Unless you live in a tropical environment, the thought of growing vegetables as perennials may seem unlikely. But left to their own devices, many vegetables are self-sowing, allowing you more time plan and plant the rest of the garden.
Lettuce: Even if you live in the far north, you can grow lettuce as a perennial crop. Plant lettuce as usual in year one. Harvest and enjoy throughout the season, but let some of the plants go to seed and then die before pulling. Basically, the wind does the sowing. Mulch over the winter months for an early crop next spring. Leaf lettuces will self-sow more readily than head lettuce.
Spinach: Like lettuce, spinach is a cold weather crop that lends itself to self-sowing. The top photo was taken early this spring, when I had both leaf lettuce and spinach from self-sowing. The bottom photo was taken today. The lettuce is long gone, but the spinach is now completely gone to seed.
Leeks: I used to plant leeks every year. Then one autumn, I was lazy and didn’t pull the plants before they developed seed heads. The next spring I had a new crop of tender leeks. After a few mild winters, my leek bed is now a combination of fresh little leeks, larger mature leeks, and leeks gone to seed – all year long. I haven’t intentionally planted leeks for four years, but have a constant supply anyway!
Borage: Borage is a useful herb whose cucumber flavored leaves can be added to salads and blue flowers make an attractive garnish. It also will go to seed quickly, and live outside in a container, rising like a phoenix year after year.
Pumpkins: Leave a few pumpkins in the garden to rot and the next year you will have a whole new patch. Unless you live someplace with a very long growing season, the small, miniature pumpkins are your best options for self-sowing pumpkins.
Depending on your growing season, several other vegetables will self-sow. I have also harvested cherry tomatoes, cucumbers, watercress, dried beans and purslane from self-sowing. Vegetables grown in containers or raised beds seem to be more prolific, probably because it doesn’t take as long for the soil to warm up, thus leading to earlier germination. If you are the type of gardener who works hard to keep your plants in nice, straight rows free from dying plants, self-sowing might not be for you. But if you aren’t dismayed by the occasional lettuce “clump” instead of row, or the sight of a few rotting vegetables over the winter, throw on the mulch and let your garden sow itself!