May - this is what you can cultivate
Finally! Sun, warmth, and budding sprouts. Now spring is truly here, and you can sow plenty of greens directly into pots and beds. If you want to harvest a lot this summer, you should get as much as possible in the ground now.

SOWING CALENDAR – MAY
When the frost recedes and the soil settles, it's time to sow plenty of flowers and vegetables. This is also the time to plant sets of onions and potatoes, which can be harvested later. Carrots, lettuce, beets, and many other crops can now be sown outdoors without having to pre-cultivate the seeds indoors first. And much of what you've pre-cultivated indoors can now be planted outside. But wait another month or two before planting the most frost-sensitive plants, such as melons, peppers, and chili.
Keep in mind that the timing for when plants should be planted outdoors varies depending on your hardiness zone, and always take the weather into account—there could still be the occasional frost night or two.
When it's time to plant, remember that young, small plants that have grown indoors—even the hardiest ones—need to be gradually acclimatized to the outdoor environment. This is called hardening off. It's a good idea to use a row cover at first to protect the plants and create more stable temperatures.
Plants you can sow outdoors in May
- Spinach
- Beets and other types of beets
- Carrots
- Chives
- Beans
You can sow bean seeds now, but wait a little longer before planting out the seedlings. - Peas
- Potatoes
- Set potatoes
Opt for heat-treated seed potatoes to increase the chances of a large harvest. - Lettuce
- Dahlia
At the end of May or beginning of June, when the risk of night frost has definitely passed, it’s time to plant out the pre-cultivated dahlias. If you’re unsure about the weather, wait a bit longer! Dahlias are very sensitive to frost. - Summer flowers
For example, nasturtiums, zinnias, corn poppies, ornamental basket flowers, and summer rose mallows.
See our vegetable seeds and flower seeds.
Plant out pre-cultivated plants
If you have pre-cultivated plants indoors, you can plant out the hardiest ones after hardening them off. Hardening off means gradually acclimating the plants to outdoor life by leaving them outside only during the daytime for about a week before planting them out permanently.
However, most plants that have been pre-cultivated indoors will need to wait a bit longer before they can be planted outside. The plants that need the most warmth, such as beans, cucumbers, and squash, must stay indoors the longest – until summer has fully arrived with its 20-degree temperatures.
Pre-cultivate inside
It’s often a good idea to pre-cultivate plants that snails are fond of. The plants have a better chance of staying safe from snails if they are planted out as larger plants, rather than when they emerge from the ground small and fragile.
If you continuously pre-cultivate lettuce and other leafy greens, you’ll also have new small plants to plant out as you harvest and make room in your beds and plant boxes outside.
If you want to grow fragrant sweet peas, May is the month to get started.

Swedish garden inspirer, journalist and author of books about nature, cultivation and animals, such as "Soil", "Grow for insects" and "Chickens as a hobby".
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