Proper soil is key for starting your seeds

If you're going to start your own seeds for the upcoming gardening season, this is the time of year to start planning. Not only is this a satisfying thing to do, it could save you quite a lot of money.

To begin to grow, seeds need moisture, warmth and aerated — not compacted — soil. A soil mix usually is better than garden soil for seed sprouting, as well as for transplanting seedlings when they outgrow the containers where they were started, because it is free from pests, diseases and weed seed. It also drains readily, holds some moisture and allows air to enter the mix. The texture is fine enough so there is good contact between the seeds and the seed-starting mix, which aids germination.

Several commercial mixes are on the market. They usually contain peat or coir for moisture-holding, sand or other "grit" for good drainage, and perlite or vermiculite to help with aeration. I prefer a mix using coir, which is a fiber from coconut husks, because it is sustainable, or renewable. Peat takes many years to form and must be mined; one of these days, we'll run out of it. You could make your own seed-starting mix using the ingredients listed.

These mixes, you will note, do not contain fertilizers, as everything a seed needs to begin to grow is contained within that seed. As the seedlings grow, they will need to be transplanted to containers that offer more food for the plants. The appearance of the seedlings' true leaves — the ones following the "seed leaves" — signals the time when transplanting can take place.

Transplanting mixes usually will contain peat or coir for holding moisture, pumice or perlite for aeration, and perhaps some ground bark, aged sawdust or sterilized garden soil. There might also be bone meal, kelp or other seaweed, alfalfa meal, blood meal and maybe some mycorrhizae or other soil microbes, all of which help feed the young transplants. These slow-release fertilizers are preferred to chemical ones because they won't burn the roots of the baby plants. Like seed-starting mixes, these transplanting mixtures are designed to prevent the growth of molds, which can kill the young seedlings.

If you want to make your own transplanting mix that includes garden soil or compost that you made, remember to sterilize the soil first. This can be done by putting fine, sieved soil into a baking pan, no more than 3 inches deep, and baking it for 30 minutes at 400 degrees. Warning: This process smells awful! Or, put the sieved garden soil in a roasting bag and microwave it on high for 10 minutes. Close the top of the bag to prevent the soil from getting into your microwave, but do pierce the bag so it won't explode.

There also are specialized mixes on the market for orchids, cacti, African violets and so on, which contain the special kind of texture and nutrients preferred by those plants. It's a good idea, I think, to use these special mixes, to get the best results from your gardening efforts.