The danger of frost should now be completely behind us and it should be possible to sow most seeds outside, even if some go into seed trays, modules, or pots for planting out later. If nights are still chilly, and if you’re concerned that temperatures may not be high enough for germination, you can always cover seeds or bring trays and pots indoors.
- Beets: You may have started these in May, but continue sowing beet seeds in June — perhaps a few at the beginning of the month and a few at the end so that in September and October you’ll have some to harvest that haven’t grown too large. They can be stored for the winter if necessary.
- Broccoli: Sow late sprouting broccoli seeds either where you want to grow them or in a seedbed for transplanting later. Depending on the variety and your climate, you should be able to harvest them in autumn or overwinter them for picking early the following year. This late in the year, calabrese is better sown where it is going to stay as it is a crop that doesn’t like being moved once the weather is warm.
- Carrots: This is the last chance to sow maincrop varieties that will be ready for harvesting in September or October.
- Cucumbers – Outdoor cucumbers are usually started off earlier in the year in pots or under cover, but if you sow some seeds outside this month they should give you a crop in August or September.
- Endive – Sow curly or broad-leaved varieties outside for a crop in autumn and early winter. Germination may be erratic in hot weather.
- Herbs – June may be your last chance to sow seeds of herbs such as coriander, basel, chervil fennel, dill, and parsley before the weather becomes too warm for them to germinate reliably.
- Peas – The beginning of June is probably your last chance to sow maincrop peas, snow peas, and snap peas. Toward the end of the month, switch to a fast-maturing early variety. These will be ready for harvesting in about September.
- Pumpkins and winter squashes – These are usually started off earlier in the year in pots, but they can be planted straight into the ground in June. Prepare the soil by adding lots of well-rotted compost or manure.
- Radishes – Sow a few salad radishes in small quantities throughout the month for a constantly replenishing crop.
- Zucchini and summer squashes – If you don’t already have plants you’ve raised in pots, you can sow seeds directly outside now that the soil has warmed up thoroughly. Sow two seeds together and, once they’ve germinated, remove the weaker of the two. Make sure you leave plenty of space between plants because they spread widely and need a lot of room.
Some additional veggies that can be sown in June: Kale, Kohlrabi, Runner Beans, Rutabagas, Scallions, and Turnips.