Hill Gardens of Maine - Getting It All Together For Spring Seeds

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Getting It All Together for Spring Seeds
by Fred Davis, MG, Hill Gardens of Maine (To view other Our Garden Gate articles, click: Archives)

Welcome through Fred's Garden Gate! For those of us who get a 'kick' out of doing a few things on their own (and enjoying some welcomed relief for their strained checking accounts in the bargain) the time for getting our acts together for spring seed-sowing is at hand.

First—and most important—is sanitation. Tiny, new seedlings can be destroyed by disease organisms that have taken up residence on unwashed containers left over from last year. Newly purchased pots, trays and inserts are usually sterile and don't need to be cleaned before use. If you plan on using last year's containers, however, they must be thoroughly cleaned to remove all traces of soil, dried-on plant residues and fertilizer salt accumulations. Washing and sterilizing pots and trays is a boring job but, if your seedlings are to survive the dangers they'll face in the next few weeks, it's a job that must be done.

The process is quite simple. I immerse our seed trays, pots and flats in a large, deep tray of hot water to which I've added some regular dishwashing detergent (about the same mix as we use for washing dishes). A little sloshing around and a couple of strokes with a scrub brush over the space of three or four minutes works well for me. Rinse very well to remove soap residue and allow them to dry on a clean surface.

Treat the tools you'll use when transplanting seedlings or handling soil in the same manner. It's also a good idea to clean the box, pail or cart in which you'll be mixing your soil. Imagine dumping out a bag of sterile seed-starting medium into a dirty (and therefore contaminated) flat or pail! Say "Good-bye, little seedlings!"

I use a soilless mix called ProMix BX as a base for most of my routine seed-starting projects. Moistened before use and passed through a 1/4-inch screen, ProMix is neat, about the correct pH - and convenient. It actually contains a very small amount of fertilizer to give plants a head start in life but in my experience, not enough to adversely affect germination. If the seed-germinating instructions call for exceptional drainage or aeration, I add about 1/4-volume of additional perlite or vermiculite.

If your bag of ProMix (or any other brand) has been sitting around for a while open to the air and dust, it would be a good idea to "pasteurize" it before use. First, moisten to the dampness of a wrung-out kitchen sponge. Then place in a metal pan or tray and heat in your oven to 160 (F) at the center and maintain that temperature for about 30 minutes. Be sure to allow it to cool down before sowing your seeds.

Some very fine seeds (and a few larger ones, too—read the instructions) must be sown directly on the surface and not covered. Most, however, require a thin covering. My favorite covering material is vermiculite that has been passed through a (clean) window screen. Vermiculite has the added benefit of being able to discourage damp-off—in most cases it prevents it altogether—yet it retains just enough moisture to promote germination.

Different brands of peat pots have long been an aid to the home gardener. Even some commercial growers use them, especially for some types of vegetable seedlings. They are light, easily stored and can be planted directly into the garden when plant size or spring weather permits, with little or no disturbance of tender roots.

Most homegrown seedlings will do just fine in the 2 1/4-inch size unless seeds are started too early. Once again, read and follow the directions on the seed packet or germination guide. In many cases, larger seeds can be sown directly into these peat pots, thereby avoiding transplant shock altogether.

Another convenience for home seed-starters is the little, compressed peat pellet that looks like a fat, brown coin and is usually covered with a type of fine netting. When placed in water, it expands rapidly to about 1-1/2 inches tall and is immediately ready for use. Consider peat pellets sterile unless they've been kicking around the shed or basement since last year. Most have a small depression in the center top, and that's where you press in a few seeds. Peat pellets are planted directly into the garden when plant size or weather conditions allow.

A heating mat can be a valuable accessory, but not a necessity. Since seedling trays need to be near the bright light of a large, sunny window, cool drafts can retard germination. Some farm 'n garden stores market a heating cable just the right size for one flat. I've found that embedding the wire in a flat of moist sand, then placing seedling trays, pots or peat pellets in another laid directly on top of the now-warmed sand works fine. It's thermostatic and maintains just the right temperature.

Finally, run down a sheet of either clear or frosted glass—or Plexiglas—just slightly larger than your seed-starting container. This clear covering allows light through but maintains constant soil moisture critical to germination. Be sure to remove this covering immediately after seeds have germinated.

More information about damp-off | Links to other sites | How long will seeds last in storage?

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