It’s the most wonderful month of the year! May is the epitome of spring and the official start of summer where I’m from. Vegetable planting in May or even just gardening in May is a tradition that everyone takes part in during or after the ‘long weekend’. In Canada we have a long-weekend dedicated to the official kick-off of patio season, warm weather and most of all, summer gardening. Do I sound a little excited?
Here’s a full breakdown of everything you can start planting outside after the last frost date and some tips and tricks you might need before you get started.
This post may contain affiliate links. If you use these links to buy something we may earn a commission. Thanks.
What Is Last Frost Date?
When it comes to gardening, timing is everything — and that’s where understanding your first and last frost dates becomes so important.
Your last frost date marks the average time in the spring, letting you know when it’s usually safe to plant frost-sensitive seeds and transplants without the risk of them getting zapped by a late cold spell.
Your first frost date is just as important but in the fall when temperatures are expected to first hit 32°F (0°C), bringing an end to the growing season for tender plants.
These dates are averages based on historical weather patterns, which means they’re helpful guidelines — but Mother Nature doesn’t always stick to the schedule! That’s why gardeners often add a little buffer time when planning their spring planting. Both frost dates are tied to your hardiness zone, a tool that helps you figure out what plants are most likely to thrive in your specific climate. Knowing your zone and your frost dates gives you a huge head start toward a successful, healthy garden season.
A few years ago, we experienced a late ‘last frost’, two weeks after our zone date. Everything outside died that night, it was tough. It’s so vital to be aware of your current seasons weather before planting outside!
Are Your Garden Beds Ready?
You’ve determined that your zone is ready to start outdoor seeds to garden in may. Are you garden beds ready? If they’re old beds then they need to be cleaned and cleared of debris and weed. Soil needs to be mended and topped up, mulch needs to be applied. There’s a lot of steps involved to ensure your plants beds are the perfect condition for the season. Follow my checklist on prepping your garden beds for spring.
Direct Sowing Seeds
Starting seeds can be as easy as inputting seeds into the dirt and letting nature take care of the rest. But this is our garden, our food, our self-sustaining goals. We can’t just throw seeds down and hope for the best when our winter storage depends on how successful the season is. It needs to be thought out and planned.
Direct sowing seeds is planting seeds directly into your garden soil instead of starting them indoors. This is one of the easiest ways to grow vegetables, even if you’re brand new to gardening. When you’re gardening in May, the soil has usually warmed up enough for many crops to sprout quickly and grow strong, making it the perfect time for vegetable planting in May.
To direct sow successfully, you’ll want to prepare your garden bed by loosening the soil, removing weeds, and adding compost if needed, find details on preparing your garden beds here. Follow the planting depth and spacing instructions on each seed packet — some seeds like to be buried deep, while others need just a light covering of soil. Keep the soil moist (but not soaked) until you see the first tiny sprouts appear.
Crops like beans, corn, cucumbers, squash, carrots, and radishes all thrive when direct sown because they don’t love being transplanted. Plus, sowing seeds right in the garden means your plants will adapt early to outdoor conditions, leading to stronger roots and sturdier plants. With a little patience and care, direct sowing can make vegetable planting in May easy, affordable, and incredibly rewarding.
Pay Attention to Soil Temperature
Just because you’re ready to start gardening in may – doesn’t mean your soil temperature is. Warm-weather crops like tomatoes, peppers, cucumbers, and melons need soil that’s consistently 60–70°F (15-20°C) to germinate and grow well. You can buy an inexpensive soil tester to check!
Harden Off Transplants
If you started plants indoors, don’t just stick them straight into the garden — they need a few days of hardening off (gradually introducing them to sun, wind, and cooler temps) to avoid shock. Typically this lasts a few days. Put them outside in a sunny spot for a few hours then bring them back in. Do this for a few days. Then try putting them outside all day in one spot for a few days. Then they’re ready to transplant.
Alternatively, if you have a greenhouse, placing your plants in there is an easy way to harden them off without the extra work. These extra hardening off steps might seem unnecessary, but it’s key to successfully gardening in may.
Mulch Early
Related to my advice in prepping your spring beds, you can still add more mulch after the seedlings have been transplanted. After the soil warms up a little, adding mulch around your seedlings will help hold moisture, suppress weeds, and keep the roots cool and happy.
Water Smartly
Seedlings and newly transplanted plants need consistent moisture to get established. Water deeply at the base rather than spraying leaves, and try to water in the early morning. Getting the leaves wet can cause fester disease in the plants if the sun doesn’t dry them.
Watch for Pests
While you’re looking forward to being outside and gardening in May, this is also when bugs start waking up too! Check your young plants daily for signs of pests like flea beetles, cabbage worms, and aphids so you can catch problems early.
Succession Planting
Some crops like lettuce, radishes, and spinach grow fast. Plant a new batch every 2–3 weeks so you can keep harvesting fresh vegetables all summer long. Lettuce and spinach doe regrow new leaves if only cut at the base of the stem. However, sometimes they don’t grow back that fast or well, so succession planting for these can be important if you like tons of leafy greens. Radishes need to be entirely ripped out of the ground to be eaten. So succession planting those is key.
Fertilize Carefully
Seedlings don’t need heavy feeding right away. A light application of compost or a gentle, organic 20 20 20 fertilizer once they’re established can give them a boost without overwhelming them. In fact, I wouldn’t recommend fertilizing at all as you do your gardening in May – I would wait until early or mid-June to fertilize any plants.
Vegetable Planting in May
Beans – Direct Sow
Beans are a hardy, protein filled legume that all gardeners have to try growing at least once. They are a staple in the garden, offering crisp pods or hearty seeds for fresh eating or preserving. For a full comprehensive look on how to grow beans – check out our detailed bean growing guide.
- When to Plant: End of May, after risk of last frost ends
- Days to Harvest: 110-50. Depending on variety. If the seed pod is brown, dried up and rattles when shaken. They’re ready to harvest.
Broccoli Rabe (Rapini) – Direct Sow
A leafy green with a bold, slightly bitter flavor, broccoli rabe thrives in cooler weather and is packed with nutrients for hearty spring meals. It’s known in the west as Broccoli Rabe, but commonly referred to as rapini by those in southern European countries like Italy.
- When to Plant: Early May
- Days to Harvest: 65. This plant is also temperature sensitive, so when it’s ready to harvest – harvest asap! It’s a better option than fully grown broccoli (broccoli is one of those seven plants that I will never grow again).
Broccoli (seedlings started indoors 6-8 weeks ago)
While it may be one of those 7 plants I will never ever grow again in my garden, that doesn’t mean you shouldn’t try growing it in yours. If successful it’s a beautiful vegetable. Broccoli loves the cool seasons and rewards you with big, beautiful heads full of flavor, perfect for steaming, roasting, or fresh garden snacking.
- When to Plant: Early May
- Days to Harvest: 65. This plant is also temperature sensitive, so when it’s ready to harvest – harvest asap or it will flower and go to seed. Be very weary of cabbage moths!
Cabbage (seedlings started indoors 6-8 weeks ago)
Again, it may be a difficult plant for me and something I’m never going to grow again, but it could be a very different story for you. Cabbage is great for preserving in fermented sauerkraut and if it’s not successful, it’s great to feed to chickens!
- When to Plant: Early May
- Days to Harvest: 65 days.
Cantaloupe
Sweet and juicy, cantaloupes love the heat and reward your patience with fragrant fruits that are perfect for a refreshing summer treat. As far as fruits go, it’s not one that commonly gets attacked by pests due to it’s hard shell so it’s an easy win fruit for us.
- When to Plant: End of May
- Days to Harvest: 75-85 days depending on the variety.
Cauliflower (seedlings started indoors 6-8 weeks ago)
Known for its creamy texture and versatility, cauliflower thrives in cooler weather and offers a satisfying harvest whether roasted, mashed, or eaten raw. I’ll never grow it again, but depending on your zone it might work better!
- When to Plant: Early May
- Days to Harvest: 90 days depending on the variety.
Corn – Direct Sow
Few sights are as joyful as tall stalks of corn swaying in the breeze, delivering plump, sweet kernels that taste like pure summer. Be weary though, raccoons wait all season long for your corn as as soon as it’s a day or two ready to be pulled, they come in the night and destroy it all.
DBSFarmWilson Tip: Plant squash around the corn as a protection from pests and plant pole beans beside the corn stalks to allow the beans to climb up. This is known as the ‘The Three Sisters’.
- When to Plant: End of May
- Days to Harvest: 80 days – remember to please be weary of the raccoons!!
Cucumbers – Direct Sow
Crisp and refreshing, cucumbers are a warm-weather favorite that’s easy to grow and perfect for slicing, pickling, and snacking right from the vine. Cucumbers are known to die easily from disease, buy disease resistant varieties. Additionally squash bugs love these plants so be careful of those. Try companion planting things like beans with your cucumbers.
- When to Plant: End of May after last frost.
- Days to Harvest: 55-60 days
Peppers (seedlings started indoors 6-8 weeks ago)
Whether you prefer sweet or spicy, peppers come in all shapes, sizes, and colors, adding vibrant beauty and big flavor to your garden and kitchen. In Zone 5B peppers should have been started indoors 6-8 weeks ago. Peppers need to extra time to grow indoors before sowing outdoors because they love heat. The dryer and warmer the weather, the spicer peppers will get. Read all about it in our comprehensive pepper planting guide.
- When to Plant: End of May after last frost.
- Days to Harvest: 70-80 days
Pumpkin – Direct Sow
A fall favorite, pumpkins are fun to grow and come in all sizes, from small baking varieties to giant carving champions – find the full growing guide on how to grow your pumpkin patch here. We puree and freeze in little pucks to use in baking (like my healthy pumpkin oatmeal casserole – delish!). But if you want to save the pumpkin for Halloween then they need to be cured – the process of their outer skin hardening and preserving the internal flesh for a few months, here’s how to cure your pumpkins and other squashes like butternut.
- When to Plant: After last frost.
- Days to Harvest: 100-120 days
Squash – Direct Sow
Both summer and winter squashes are productive and easy to grow, offering endless possibilities from tender zucchini to hearty butternuts. Both squashes take up a lot of space in the garden. Zucchini can be trained and grow upwards using a t-post and some string. However butternuts have long vines like pumpkins and require lots of space. Be weary of this when planning your garden beds this season.
- When to Plant Zucchini: Mid-May
- Days to Harvest Zucchini: 60 days. Continue to harvest zucchinis while still small otherwise they will grow very large and woody.
- When to Plant Butternut After last frost
- Days to Harvest Butternut: 90 days. Same curing process as I mentioned for pumpkins above – find out how to cure here.
Tomatoes (seedlings started indoors 6-8 weeks ago)
Nothing beats the taste of a sun-warmed tomato straight from the vine, and with so many varieties to grow, they’re a garden must-have. We have had almost every possible situation with tomatoes, you can read it all here at: ‘what’s wrong with my tomatoes’, guide. If you’re certain about growing tomatoes this season (I’m excited for you!), here’s a comprehensive guide on how to grow tomatoes from seed, and a seed-saving guide for the fall. Lastly, if you’re wondering if tomatoes are invasive – check out this article to learn more.
- When to Plant: After last frost/end of may
- Days to Harvest: 60-80 days
Watermelon – Direct Sow
Growing watermelon takes patience and plenty of sunshine, but the reward is sweet, juicy fruits that scream summer with every bite. Remember – two weeks before you want to harvest your watermelon – stop watering it! This allows it to get that sweet taste we all crave.
- When to Plant: Mid-may
- Days to Harvest: 80 days
Conclusion
I hope you enjoyed this article on gardening in May. If you did make sure you check out the other growing guides, seed saving guides and our recipes. We are growing our website with more articles all the time, and we invite you to grow with us. If you have any questions about gardening in May or would like to share some of your knowledge with us please leave a comment below. Happy Gardening!
