The Overwintered Garden

“Overwintered” is a term used to describe a vegetable that is planted in the spring, summer or fall of one year in order to be eaten in the spring of the following year. This is a great way to extend the growing and eating season in our Vermont climate. Overwintered crops generally are dormant all winter long and then come back to life with the lengthening days and warming temperatures of spring.

Overwintered Spinach - Not all vegetables can survive our VT winters, but the few that can include spinach, parsnips, leeks, garlic, and parsley. Spinach for early spring eating (mid to late April) should be sown in the first two weeks of September. Once it germinates, allow it to grow without harvesting or touching it. You can eat a little if you want, but ideally you will leave as much of the plant in the ground as possible. Once very cold weather hits, in early to mid-December, you can protect the spinach under a layer of straw, or leaves, or a few layers of thick row cover (Reemay or Agribon can be found at Gardeners’ Supply Company or ordered online at Johnny’s Selected Seeds). In the early spring, as soon as the ground has thawed out, remove the layers of protection and you will see the spinach slowly coming to life, long before any other plants begin to stir. It won’t look like much at first, but will quickly grow to be the size of spinach planted during normal times. It will be extra sweet from having survived the cold and will be incredibly rewarding - a truly vibrant food. This is such a delicious treat for early spring and really worth the trouble.

Overwintered Parsnips- parsnips are a long season crop. They are best when planted in very early spring and harvest the following year. This allows them to grow to a good size and then sweeten up with the cold temperatures. Plant the strange looking seeds in shallow trenches, ¼ inch deep (that is NOT very deep!). Keep well watered and well weeded all summer long. In the fall, you can harvest a few of the larger parsnips to eat September through December, but be sure to elave a few for spring time meals. Once the ground is frozen, in later December, mulch heavily with a layer of straw. The straw moderates the soil temperatures and prevents the soil from buckling and heaving with the freeze and thaw cycles. Pull off all of the mulch as soon as the ground thaws, and then in late April and early May, you can dig up huge, sweet roots that are a lovely addition to spring time soups, roasted vegetable dishes and purees.

Leeks are another crop that is planted very early in spring - mid to late April is ideal. The small and slender plants are planted in trenches, about 6 to 8 inches apart in rows that are 12 inches apart. Keep leeks well watered and weeded. Once they are about 10” tall, you can fertilize them with a good organic fertilizer such as Pro Gro from North Country Organics or Compost Plus from Vermont Compost Company. Then hill up the plants with soil from in between the rows. A good hoe makes this job much easier. The more you hill, the larger the plants will be. This allows for more of the white, edible portion to grow. Hilling also helps to keep the moisture even, another condition which encourages bigger growth. You can hill leeks one more time before fall, in early August or so if you choose to. If you cannot eat all of your leeks in the fall, leave a few in the garden for overwintering. Mulch well with straw (about 6” in depth) and let sit in the garden all winter long. On warmer winter days, you may be able to still harvest some of the leeks if the ground has not frozen solid under the mulch. With whatever leeks are left in the ground come snow melt, pull off the mulch and wait to see what happens. Not all leeks will have successfully lived through the winer, but about 40 to 60% should if you have followed these steps. You will see some yellow and rotting foliage with fresh green growth poking through. These are the leeks that have made it through winter. Let them size up a bit before harvesting. They will come back to life and can be picked and eaten in later April or mid-May. You will have to peel back some of the outer layers, but underneath will be a luscious, silky treat. So sweet in spring, and a great addition to soups, vegetable tarts, or braised meats.

Other crops: I have had good luck with late seedings of lettuce, scallions, cilantro and dill. These all overwintered fine and were good for a few salads in very early spring before they decided to go to seed. The lettuce varieties that I have found to be most well adapted to overwintering are Merveilles des Quatres Saisons, a beautiful French heirloom variety,  and Tango, a green oakleaf. You can also plant shallots and garlic in fall for early harvests. Green garlic is an immature head of garlic that tastes milder than its full grown version.  Parsley is a biennial and will also come back to life in the spring before it goes to seed. Biennials make a flower in their second year, so this is normal plant behavior! Remember, every winter is different. This type of growing requires flexibility, observation, and a willingness to experiment. Exact planting and harvest dates are not easily determined because they are a function of weather, where you garden is sited, and micro climates. The best way to understand overwintering is to start doing it, and see what works well for you. Observe each crops natural life cycle, and learn to work with it in the context of our long and cold winters. There is no better way to say “Hello, Spring!” than by harvesting your first salads in April when green life is just beginning to stir.