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Propagation Lecture Series Part 4: Seed Germination Part 2

      PROPAGATION LECTURE SERIES PART 4:  SEED GERMINATION PART 2
                            (By Amber Hearn)

SEED SOURCES:  There are several hundred commercial sources for the hobby
gardener to obtain seeds of garden plants, vegetables, shrubs and trees.
Since I'm limited in time, and space, I would like to suggest the following
starting points:            

	Cindy Johnson's catalog of catalogs is available on-line at the following
address. http://www.cog.brown.edu/gardening/  She lists nearly 2000 mail
order catalogs, both for plants and seeds, along with relevant information
about the catalog.

	"Gardening By Mail (A source book)" By Barbara J. Barton, published by
Houghton Mifflin Books.  Ms. Barton's book is a huge source of mail order
businesses having to do with anything in the horticultural marketplace.  You
can find references for seeds, plants, bulbs, about any garden product,
magazines, and addresses for garden clubs, societies and organizations.  The
information is indexed by product type and geographical location.  Each
entry gives a short description of the products available by the company,
the catalog price, and more.  When I bought my copy, it retailed for $18.95,
but there has been a new edition published since then.  There are rumors
that it is being published, at least in part, on-line, but I haven't been
able to find it. 

Don't overlook the garden clubs and associations as a source for seeds.
Often, they may be the only place you can find seeds of rare plants.  The
North American Rock Garden Society, for example, publishes an annual seed
exchange list to it's members, that contains nearly 2000 species of rare and
unusual plants.  Many of these seeds are collected by their members, or are
made available by seed hunting expeditions to remote geographical locations. 
Membership information, and a copy of last years seedlist are available on
line at the following site.  http://www.mobot.org/NARGS/index.html   You can
not order seed unless you are a member of the society, but often the seeds
are made available at such a discount to members that it pays for the
membership fee.  There are several such organizations, all with different
specialties, that do the same thing.  Most are listed in Barb's book, and a
lot of them have a web page.  Here are a couple that I've run across surfing:

The American Fern Society Homepage: http://www.visuallink.net/fern/index.html
	  -Has an annual spore exchange for members.

The American Horticultural Society:  http://eMall.com/ahs/ahs.html
	  -Offers a free seed exchange for members.

The Herb Society of America:  http://www.herbsociety.com/     
   -Seed Exchange. I couldn't tell whether or not you needed to be a member.

# My comments (Duncan McAlpine)                                              #
# Alpine or related plant Societies: http://www.eskimo.com/~mcalpin/soc.html #
	
COLLECTING SEED:  In your search for seed, don't overlook collecting your own
garden, and those of your friends.  Many hardy garden plants, trees, shrubs,
and even some vegetables set good seed crops that are available for the
taking.  Just don't collect seed of hybrids, unless you are just
experimenting, as you never know what you're going to get. As we discussed
previously,  true species are the best candidates for seed as they will
produce with little variation.

It is a common misconception that the only time to collect seed is in the
late summer and fall of the year.  This is entirely untrue for many species.
Each plant is designed to set seed within a fairly short period of time
after it blooms and is pollinated.  With plants that bloom in spring, you
will usually find seed set by early summer.  Keep an eye on the target
plants.  After blooming, if pollination has been successful, they will begin
to form fruit or seed pods.  It is a matter of timing on your part to
collect the seed before it has been released from the parent.  When
collecting seed, place each type, variety or species into a separate
container such as a
paper lunch bag, and label it with the name, date, and place of collection.
Fruit seed will have to be cleaned when you get it home, and most seed that
comes from a capsule or pod will need several days of drying before packaging.

FRUIT SEED: ( defined as any seed encased in a pulpy mass as opposed to a
dry shell, including nuts that are surrounded by a fleshy coating).  In the
case of fruit seed, the seeds are mature when the fruit changes color.
(Strawberries turn red, Blackberry Lilies turn purplish-black,
Jack-in-the-Pulpits turn red, etc.)  The thing to remember, that except for
green apples, gooseberries and a few others, most fruits do not remain green
when mature.   Collect the seed, when the fruit is ripe, then remove the
seeds from the fruit.  This is necessary to remove chemical germination
inhibitors that may be present in the flesh of the fruit.  It was once
believed, that fruit seed didn't germinate easily because the seed coats
were impervious to water, but this theory has been disproved by Norm Deno,
and others working in the field.  Deno's research has shown that in
actuality, there is usually a water channel in the seed coat that allows the
inhibitors in the flesh to continually reach the seed, preventing it from
germinating.  If a fruit sits around long enough in storage, all the
chemical is used up, and the seed will germinate inside.  If the flesh is
removed, and the seed itself contains no further blocking mechanism, the
fruit will germinate within days.  Unfortunately for the grower, there are
often additional inhibitors contained within the seed itself that continue
to prohibit germination until they are used up or destroyed. These are most
often destroyed by cold storage, which we'll discuss a little later.

With large one-seeded fruits, removing the seeds is fairly easy.  With
fruits such as strawberries, kiwi, or tomatoes, the seeds are well attached
to the fruit, are also tiny, and are difficult to remove.  In these cases, I
use the following method to help separate the seed.  First mash the fruit.
Large seeds can be removed and wiped off on a paper towel. Small seeded
fruits are pushed  through a strainer or sieve.  Next place the whole mess
into a  container, add water to cover, and stir.  The pulp and the seed will
begin to separate.  The seeds may or may not float.  Another common myth is
that only good seeds will sink, but this is not necessarily true.  It is
however, easier when they sink because you can dump off the water and pulp,
and end up with fairly clean seeds at the bottom.  If they float, wait until
the water settles and, using a spoon or other implement, dip the seeds off of 
the water surface.  You may have to repeat this process several times to
effectively remove most of the pulp.  

In the case of tomatoes, kiwi, and other seeds with a gelatinous coating,
the following is recommended.  Place the seeds and as little pulp as
possible in a container. Add just enough water to cover.  Let the seeds set
for a few of days, stirring daily.  The pulp will begin to ferment and rot
away, allowing the seeds to sink.  When most of the seeds are loose, pour
off the top and rinse the seeds in fresh water.  

Some growers also wash the seed in a grease removing dish detergent to
further remove any oils that may contain germination inhibitors.  I hate to
name product names, but Joy is an excellent choice for this.  I've never
heard it expressed elsewhere, but Lemon Joy contains some citric acid, which
may help break down the stubborn oils attached to the seed coat.  In fact,
with some varieties, a daily soaking  in fresh water for a week or more, may
be necessary to remove germination inhibitors.  I like to add a few drops of
fresh lemon juice to the water to help clean the seeds, after an initial
cleaning with detergent.  (Some experts use solutions of acid to treat seed
before sowing for the same purpose, but most acid is a dangerous thing to
keep around the house, if you can even obtain a supply)  Do not leave the
seeds soaking in water, but rinse them thoroughly, and store them in a damp
paper towel in a plastic baggy between rinsings.  Rinse until the seeds feel
clean and smooth, and don't leave your hands feeling oily. Before sowing, it
is a good idea to cut open a seed or two to make sure there is living
material inside. Many plants produce a lot of seeds with empty seed coats. 
In general, if the seed material is plump, firm and white or cream in color,
the seeds are probably viable.

With most fruit seeds, allowing them to dry between the rinsing and sowing
process is not a good idea, as this seems to either kill them, or send them
into a deep dormancy.  (There are exceptions, primarily fruit from annual
plants, such as tomatoes, squash and watermelon.)  Fruit from trees, vines,
shrubs and perennials often needs a cold conditioning period after the
rinsing process.  I use Norm Deno's paper towel method for this.  Simply
take a heavy duty white paper towel, folded in half three times, labeled
with the variety and date, and dampened.  Open the towels up two folds, then
place the seeds inside.  Fold the towel back up, place in a loose
polyethylene baggy, and place in the refrigerator.  Open them up every
couple of weeks to allow some extra air to circulate around the seeds, but
otherwise leave them alone for a period of  3 months.  When the three months
are up, move the bags to room temperature, and check them about once a week.
If germination doesn't begin within a two to three month period, it is
likely that a second cold period is necessary.  Repeat the process until
germination begins.  (See Norm Deno's book, described in lecture #3 for
complete details about this, and a complete explanation of how fruit seed
germinates).

There are other methods of dealing with fruit seed.  Nurseries that produce
in quantity, simply macerate the fruit, pack it in damp sand, pulp and all,
cover with an inch of sand, water well and place in the shade in the coldest
spot they can find, and let mother nature go to work. When germination
begins the seeds are then sown into seed beds or pots.  This process is
fine, but it is neither as fast, or as effective for the home gardener.  I
prefer the
paper towel method, because I can get two cold and two warm periods in the
space of a year, and I don't have to wait for the fruit to rot away.  A
combination of the two methods may work well too.  The important thing to
remember, is that not all seeds will germinate in one year, some take two or
more, so don't throw seeds away until you are certain they are not viable.
I can't count the times I've given up too early and tossed the seeds into the
compost pile only to have seedlings show up there the following spring.

Well, I've run out of time again.  Next lecture we'll take up the thread
with a discussion of how to store and germinate seeds from pods and seed
capsules. 

Addendum: Gardening by Mail is now available on-line in part at
http://www.vg.com/gbm

	
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Amber & Wayman Hearn                    jadare@accessus.net
Whippoorwill Creek Nursery              USDA Z-5
943 Foxville Road                       mintemp = -15F/maxtemp = 102F
Kell, IL 62853
618-822-6000
Perennial Editor, http://www.suite101.com/
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-- 
Sincerely,  

------------------------------------ FROM: -----------------------------------
Duncan McAlpine
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