Starting From Seed

All seeds may be sown outside in late spring, or started
earlier indoors.  Hardy trees, shrubs, perennials and
bulbs may also be sown in fall; cold will assist their
germination.  Houseplants sewn any time of year, though
ideally spring or early summer for most rapid growth.

Many seeds have specific germination requirements: 
special tricks are described below, and the needs of many
species are described in the alphabetic listing.  Make
sure to have ample seed if using trial and error.

In general, perennials, trees and shrubs from colder
climates germinate at cooler temps, perennials, tropical
plants, and many garden vegetables prefer temperatures
comfortable to most humans.  Requirements of individual
species vary considerably:  do not commit all your seed to
any trial of germination.

Plants can often be germinated at less-than-optimal
temperatures.  However, expect slower germination, a lower
percentage of germination, or both.

Dustlike seeds are left uncovered.  Mix well with larger
quantity of sand if you wish to distribute such seed
evenly.  Fine seeds are covered with fine layer soil. 
Otherwise, bury once to twice the depth of the diameter of
the seed.

Most seeds DO NOT require dark to germinate:  most will
germinate under any circumstances.  Good indirect light is
probably best under most circumstances.  If germinated in
the dark, uncover with the first sign of germination, and
expose to air.

Plant in moist, never wet, soil, and where possible, water
from below, setting pots in a tray of water for 20
minutes.  Plastic bags tented over the pots, or specially-
designed propagaters, prevent moisture loss by
evaporation.  Wicking systems may work well.

Humidity is essential for germination, about 50% works
well.  Too much moisture is a problem:  many seedlings do
not mind dryness for a day or two at a time, but damping
off is very serious fungal infection.  Uncover immediately
with germination.

Finally, warmth and light are necessary for germination. 
Place over fridge or a radiator, or use a heating pad or
special soil heating cables.  Southfacing windows or
greenhouses are ideal, though proper artificial lighting
is more than sufficient.


Dormancy

Many seeds go dormant if not sown immediately upon
ripening.  If unsure of how to break dormancy, try several
methods simultaneously for each seed, using small amounts
only.  Often shiny hard coats need chipping or soaking,
soft seed coats only stratification.

Stratification

Stratification or prechilling may be required to break
dormancy for hard-to-germinate plants, especially trees
and shrubs.  Those plants that expect two winters before
germinating, require a double treatment.  Sow such seeds
in the garden, in the fall, ideally in a cold frame for
protection and easier observation.

Alternatively, in early winter, mix seeds with builder's
sand or some other sterile, well-draining medium and place
in clay flowerpot, or perforated plastic pots, and set
outside in a protected location.  When the snow clears,
empty the pot, and sow swollen seeds either inside or out.

A sterile, moist growing medium may be used for the above
technique.  Check daily for germination in spring and move
to warmer area when this happens.  Transplant when the
seedling has its first or second set of true leaves.

The refrigerator will substitute nicely for cold winters. 
Mix seed with 3 times that amount of damp peat moss, damp
sand or other sterile medium and seal into a plastic bag,
leaving plenty of air available.  Leave at 60-65F (15-18C)
for several days then refrigerate.  Check frequently for
germination.  Keep damp.

When any seeds germinate, pot them all.  Note that
germination can take years, even after stratification. 
Don't give up hope and don't throw away good seed.

Chipping

Some hard seed coats are largely impermeable to water. 
These benefit from having the seed coats lightly nicked,
using a needle or fine knife.  Gently shake very fine
seeds in a small empty bottle with a piece of sandpaper. 

Soaking and Pricking

Seeds can be soaked to soften the hard outer coats; this
may also leach out chemicals that inhibit germination. 
Use lukewarm water, for several hours to overnight, where
required.  DO NOT allow seed to dry out before planting.

Some species will not swell when soaked and are simply
planted, in other cases, only those which swell may be
planted.  Prick the remainder gently with a pin and
resoak, then plant when swollen.