Plant
Care
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Giving
Seeds Their Wakeup
Call As
gardeners know all too well, as soon as the soil warms in spring,
there will be a plethora of new weeds to contend with. These are
the progeny of last year's flowers, and they have bided their time
until conditions were just right for germination. By delaying germination
until spring, they will maximize their growth before having to contend
with their first winter. Seeds use various chemical and mechanical
means of inhibiting germination until the time is ripe. But not
all seeds go through a dormant period. Most seeds sold commercially
through catalogs and nurseries have been hybridized for generations
and will usually come up as soon as planted. Where the gardener
is likely to encounter problems is with seeds of native and woody
plants. But for seeds with thick, hard walls, even commercial seeds
may need some help.
Faux
Winter
In most
cases, what is needed is a little faux winter. It isn't really necessary
for the seed to spend the cold months in the ground, as long as
it thinks it did. This deception can easily be performed by placing
the seeds in a small container with moist (not wet) sand, peat or
vermiculite, and leaving it in a refrigerator for four to six weeks.
This procedure is known as stratification, purportedly because of
the layering of the seeds within the medium.
Cutting
to the Quick
For seeds
with hard coats what's needed is a little nick in the pants. This
is known as scarification. While in natural conditions this coat
would eventually be broken down, the impatient gardener can speed
the process by using a knife or file to make a shallow cut. This
will allow moisture to enter and the seed to germinate. For instance,
the large, hard seeds of the moonflower vine, Ipomoea alba, rarely
germinate unless their coat has been notched. For other seeds, immersion
in warm water will often do the trick. Seeds like those of the native
columbine of the eastern U.S., Aquilegia canadensis, need to be
exposed to a certain amount of sunlight before they will germinate.
Finding
What Works
So how
do you know what procedure a particular seed needs? Well, the best
way is to find a book that covers the type of plants you are trying
to propagate. Or, you can be a true cyber-gardener, and post a message
to our Growing from Seed Forum. Much of the advice you find will
be based on the experience of trial and error. And often one authority
contradicts another. But gardening isn't meant to be a purely logical
pursuit. For most of us, the learning is the fun.
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