Grow large gourmet onions by starting onion plants indoors in January
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Grow large gourmet onions by starting onion plants indoors in January

Oct 21, 2023

Onions are the most common produce staple found in kitchens around the world. They are used in virtually all cuisines in a wide array of recipes.

Most home cooks are only familiar with the few basic onion types found in the produce section of their supermarket. For the so-called dry onions, usually the round yellow, round white and occasionally red onions are all that are available. Green onions or scallions are available sometimes.

More uncommon types of onions can be found at specialty grocers and farmers markets.

If you want even more options, there are all kinds of gourmet onions out there. Most of the time you can only get those specialty varieties if you grow them yourself. For the most part, that involves growing them from seed.

The secrete to growing onions from seed is to get started early. I try to sow my onion seeds indoors sometime during January. However, you can still plant onion seeds in February and get adequate results.

That means if you don't have onion seeds, now's the time to research the varieties and place your order with your favorite seed sellers. For example: Gurney's has a variety called "Red Candy Apple"; Jung's sells Salad Bunching onions; Shumway Seeds offers "Red Torpedo" onions; Johnny's Selected Seeds has a huge selection of onions including shallots.

Green onions and scallions, sometimes classified as bunching onions, are grown the same way as bulb onions.

When shopping for seeds, stay away from intermediate and short-day varieties, as they are not adapted to our Michigan latitude. Other than that, most varieties do well in our area.

Onion seedlings are fairly easy to grow. Compared to many vegetables such as tomatoes, peppers and others, onions don't require as much attention.

With most other vegetable seedlings, transplanting crowded seedlings from their starting container into individual pots or cells is absolutely necessary. That's not so critical with onions. They do quite well growing close together like a clump of grass during the early stage of their life cycle.

For sowing onion seeds, I use 6-inch plastic flower pots. They're easy to wash and sterilize and can be used year after year. Plus, as a bonus, reusing pots reduces the amount of plastics going to the landfill.

Fill your growing container up to an inch or so from the top with a good seed starting mix. Other types of potting mixes may be used if starting mix is not available.

Gently press the soil down, don't crush it down too much, though, and moisten it.

Sprinkle your onion seeds evenly over the surface of the soil, about 50 -60 seeds will fit nicely in a 6-inch pot. That's a lot of onions for most home gardens.

Cover the seeds with about a quarter-inch of the starting mix and firm the soil mix down so it makes good contact with the seeds. Gently and lightly water the pot.

You should start to see the tiny seedlings begin to emerge in about a week to 10 days at 70 degrees. Once they've emerged, place the pot in a sunny area. If possible, drop the growing temperature to the lower 60s during the day and upper 50s during the night for best growth. Keep them moist but not soaking wet.

If you grow your seedlings under artificial light only, give them 10 hours of light a day.

Onion seedlings are light feeders, meaning they don't need much fertilizer to grow. The nutrients present in the planting mix will usually keep them going for two or three weeks after germination. After that, fertilize your growing plants with a water-soluble fertilizer once a week or so.

When growing indoors, onion seedlings will grow so much that they will fall over. Before that happens, cut back the tops to about 4 inches with a pair of scissors.

Onion transplants can tolerate frost and cold soil temperatures. If your plants are started now, they’ll be big enough to plant them into the ground as early as April. That will give them plenty of time to grow.

Long day varieties begin to form bulbs when the daylight time reaches 14 hours of daylight. The larger the onion plant is when it begins to form bulbs, the larger the onion bulb will be.

When planting time rolls around, you just knock the plants out of the pot all together in one clump and pull them apart as you plant.

Onions can also be grown from little onion bulbs, called sets. However these are only available in limited varieties. I have to confess, though, I've used them plenty of times in the past during those years when I was not able to grow my own transplants.

Not only do homegrown onions in general taste better, you can pick and choose the variety you want without having to depend on what the local garden center has to offer.

Sowing onion seeds marks the beginning of the gardening season for many gardeners.