the end of autumn. Furthermore, these legumes are one of the best-known nitrogen-fixing plants. Leaving the roots of the beans in the ground after the plants die back will boost the nitrogen levels in your soil next season.
When planting the seeds, do so 1 inch deep and 2-3 inches apart. Pole beans need support that is about 7 ft tall. You can use bamboo poles or panels. It’s best to water them on sunny days, every week.
The middle and end of May is the perfect time to transplant your pepper seedlings outside if you started growing them indoors. Your pepper plants need a lot of sunlight, so don’t space them too close to one another or the fruit might not ripen. However, pepper plants like to “hold hands” with their neighbors, so they should also be close enough to have their outer leaves touch when mature.
Once they start producing they will need to be supported by a stake. You can spread mulch around the plants to keep the roots cool and the peppers growing happily.
Even though it’s debatable, corn is a vegetable, a fruit, and grain all in one, so it’s definitely worth it to put it on our list. Who doesn’t love corn on the cob with butter? Beginning and mid-Mar is the perfect time to start your own corn patch. Plant your seeds in moist soil, 1 inch deep and at least 6 inches apart, because they get pollinated by the wind. Mix in aged compost between planting for optimal result. If you’re planting more rows, make sure they are about 35 inches apart. This year we’re trying to grow our sweetcorn in a three-sisters garden.
They need 1 inch of water every week, so if it doesn’t rain enough in your area help them out. It takes quite a long time in warm weather for the corn to mature, but it will be ready to pick once the tassels turn brown. The best corn for the treat we all love has milky kernels. If you want baby corn for your stir-fry recipes or to can it, all you have to do is harvest them very early.
A type of green onion, this delicious vegetable is one of the best companions for the other crops in your garden. The smell it produces tends to repel many insects and other pests, protecting its “neighbors” from intruders. Their roots don’t take a lot of space, so they won’t bother their companions, making them the perfect crop to scatters through your garden.
They need plenty of sunlight, regular watering without soaking the soil, and mulch to keep the roots moist all the time. They take 60 to 80 days to reach the optimal age for harvesting, starting to when they are about 6 inches tall.
Of course, when it comes to all of these vegetables you have to take into account your climate. If you leave in a different climate zone, let us know in the comments below how does your May planting list look like?
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We (Vlad & Greti) are building a home on a homestead in a rural area of Romania in Western Europe and sharing our story as two passionate gardeners who ditched the city for a simpler, better life.