Re: SPEC: I. virginica seed
In a message dated 8/7/00 8:10:04 PM Eastern Daylight Time,
<< I'm new to this, so please bear with me. Have collected some roadside
seed that I think is I. virginica, though might be versicolor. Does
it need to be stratified, or can it just be kept dry for planting out
in the fall? I'm in NE North Carolina, adjacent to the Outer Banks on
the mainland. Zone 8. >>
Jim, the basic question to bear in mind when considering what conditions a
seed will need met to germinate is "What does the seed naturally encounter in
its native environment?"
In the normal course of things both these wetland irises would mature their
seeds, which would drop as the pods ripened, and the seeds would fall to the
moist earth, or to marsh waters,or placces that seasonally flood, and then be
carried hither and yon. They would shake loose from the pod gradually and
some might even remain over the winter, falling when the snows or spring
rains broke the brittle remains of the pod apart.
Now, when it comes to perennial plants Nature generally does not want seeds
to germinate in the fall unless they are comparatively hardy. She may also
want there to be a lag time so that the seed can get dispersed. So some seeds
seeds are programmed to need a good cold spell before they will germinate.
Obviously seeds native to the tropics will not need a cold spell, although
some native to very cold areas do not either, Nature having chosen to program
them with other inhibitors, physical or chemical.
Some seeds, for example, do not need cold, but do need prolonged exposure to
moisture to remove chemical inhibitors. Still others need to loose seed coats
or fruit that surrounds a seed to remove germination inhibitors in the fruit
or either expose it to light, for exposure to light is a necessity for some
seeds. Some few, like lilies of the valley, must be totally dark
Sometimes the length of time a seed has been mature changes what is required
for germination. That is, it will germinate quickly when fresh, but if dried
and stored it will require a cold spell. Some seeds will respond to several
different or alternate conditions, or sequences of conditions, others are
very specific and demanding.
All species Iris seeds do not have the same germination requirements, but
many of the swamp irises do not require any cold, although some may benefit
from some chill. As we said, their seeds will drop into soggy places or
places which flood, and they may float away and be deposited apart from the
mother by tides and so forth. This is a dispersal mechanism. Thus swamp iris
seeds as a group tend to want a good soak, and then they want warmth and
Now, if you want your neighborhood seeds to germinate as they would in
nature, then you will wish to keep them dry until about December, then
surface sow them outside in little pots which you protect from rodents and
the like but not from rains and snows. They will emerge at the right time in
the spring just as they would in the wild. Keep an eye out for slugs.
If you want to get a head start next year, keep them dry, then in February
soak them about a week in several changes of tap water; longer is not better.
Then sow them thinly on the surface of moist medium or vermiculite and cover
with saran. Place in a bright warm area but not full sun and keep an eye on
them. They will probably emerge in 2-4 weeks. Uncover them gradually once
germination starts. Keep moist not wet. They will grow pretty rapidly and
about a month or six weeks later when they are about two inches tall you will
want to move them up into cellpacks or whatever. Keep potting them up to
ensure they have a good root run and by fall you should have something to
plant into the garden.
If you want to see if your seeds benefit much from a chill, soak them, sow
them, put the little pot into a plastic bag that is loosely closed, and stick
it in the humidor area of the refrigerator for a month before bringing into
If you have enough seeds, try it all three ways and see what sorts of results
you get with each. Be prepared for their to be a lot of non-viable seeds or
empty seed coats, for that is not unusual with this sort of iris.
Anner, in Virginia
Open the door to endless possibilities for your home!