One of the easiest and most rewarding gardening projects you can undertake right now is gearing up to grow parsley through winter. There are two ways to go about it. You can grow a few plants indoors and enjoy non-stop production of fresh sprigs all winter. Or, plant young parsley seedlings outdoors or in a cool greenhouse, and look forward to a flush of spring leaves followed by edible flowers in late spring that are much loved by beneficial insects. Next come so many aromatic seeds that you may never need to buy parsley seeds again. To make the most of this bountiful biennial, grow parsley through winter both ways.
Starting Parsley Seeds
Your first step will be to start some parsley seeds. Mail-order seed companies won’t be fully restocked on parsley seeds until spring, but most have at least a few varieties on offer. When choosing a variety to grow as a reseeding biennial, I favour curly varieties like good old ‘Moss Curled’, which has been gracing gardens since before 1865.
Parsley seeds germinate faster under warm summer conditions compared to spring, but they still should be primed by putting them in a strainer and dousing them thoroughly with hot water. This step rids the seed coats of germination inhibitors, so you can expect seedlings within 7 to 10 days. I grow my winter parsley seedlings outdoors in the shade until they have two true leaves, and then transplant them to larger containers, one or two to a pot, depending on the container’s size. Contrary to garden lore, parsley seedlings are not difficult to transplant provided the roots are well dampened before the move.
Growing Parsley Indoors in Winter
In the photo above, taken in early March, I counted 78 stem stubs on the two parsley plants that grew in a sunny south window last winter. That’s a lot of fresh picked parsley, enough so that I didn’t need all of the parsley I had dried. These were seedlings started in August and brought indoors in October. If you don’t have a sunny south window, you can grow parsley indoors under fluorescent or LED lights, at least while the plants are small. Once they become bushy, it’s more difficult for overhead lighting to penetrate the leaves, so the plants are better off on a cool windowsill, turned every day or two so they receive even light on all sides.
Tiny, wedge-shaped aphids can become a problem when growing parsley indoors. Take infested plants outside on a mild day, and hold them sideways while you wash away aphids with slightly soapy water applied with a pump spray bottle. Repeat every few days until the aphids are (hopefully) under control. Should you live in areas where convergent ladybirds come indoors in winter, you also can catch a few of these unwanted houseguests, release them on aphid-ridden plants, and watch the miracle. The aphids will be gone in a week.
Growing Parsley Outdoors in Winter
Well-rooted young parsley plants equipped with an insulating surface mulch are hardy to about 10°F (-12°C), but leaf quality suffers at temperatures below 20°F (-6°C). In marginal climates or covered beds, focus on getting the roots and growing crowns through winter. To reduce repeated freezing and thawing, cover mulched plants with a shroud made of row cover or an old sheet. In addition to buffering cold winds, the cover will protect the plants from rabbits, deer, and other hungry animals. When uncovered in early spring, the plants will quickly grow away.
As true biennials, parsley plants must get nicely chilled if they are to produce scads of little flowers for hover flies and other small beneficial insects, followed by a nice crop of seeds. In my climate, parsley plants that bloom early set the best seed crops, especially if the tall stems are staked to keep them off the ground. On a dry day in early fall, I collect ripe seed heads in a paper bag, and let plenty more fall to the ground. In good years, there will be legions of volunteer seedlings the following spring, and I’ll have plenty of saved parsley seeds for sharing, replanting, and even eating. Parsley seeds can be used in place of celery seeds in cooking, though it’s best to soak them in water overnight to plump them up first. Lacy parsley flowers make a lovely edible garnish.