Most seeds are covered to the depth of their diameter; very fine seeds are merely firmed down into the soil. Seeds with hard coats may be gently nicked with a knife or soaked in water for a day or so. Some seeds, like primroses, need to be treated as if they had wintered outdoors before they will germinate. You can put them in moist sand in a small, tight container and alternate freezing in the ice compartment and thawing in the warmer part of the refrigerator for several days. Or you can plant these seeds in a small box or flat of their own and leave them outdoors, in a protected spot, where winter will supply its own natural conditions.
Cold frame planted and ready for top made from discarded storm windows
Some seeds germinate faster in the dark, some with light; some like cooler temperatures than others; some come up in seven days, some take months or even a year. Seed packets usually supply pertinent information.
Seeds will not germinate in dry soil, or if allowed to dry out even temporarily during the critical period. To avoid washing out fine seeds, water gently with a fine mist, or set the flat or other container in water up to the level of the soil inside. When the soil surface looks shiny and moist, remove the container and set it aside to drain.
When the first “true” leaves are of fair size, transplant the seedlings to peat pots, or flats, or rows in a prepared bed or cold frame. Shade against sun and wind until they resume growth.
Stem Cuttings
Many perennials can be propagated easily and in quantity by rooting softwood cuttings like those of trees and shrubs. Tip cuttings three or four inches long are usually best, with all the flower buds and the lower leaves removed. Some types, such as dianthus and lavender, root faster and more surely if the cutting is taken with a heel.
For spring-flowering varieties, take stem cuttings after flowering has finished and up until midsummer; for those that bloom later, take cuttings in May or June.
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