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More on Seed Sowing
by Marg Fleming
by Marg Fleming



1979 - BSc. Botany University of Toronto, 1981 - MSc. Forestry University of Toronto, 1982-1986 - Horticulture Teaching Master - Niagara College , St. Catherines Ontario., 1986 - 2000 - Owner/Operator of Cedar Valley Botanical Gardens - Brighton Ontario, 2000- Present - Manager of Horticulture Toronto Zoo

Public Speaking Topics - Perennials, house plants, garden design


March 23, 2008

Seed packets and catalogues are storehouses of information for gardeners who enjoy growing their own flowers and vegetables. Everything from planting depth to temperature will be indicated on seed packets distributed by reputable seed companies. But even though general directions have been included, there still remains a measure of innate skill sensed by tiny seedlings that makes or breaks a decent supply of home grown plants.

Seeds sown early indoors will emerge at a variety of times based on the plant species. Marigolds pop up after only 3 days. Others have the irritating habit of requiring several weeks before the seed imbibes enough moisture to trigger sprouting. This phase takes a great deal of patience since all of the seed’s needs must still be met, regardless of its belittled presence beneath the soil. However, with the appropriate care new leaves will eventually push above the soil surface. Beneath the shoot is a new root system capable of providing the young plant’s needs. But the small plant is not yet “out of the woods” in view of its vulnerability to pathogenic organisms. Here are a few suggestions to consider when rearing young plantlets.

Young seedlings are targets for disease because of their soft tissues and underdeveloped defense systems. Too much water and not enough water will weaken them to the point where disease can overwhelm them. Monitor young seedlings at least twice a day if you are unsure of their moisture requirements. Water in the morning so young plants can work to assimilate the moisture during daylight hours, then enter the nighttime warm and reasonably dry. Fungus loves dark damp places, so insuring that the soil retains marginal moisture as evening falls can discourage disease.

As plantlets grow it is healthy for even them to dry out, but not wilt, for brief periods of time. Wet soil is cold because heat energy is occupied evaporating excess water from the soil. This re-directs warmth from the heat sensitive root system. Water seedlings early in the day, then resist watering again unless absolutely necessary. This will keep seedlings suitably moist without causing added chill from excessive evaporation.

Since plants evolved eons ago, mobility has not been a feature for which plants have been particularly noted. Therefore the gases required by plants for their variety of internal functions must be delivered to them via the wind or some other atmospheric disturbance. Similarly, gases released by plant tissues as waste biproducts are conveniently whisked away by natural breezes thereby refreshing the gaseous environment next to leaves and stems and delivering fresh gaseous material for them to metabolize. Invest in a small fan to stir the air around young seedlings. Indoors, pockets of stale humid air can stagnate around the seeding flats encouraging unseemly fungal characters. Direct the flow of the breeze up over the seedlings to create air circulation that will continuously remove waste gases and deliver fresh, dry air.

Soon seedlings will outgrow their nursery flats and demand more space for their roots and shoots. Before root systems become too complicated and difficult to extricate, the healthiest seedlings should be offered their own digs. Ask a local grower about a suitable soilless transplant mix and appropriate container upgrade. Seedlings can then be gently lifted from the flat where they were sown and transferred to a new container. With the use of a dibble – a tapered tool that facilitates the lifting and removal of young plants – individual seedlings can be selected for transplanting. Young stems should not be grasped when transferring. As careful as our fingers can be, any pressure is liable to crush tender stems and kill the little plant. Also, natural oils from our fingers can inhibit the normal function of stem cells and make the plant vulnerable to disease. Instead, gently pry a candidate seedling loose from its medium with the dibble, grasp a leaf or seed leaf, and lift to its new container. The leaf may perish from this contact, but other foliage will develop to take its place. On the other hand, once a main stem has succumbed to rough play the plant will not recover.

Now that the seedlings have moved to more spacious quarters, they will require comparatively more water, but only after they grow accustomed to the new container. Water the transplants after transferring, then keep the soil evenly moist until additional growth demands extra moisture.

As seedlings mature they develop their own natural defenses against skulking fungal diseases. Our responsibility becomes easier, but there is no time for complacency.

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