For big onion bulbs sow seeds mid to late January indoors

Sometimes the only way to get exactly the plants you want is to grow them yourself. This is certainly the case with onions.

Grocery stores and supermarkets usually only sell the most common types of onions. If the store has a good produce department, you’ll find yellow, white and red bulb onions, plus bunches of green onions. For most uses in the kitchen, that is adequate.

Some gardeners and chefs are more adventurous when it comes to flavors and are always on the lookout for more exotic types of onions. Or maybe an heirloom family recipe from the old country demands a special type of onion.

Sometimes you will have luck finding what they want a farmers markets, but usually not when you want them. In which case, the only alternative is to grow them yourself and that means starting them from seed.

You may wonder why someone would go through all the trouble to grow onions from seed when onions can be grown from sets, those small bulbs grown especially for planting in the garden. Sets work great and make onion growing easy. However these are only available for the most common onions and are just sold simply as red, white or yellow onions.

Garden centers sell bunches of small, bare root onion seedlings, sometimes called starts, for transplanting into the garden. It’s a popular way to grow onions. In this case, once again, you are still limited to what the grower is selling. When when was the last time you saw cipollini onion transplants for example?

The more specialized onion varieties are only available from seed and you have no choice but to grow them yourself.

Seeds are available for an extraordinarily wide variety of onions including round globe onions, elongated torpedo onions, flat cipollini, pearl cocktail onions, storage onions, scallions and others. Each variety type has its own flavor spectrum, usage and level of pungency.

Onion varieties grow best under conditions suited for the particular type being grown. Bulb or globe onions are particularly sensitive to daylight hours.

Since in Michigan we have such long days during the summer compared to days in southern states, we have to choose long day varieties otherwise they will never form bulbs. Long day onions begin to form bulbs when the daylight hours lengthen and the temperatures warm up.

Even though an onion plant may be too small, it will still start to bulb up at the same time as larger plants and you will end up with small onion bulbs.

That means we have to get started early so that the plants are as big as we can get them before bulbing time. Now is the time to sow onion seeds indoors so that the plants will be ready to set out into the garden in April or May.

Seedlings grown indoors require a light soil with plenty of drainage and air infiltration. For best results, use a seed starting mix to start your seeds. Never use garden soil dug from the garden no matter how good it looks, it is much too dense and will turn into an inhospitable solid mass indoors.

Place soil mix in a growing container such as a flower pot, seed flat, milk carton or other container. Just make sure it has holes in the bottom to allow excess water to drain away. Alternatively, you could purchase a seed starting kit.

Place the seeds about a half an inch deep. There are several ways to orient the seeds. You can sow them about a quarter of an inch apart apart into rows. Or scatter them evenly over the soil then cover them with three-quarters of an inch of mix. This takes a precise touch, it’s easy to end up with uneven globs of seeds planted too close together and areas of sparsely planted seeds.

Whatever way you choose, lightly pat the down the soil so it makes contact with the seeds.

Another way is to use plant cell packs, placing three or four seeds to a cell depending on the size of the cell.

Place the container in a warm, dark spot. A heat mat will hasten germination and growth. As soon as the seedlings get to be about an inch tall, move them to a cool, sunny spot. Onion seedlings grow best at around 60 degrees F and no warmer than 70 degrees.

Provide plenty of direct sunlight for your plants, a south facing window is best. If you can, add supplemental lighting in the form of a grow lamp.

Bear in mind that it is not good enough that the plants have a nice view of the window, they need to be right up near the window glass so that they are exposed to direct rays of the sun.

Keep the seedlings evenly watered and moist but not waterlogged. Begin fertilizing when the seedlings get to be about two inches tall. Apply a solution of soluble fertilizer as indicated on the fertilizer container every other watering.

Onion seedlings often grow tall and can fall over and get tangled up. Trim them back to about 4 inches in height with a pair of scissors if they begin to get too tall.

If you start your onions now, they will be ready to set out into the garden in April. Onion seedlings are cold hardy and can be set out four to six weeks before the last frost, making them among the very first plants to go into the vegetable garden in the spring.

It won't be long until spring arrives; the vernal equinox is only eight weeks away. By then your onion plants will be well on their way toward being ready to plant outdoors.