Warm up your green thumb in February with onion seeds
Onion rings, French onion soup, a slice of onion on a hamburger; caramelized onions on steaks, meatloaf or sausage; and the list goes on and on. There are so many ways folks like to eat onions. My dad loved onion sandwiches.
Onions can be planted from transplants sold in bunches. They can also be planted from sets (immature bulbs) typically sold in mesh bags. Readily available at local garden centers in either yellow, red or white, transplants and sets can be planted directly into the garden in spring.
Growing onions from seed takes more time and a bit more effort, but there is one main advantage. There is a wider range of varieties available when you buy onion seeds.
Another benefit is they are planted indoors early in February, a time when gardeners are yearning for a way to get their green thumbs dirty.
There are three types of onions: short-day, long-day and day-neutral. Long-day and day-neutral varieties are best for our Zone 5 gardens. Also, check the expiration date on seed packets to be sure you have fresh seed because the germination rate of older seed is drastically reduced.
Sow onion seeds in purchased flats or recycled containers filled with moist seed-starting mix or lightweight soilless potting mix. Just about any kind of pots will work as long as they are deep enough to allow good root growth and have plenty of drainage holes.
Sprinkle seeds on top of moist potting mix, cover them with a thin layer (one-eighth to one-quarter inch) of more moist potting mix, mist with water and gently press the top of the soil to ensure good seed-to-soil contact. If you are planting more than one variety, remember to label pots before covering them with a clear plastic top. A humid environment can also be fashioned with plastic wrap and Popsicle sticks.
Do not place pots under grow lights or water again until seedlings emerge.
Seeds generally germinate in a week or so depending on the temperature of the potting mix. It takes longer in cool soil and occurs faster in warm soil. Placing pots on a seedling heat mat will give germination a jump-start.
Once seedlings emerge, remove the top or plastic wrap and move them under grow lights. Adjust the lights so they hang just above the foliage and raise them up as the plants grow. Thin seedlings so they are at least a couple inches apart.
Keep the potting mix slightly moist as seedlings grow. Fertilize them every other watering, once they are a couple inches tall, with a water-soluble fertilizer mixed at half strength or compost tea. Trim the tops of foliage when the seedlings have grown 4 or 5 inches tall to encourage stocky stems and the best root development. Don't throw these trimmings away. Instead, toss them in your salad.
Care for plants until they are ready to begin the process of hardening off four to six weeks before the last expected frost date.
If may be too early to start those tomato seeds, but we can get onions growing. Spring, and another season of growing, will be here before we know it.
• Diana Stoll is a horticulturist, garden writer and speaker. She blogs at gardenwithdiana.com.