Hands-On Gardener: Time to Start the Onions, Celery and Parsley!

by Miriam Hansen

Today I sprinkled last year’s onion seeds onto wet paper towels, marked the variety and date and slipped them into individual Ziploc bags. I’ll start checking for germination in a couple of days and every day thereafter. Last year I forgot about them for a week. By the time I checked, their growing tips had threaded through the paper towels. I managed to tease most of them free without too much breakage, but then I compounded the error by planting them upside down, mistaking the growing tip for the root!

While February is the month to plant onions, celery, parsley and celeriac, early March is the month to plant anything that says “Indoor Germination: 8–10 weeks before transplanting outdoors in spring.” This includes many perennial and annual flower seeds.

There are three principal things to consider when you are starting seeds: the medium you use, the container you fill with that medium and the way you treat the seeds you are planting. Since I’m starting a huge number of seedlings, I generally buy a bale of Pro-Mix or some equivalent medium. I have splurged and bought a bag of Vermont Compost Company’s Fort Vee for my onions and shallots, one of the very few long-growing seedlings I do not transplant.

Your rule of thumb is to use a growing medium that is sterile, retains moisture and has enough nutrients to get your seedlings started. You will eventually need to fertilize, particularly if as is the case with onions, you are going to leave those seedlings in their original medium to grow in. Most of the seedlings I grow do eventually get transplanted. At that point, I will often mix in some soil or compost since I am no longer concerned with damping off or any of the other fungal diseases that can affect delicate seedlings. There are many different fertilizer regimens. I use a slurry of worm castings, but if you don’t have worms, watering every two to three weeks with dilute solutions of liquid kelp and fish emulsion is a good regimen. As long as the leaves are a deep green and your plants are stocky, you don’t need to worry that they are not receiving enough fertilizer.

If you are looking at gardening centers and catalogs, you can get overwhelmed by the choices of containers. My attitude is to go with what is cheap and durable. All you are looking for is something to hold the medium, retain moisture and encourage healthy root development. A friend did some experiments last year with paper cups, peat pots and plastic pots and found that plastic was hands down the best material in terms of seedling growth and health.

You also want to suit your container to the crop. The cucumber family prefers not to be handled. I start those in late April or May in four-inch plastic pots and leave them until they are ready to set out. Others, like tomatoes, peppers and the Brassica family, will grow pretty quickly and need some depth and enough room to grow as seedlings before you transplant them. Many of the flowers I’m seeding start out really tiny and are slow growers. I sow them in shallow flats and eventually prick them out (a fancy word for transplanting tiny seedlings) into individual plastic six or eight packs.

Regardless of what container you use, make sure there is drainage! For years I’ve sowed onions in shallow trays that are actually meant to hold six packs and therefore have no drainage holes. I make X-shaped slits in the bottom and then line the trays with plastic into which I’ve poked holes. Offsetting the drainage holes in this way seems to keep them nice and moist for the three months they’ll be growing in there.

When you’ve seeded your trays or pots, cover them with plastic. I use grocery bags slipped over each side of the tray. When the seeds germinate, take the bags off. Over the years I’ve learned that it is penny-wise and pound-foolish to start different kinds of vegetables in the same container. Even seeds of the same kind and variety of vegetable will germinate at different rates, but when you combine, for example, tomatoes and peppers or cabbage and cauliflower, you just complicate things unnecessarily.

Seed treatment can vary from overnight soaking (highly recommended for parsley and celery) to scarification (nicking the hard seed coat) to freezing and chilling. Usually the seed packet will give you recommendations for this as well as the best temperature and conditions for germination. Some seeds like to be cool (lettuce) and some like warmth (tomatoes and peppers).

Gardeners tend to have their own ideas about timing when it comes to seedlings, learning from experience what works best for them. I will say this. I tend to jump the gun, starting everything a bit too early and then having to juggle like mad to find space under lights, in cold frames and greenhouses, covering plants set out a bit too early and so on. I make no apologies. That is how I roll. Whichever way you roll, don’t panic. If your tomato seedlings are leggy and look bedraggled because you started them in early April instead of mid-April, they will still produce like crazy. And if you waited a bit too long and your plants are tiny when you set them out, they will also produce like crazy. Nature is amazingly forgiving.

Happy gardening!

Miriam and her husband, David, live in East Montpelier, where they grow most of their own vegetables, berries and meat on less than one-quarter of an acre. Your questions and comments are welcome. You can reach Miriam at freshair460@gmail.com.