From The Garden of Ed. Submitted for publication in The Towne Crier on March 8, 2006

Gardeners, Start Your Seeds!

In my last column, I suggested the time was drawing near to consider what you want to plant in your vegetable/fruit garden. The choices are heirlooms, hybrids or standards. It's just twelve days to the vernal equinox-- days and nights of equal length. It's time to start seeds, especially those that can be planted out early, because they enjoy the cool temperatures of April.

This month start seeds of the following cool weather crops, which can all be planted out a month before the last frost. These include beet, broccoli, Brussels sprouts, early cabbage, carrot, cauliflower, leek, head lettuce and onion. Many others can be seeded directly into the garden as soon as the soil can be worked. For now, however, we are concentrating on starting seeds indoors.

But lets examine a few basics first. Seeds prefer a loose light soil in which to germinate. Lightly cover seeds with soil that is three to four times their thickness, no more than that. Larger seeds may be soaked overnight and then planted individually. Flat seeds are best planted edgewise. In general, small seed should be just barely covered, as mentioned above. Fine seed should only be sprinkled on the surface and then watered in with a fine spray mist. Soil must be kept moist but not soggy or saturated. Bottom heat hastens the germination process, but care must be taken to make sure the starting medium doesn't become too dry, especially for small seeds.

Soils to start seeds can be of a variety of sources. One approach to soil mixes suggests sifting through 1/4-inch wire mesh in the following volumes: two parts of loam, one part of peat moss, one part coarse sand. Mix thoroughly. There's one mix.

Many gardeners add well-rotted manure, bone meal, blood meal, lime, vermiculite, fish emulsion and compost. Some achieve a light, loose mix and then sterilize it. A word of caution about sterilization: Do not exceed 180 degrees F for more than ten minutes. Otherwise nitrifying bacteria may be killed, but not ammonifying bacteria, which might reach toxic levels. This happens not infrequently when soils are heated to 212 F. I have seen some directions calling for 250 F for two hours. It'll be sterile, all right, but dead, too.

Whatever seed-starting medium you choose to use, you want to make sure it is free of any disease, weed or insect pests. Same for the flats, pots or planting containers. Wash them thoroughly in a 10% bleach and water solution if they were used before. If new, this shouldn't be necessary.

Causes of a plant seed's failure to germinate are: soil too heavy, kept too wet or cold, allowed to dry out, planted too deeply or covered with too much planting medium. Seedling loss can result from damping off, a result of over-watering or insufficient air circulation in the presence of a fungus disease that causes stems or roots to rot. Introducing seedlings to full sun or outdoor conditions too early is another cause. Sterile soil and containers can keep the fungus problem at bay.

A lot less trouble and a time tested alternative is to use one of several manufactured soilless mixes that are sterilized and designed for seed germination. While more expensive, they are nearly foolproof. Ask at your local garden center.

Optimum germination temperatures are between 70 and 86 degrees F for most seeds. Corn, cucumbers, melon and squash like it even warmer, closer to 95 F, but it's too early to start these now.

I haven't mentioned seed viability yet, so it's time. The word "viable" means "alive" or "able to live". A seed is a tiny plant embryo surrounded by a protective coat. Inside is a bundle of complex information - truly all that's needed to produce a whole, healthy, complete plant. It is asleep, so to speak, or dormant. Among the internal ingredients is an important sensor known as phytochrome. It is sensitive to a number of environmental factors that spell out the sequence of breaking dormancy. These factors include light, temperature, moisture and oxygen. When all are at or near optimum levels, the phytochrome changes, the seed's sleep is ended and it germinates.

The seeds you have to start, if purchased this year, are likely guaranteed to be fresh and viable. If saved form previous seasons, you ought to perform a simple test of viability first, so as not to waste time and materials. On a few pre-dampened sheets of paper toweling, place seeds for germination testing with a little space between each. If testing several kinds, repeat for each. Use at least 10 seeds of each variety - more is better, if you have a lot.

Roll up the towels to keep seeds separate and in place, and put into a plastic bag and affix a label to the outside. Place in a warm (70-80F) environment, and check after three days and every day after for about a week. After a week, check the germination rate by dividing the total number of seeds tested into the number germinated. It is usually not worth trying to plant those that germinated, as injury is likely to occur. If the percentage is high, say above 75, use the seeds or plant extras to be sure you have all you want. If the rate is low, purchase new seeds.

As soon as seeds sprout, sufficient levels of light intensity and duration are essential. These are the key ingredients, and you must make provisions for them or wait to start seeds outdoors when soil and air are warm enough and light levels are adequate (this is usually at the same time, on or about early June). What you are trying to do is get a jump on the planting season, so you can be a few weeks ahead and see results earlier and have a longer growing season. A simple light table with a fluorescent fixture or two suspended above it works well. Even a few 40-watt incandescent bulbs will work fine. Improvise.

A friend uses a two-bulb fluorescent fixture with aluminum foil on the back wall and clear plastic curtain over the front. He has created a miniature greenhouse with rear wall reflecting light back onto the seed trays. If using fluorescent lights, the bottom of the bulbs can be kept as close as three inches above the soil or seedling tops. Incandescent bulbs are hotter burning, so more distance is required.

Set all your pots, egg cartons, recycled gray paper fiber pots, peat pots - whatever you've chosen to use for sprouting your seeds - into trays that are watertight. Any moisture collected there will increase the humidity and serve as a vehicle for watering your containers from the bottom so as not to disrupt the delicate seedlings as they germinate.

Once seedlings have developed their first true leaves, it's time to move them to larger pots or flats. Space the new transplants two inches from one another. Air flow between them is important. As they become stronger, let's say after three weeks, they will have used up most of the built-in food supply and will benefit fro a light supplemental feeding. Use a liquid fertilizer mixed according to label directions. A little weaker is safer than overdoing it.

As plants approach the time for planting into the garden, it is important to acclimate them so they are not shocked when that day comes. "Hardening plants off" is a term used to express their periodic exposure to outdoor weather conditions. Letting them receive outdoor temperatures and bright light while protected from direct sun and strong wind prepares them and makes them robust. Over the space of a week or maybe even two, you can gradually increase their exposure to sunlight, making sure that they are brought in at night if there is a threat of very cold temperatures. After this period, your plants will be hardened off enough to be planted into the garden.

Transplanting is best done on a cool, cloudy day, late in the afternoon after any midday heat. This will reduce any initial transplant shock. Healthy transplants should be short, sturdy and dark green. Plant them up to their first true leaves. Water lightly and wake up in the morning with enthusiasm. There's a lot more to do during the rest of the growing season. Good luck and good growing. Don't forget to mulch.


From The Garden of Ed. Submitted for publication in The Towne Crier on March 8, 2006

© 2006 Ed Mues. All Rights Reserved.