When I plant in my garden or landscape I like to know what I am planting. A tomato isn’t just a tomato, and an onion isn’t just any old onion. Going a bit further, planting the cherry pit or peach pit from the fruit you have just eaten may sound like a great idea but you really just don’t know what variety it was — or even if it was cold hardy for Harvey County.
I just have to know what I am planting for sure. It can be difficult to find specific onion varieties in sets or transplants by variety name, so growing from seed may be a preferred option. Onions are one of the first plants to be seeded for transplanting because this crop takes a significant amount of time (six to eight weeks) to reach transplant size and because they can be set out relatively early (late March in much of eastern and central Kansas). Therefore, we want to start onions in mid- to late-January. Onion seed should be placed ½ to 3/4 inch apart in a pot or flat filled with a seed starting mix.
Place the container in a warm (75 to 80 degrees) location until young seedlings emerge. Move to a cooler location (60 to 65 degrees) when the seedlings are 1 to 2 inches tall. Make sure they have plenty of light, using florescent lights if needed. Start fertilizing when the seedlings reach 2 to 3 inches tall using a soluble fertilizer with each or every other watering.
Onion seedlings tend to be spindly with the remains of the seed sticking to the end of a leaf for several weeks. Encourage stockiness by trimming the ends of the leaves when the plants reach 4 to 5 inches tall. Start hardening off the onions in early March by moving the plants to a protected outdoor location. You may have to move them inside temporarily to protect them from extreme cold snaps.
Planting in the winter is fun!
— Scott Eckert is a Kansas State Research and Extension agent for Harvey County. Horticulture is his specialty. The Harvey County Extension office can be contacted at 284-6930.