Tips for successfully starting seeds at home

Starting plants from seed can make vegetable gardening both less expensive and more interesting. “You can buy seeds for a much wider range of plant varieties than garden centers sell as transplants,” said Spencer Campbell, manager of the Plant Clinic at The Morton Arboretum in Lisle. “And a packet of 30 or 40 seeds often costs less than a single seedling in a pot.” Advertisement When you’re planning your vegetable garden in January, think about which plants you’ll want to grow from seed and begin seeking out the right varieties through websites and catalogs or by swapping seeds with other gardeners.

The Arboretum will hold a seed swap on Jan. 27, as well as a hands on workshop, Starting Vegetables from Seed. Learn more at mortonarb.org/gardening classes . As you plan to start seeds, read seed packets carefully for important information about how many plants you will need and how and when to sow the seeds.

(Beth Botts / The Morton Arboretum) Here are some tips from the Plant Clinic for starting seeds at home: Advertisement Provide light. New seedlings need light about 16 hours a day. Many gardeners set up LED or fluorescent lights a few inches above the plant pots. If you’re trying seed starting for the first time with just a few seeds, a sunny south or east facing window may work.

Prepare containers carefully. If you plan to use recycled containers such as yogurt cups or cut off milk jugs, be sure they are very clean. Sterilize them in a solution of 1 part bleach to 9 parts water. Punch several holes in the bottom of each pot so water can drain away. Or purchase plastic or peat seed starting pots.

Make sure you set the pots in a deep, waterproof tray or pan to collect surplus water. Buy the right growing medium. Young seedlings are very vulnerable to fungal and bacterial diseases. Protect them by buying a sterile seed starting mix. “It will have a finer texture than regular potting mix, so it’s easier for little roots to push through,” he said.

Don’t plant too deep. Follow the directions on the seed packet. In general, plant a seed into a moist potting mix 2 to 3 times as deep as the width of the seed. A tiny radish seed should be barely sprinkled with soil, but a big bean or other large seed may need to go a half inch deep. Warm, then cool.

Many seeds will only germinate in a warm environment, such as over the refrigerator or dryer. As soon as they sprout, move them promptly to a cooler place to keep growing. “Seedlings like it no warmer than 70 degrees,” Campbell said. An electric seed starting mat, like a very gentle heating pad, may be useful if you start seeds often.

Water carefully. Once seeds sprout, keep the potting mix moist but not soggy. “Soggy soil will invite rot,” Campbell said. Check the plants every day. If the surface of the potting mix feels dry to the touch, water gently. Time it right. The seed packet will tell you how many days the seeds of each plant variety will need to grow large enough for transplanting outdoors.

Use that information and the average date of the last frost — about May 15 in USDA Zone 5 — to calculate when you need to sow them. Stagger your crops. For a longer harvest, sow batches of each kind of seed a week apart so they will also mature a week apart. It will give you a cushion against the variability of spring planting weather.

Advertisement Sow the right number of seeds. “Be realistic about how many plants you actually need,” Campbell said. Read the seed packet to understand how far apart the plants will need to be planted in the garden and decide how many you have room for. “It’s a good idea to plant a few extra just in case,” Campbell said.

“You can give extra transplants away to friends or family.” For tree and plant advice, contact the Plant Clinic at The Morton Arboretum (630 719 2424, mortonarb.org/plant clinic , or plantclinic@mortonarb.org ). Beth Botts is a staff writer at the Arboretum..