by Ray Greenstreet
Starting plants from seed is a great way to garden mid-winter. You are able to get your hands dirty, smell soil, see green and enjoy the simple satisfaction of growing your own plants from seed to harvest.
Starting seeds indoors is not difficult, but seeds have basic needs for good germination and healthy growth. This column runs through those basics to get you started growing. If you’re a first-time seed-starter, begin by learning with just three or four seed varieties. It doesn’t look like much, but each seed packet is capable of producing dozens of little seedlings.
Before it’s time to move them outside, which is usually our last frost date (April 11th, 2016), read the seed packet to find out how many weeks each variety will need to grow indoors. This is usually labeled as “days to maturity” on the seed packet. Successful growing starts with the right growing medium. Garden dirt or regular potting soil is too heavy. Use fresh, sterile seed-starting mix, which is available at garden centers or wherever you purchase your seeds.
Thoroughly moisten the growing medium with warm water, and fill your containers within 1/4 to 1/2 inch from the top. As for growing containers, seeds aren’t picky. Anything that will hold the growing medium will work. But it’s crucial to clean them and sterilize them in a solution of one part bleach to nine parts water. Make sure they have good drainage holes so excess water can drain away. An alternative option is to use pots that break down in the soil. You can plant them right in the garden and avoid disturbing the young plant’s roots.
Scatter the seeds on the soil surface or place individually into each growing cell. Don’t sow seeds too thickly. Read the seed packet for specific planting instructions. Use a mister or just drips of water to gently moisten the growing medium. Label each flat, row, or container so you can identify them later. Save the seed packet for reference.
Some gardeners cover their flats or containers with clear plastic until the seeds germinate. This helps trap heat and moisture. Seed-starting kits are readily available and can be a big help. They usually include an attached set of good-sized containers, a tray to set them on and a clear lid to hold in humidity during the early stages.
At this stage seeds don’t need much light, but they do need gentle warmth to germinate. Set the containers on top of a refrigerator or dryer, or purchase special heating mats sold for this purpose.
Check the soil every day. It needs to be moist but not soggy – you don’t want the seeds to rot. Your seedlings will be much happier if you water them with room-temperature water rather than ice-cold tap water. If your water is chlorinated, fill some plastic jugs and leave to settle overnight so the chlorine dissipates. Don’t use water that has been through a water softener. The sodium may kill your seedlings.
Most young plants like a humidity level of 50 to 70 percent. If the air in your house is very dry, you can keep your seedlings happy by setting them in a waterproof tray filled with small stones and a small amount of water.
When the sprouts are about half an inch tall, it’s time to turn on the light and turn down the temps. Room temperature, between 60 and 70 degrees will be ideal. Seedlings need 14 to 16 hours of direct light to manufacture enough food for healthy stems and leaves. If your plants grow leggy, they’re not receiving enough light. If your seedlings are growing in a south-facing window, increase the light by covering a piece of cardboard with aluminum foil and placing it in back of the seedlings. The light will bounce off the foil and back onto the seedlings.
If you don’t have adequate natural light, you can purchase fluorescent “grow” lights at garden and home centers. If you are growing your seedlings on a windowsill, you may need to supplement with a few hours of artificial light, especially during the winter months.
Before you know it, you’ve got pots of baby plants. Now what?
Once your new plants develop a second set of leaves, they’ll need fertilization. Use a liquid fertilizer at half strength doses until they are three or four weeks old. After that, fertilize weekly according to the directions on the fertilizer package.
As the weather gets warmer, start “hardening off” your seedlings. At least one week before you plan to transplant your newly grown greens into the garden, take them outdoors for an hour or so each day, ideally on a protected porch. Gradually increase the amount of time outdoors. Be sure to protect them from too much wind and hot sun.
Gardeners are always eager, but if we’re have a cold spring, be patient. After weeks of nurturing your seedlings, you don’t want to lose them to a late frost! Happy and successful growing! And stay tuned for tips on growing your outdoor garden.
Ray Greenstreet is the owner of Greenstreet Gardens in two Alexandria locations and headquartered in Lothian, Maryland.