For variety, convenience grow your own

The next couple of weeks are perfect for starting seeds indoors, and there are several advantages to starting your own seeds, the biggest one probably being that you can grow the varieties you want instead of hunting high and low for that unusual type of petunia, tomato or delphinium.

You don’t have to take the chance of ordering live plants from a catalog and hope they arrive on your doorstep healthy and big enough that you can find them in the shipping box.

Lastly, in the long run, if you want to grow a lot of plants, it’s cheaper to invest in the lights, equipment and space than it is to buy the plants.

Do the math: A gallon-sized plant can set you back between $5 and $10. Buy four or five of them, and you’ve spent the equivalent of a set of fluorescent lights, starting trays, germinating mix and the seeds that could grow 10 times that number of plants.

Light is the trickiest element to get just right. Plants are very sensitive to the intensity and amount of sunlight.

When the light intensity drops and the days become shorter in the fall, the plants go dormant. As the light intensity increases and days lengthen in the spring, the plants switch on their growth mechanisms.

In the northern latitudes where we live, the days are still several weeks away from being long enough to stimulate growth. We have to provide that extra kick of light to switch on the seeds’ germinating mechanisms

There are all kinds of grow lights on the market, and each has its place, depending on what and how much you want to grow. For the home gardener who just wants to start a few flats of flowers and vegetables, ordinary shop-grade 4-foot fluorescent light fixtures are the cheapest and easiest light source.

Fluorescent light fixtures can be fitted with special tubes that emit the wide ranges of light wavelengths needed for good growth. They stay cool so they can be hung just a few inches above the plants without damaging them.

Lastly, they are inexpensive to buy and operate. Add an inexpensive timer set to provide about 16 hours of light a day, and the light system can basically run itself.

Most newly sprouted seedlings prefer night temperatures around 60 degrees and daytime temperatures around 70. In a household environment, this makes that spare bedroom or corner in the basement the perfect place to set up your growing racks.

If you have an automatic set-back thermostat, the job is practically done for you.

If you are using a sunny window, be aware that Mother Nature is right outside the window and the night and day temperatures can fluctuate by several 10s of degrees. Most tender seedlings can’t handle that kind of temperature shift.

Rectangular plastic nursery flats and pony packs like the ones you buy your spring plants in are ideal for starting seeds. They maximize the space under the lights, provide enough room for roots to grow and drain excess water away efficiently.

The flats and liners cost about $1 apiece and will last for several years with a little care.

New seedlings love humidity, so cover the flats with pre-fitted clear plastic covers to control the humidity. The covers can be left on until the plants start bumping up against the top. Covered flats are easier to keep watered, too.

Sow your seeds in a quality soilless germinating mix, high in finely milled sphagnum moss (not peat moss). This type of a mix absorbs and holds plenty of water but maintains the vital air spaces your seedlings need.

Be sure to moisten the mix very well a day or so ahead of planting. Each flat holds about 10 dry quarts of germinating mix.

Plant your seeds at the depth recommended on the packet.

Don’t start seeds too early. If you start seeds about the last two weeks of March, they will be just the right size to harden off and plant in the garden after our traditional last frost date of May 15.

Plants started too early can become stunted and actually will take longer to establish themselves in the garden.