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PROPAGATION LECTURE SERIES PART 5: SEED GERMINATION PART 3

     PROPAGATION LECTURE SERIES PART 5:  SEED GERMINATION PART 3
                             (By Amber Hearn)

FRUIT SEED CONTINUED:  Before we begin talking about seeds produced in pods
or capsules, I wanted to clarify a couple of points from my last lecture. As
you may remember, I mentioned that some professional propagators treat
certain species of plant seeds with an acid solution to help remove the
stubborn oils that inhibit germination.  This may give you the mistaken
impression that this is the main reason that acid is used. Actually, the
concept of using acid, usually sulfuric, to treat seeds with, evolved from
trying to duplicate the effect of stomach acids on seeds.  As we discussed
before, many of the plants that produce fruit, have evolved along with
animals that subsist on the fruit.  As the fruit passes through the
digestive tract of the fruit eater, the acids present not only clean the
seed coat of any chemical germination inhibitors, but also assist in
softening, or abrading it, aiding in the speedy germination of the seed.  
While present research findings disagree with the notion that most fruit 
seeds need this for water to reach the interior of the seed, there are those 
that still use/acid solutions for treating all fruit seeds.  There may be some 
seeds that do need this to be cultivated by artificial means. Remember, 
I'm a perennial nursery owner, and have only limited first hand knowledge of 
starting tree seeds, where most of this behavior is reported to be found.  
I'm only reporting what I've read.

In summary, the following is recommended for collected fruit seeds: 
    1.  Remove the seeds from the fruit pulp as soon as possible after
        collection, using one of the methods we discussed, or one of your 
        own making.                                                              
 
    2.  Clean the seeds thoroughly in clear water to remove the remaining pulp
        that clings to the seeds.  It is OK to use a little elbow grease, 
        or even a scouring pad on larger seeds.
	
    3.  Give any seeds that have the slightest oily feel left to them a
        gentle scrubbing with a grease removing detergent.
        a)  It is a good idea to continue rinsing the seed daily in fresh water
            for at least one week. (I add a little lemon juice to the water). 
            Some seeds benefit from a longer rinsing cycle. The exception to 
            this rule is the seeds encased in a gelatin like substance or the 
            seeds of annual vegetables. If you continue to rinse seeds of this 
            type, germination may begin prematurely.
        b)  In general, at this point, if the seed is from an annual or tropical
            plant, you may either sow the seeds at room temperature immediately,
            or spread them out, allow them to dry, and store them until you are 
            ready to sow them.

     4.  Again, as a general rule of thumb, place the seeds of temperate zone
         plants into cold storage for, at least, 3 months (90 days), and then 
         move them to room temp. (about 70F).  If germination does not occur 
         within that period, repeat the cold and warm cycles until  it does.
	
For purchased fruit seeds, or seeds that have been dry stored, assuming that
the pulp has already been removed,  (this isn't always the case, I've
received seeds that has been stored in dried fruit) begin with step 3 above
and treat like fresh seed.  Seed that has been dry stored may not be viable,
or may take a lot longer to germinate than fresh seed.  This is not a hard
and fast rule, but before you waste your time, it might be a good idea to
open a couple and check them for life signs.  

Keep in mind that these are only general guidelines. They won't work for
everything.  If they fail, try something else. We'll discuss some other
germination tricks in a bit.  I use these methods because I'm an impatient
propagator. I want to see quick results.  Remember that each species has
evolved it's own methods of survival and germination of it's seed.  You can
always throw the seeds in a pot, set it outdoors, and hope for the best.

SEEDS FROM PODS/CAPSULES:  (This very general category, includes any of the
many seeds that are not encased in a fleshy fruit, but in a thin walled,
usually dry and papery capsule or pod.)  Unfortunately, the rules are even
less specific with these type of seeds.  I hope I don't totally confuse you,
but I'll try and give some basic guidelines for collecting, storing and
germinating these seeds.  First of all, collect them when the pods begin to
open.  This indicates that they are ripe. Second, clean as much excess
material (chaff) from the seeds as possible before sowing or storing.
Disposition and storage are another matter.

As you may have surmised from our talk on fruit seed, how a seed is dealt
with after collection is quite important. Some seeds in this category do not
tolerate being dry stored any more than many of the fruit seeds, and if they
are, they may die, or go into deep dormancy. And this time I do mean the
word dormancy.  Conversely, there are other seeds that will not germinate
well unless they are dry stored for a period of time before sowing.  Yet
others have impervious seed coats that must be corrupted before water can
enter and germination begin. There are some that germinate immediately if
sown in warmth.  There are some that germinate in cold temperatures only.
There are some that germinate in warmth, but  need a cold period first. And
there are some that need a warm period followed by a cold period.  There are
even quite a few that need warm day temperatures and cool nights to
condition them. And if that isn't enough, some require light, and a few need
darkness. And you thought fruit seed was complicated *Grin*.

So if you don't know which is which, how do you figure it out?  I will not
pretend to have all the answers.  I can, in fact, guarantee you I do not,
and not even an expert like Norman Deno does, although his books are of
tremendous benefit here.  But there is always an answer, and the answer can
be usually be determined by observing the plants natural habits, or using
the information that you have or can find about a purchased or traded seed
to make an educated guess.  If you have the plant, note when it sets seed.
This will give you some clues. 

I divide the seeds into three basic categories, those to sow immediately,
those that need to be dried out before sowing, and those that have
impervious seed coats. Here are some basic guidelines to get you started. 

SEEDS THAT SHOULD BE SOWN IMMEDIATELY:  Many plants can be sown
immediately, but seeds of these plants will be difficult and on rare
occasions impossible to germinate if they are not.

Spring ephemera's is the first type falling into this category.  These are
normally woodland or understory perennials, often bulbs, that put up foliage
very early in the spring, and bloom before the average air temperature hits
70F.  Many of the seeds of these plants need to be sown fresh, or
alternatively stored in a moist cool environment until time to sow them. If
seed of these plants is allowed to dry out before sowing, germination may
take 3 or 4 times as long, and some few may never germinate. After cleaning
these seeds, I wrap them in a moist paper towel, place them in a baggy, and
store them at room temperature until early fall when they are sown into
seedling pans and placed out of doors in a cold frame.  Many of them will
germinate with the onset of cool nights and warm days. Others germinate the
following spring. Alternatively, you could place the seeds in your
refrigerator each evening, and germinate them in the towels.  Some examples
of these plants are Trillium species, Dicentra (Bleeding Hearts and
Dutchman's Breeches), Delphinium tricorne (Wild Larkspur), Corydalis species
(Fumitory),  Sanguinaria canadensis (Bloodroot), and Eranthis (Winter Aconite). 

The other seeds that fall  into this category are those woodland species
that set seed in early to late fall.  Often these seeds fall to the ground
and germinate immediately. The tiny seedlings then overwinter in the ground,
and begin growing with the onset of warm weather. The classic examples of
these plants are Aconitum (Wolf's Bane), Cyclamen, and late blooming
Helleborus sp. (Christmas Rose) and Arisaema species (these can also be
considered a fruit). I place these seeds immediately into seedling pans, and
follow the cool night, warm day pattern that is used for the spring species. 
You may of course also sow them into towels.
  
Sometimes, the only way to obtain these plants is to buy seed.  If you
obtain seed of one of these plants that has been dry stored, sow them into
towels in the refrigerator, and alternate cold and warm cycles until
germination begins. I find it helpful to start with a cold cycle, then after
2-3 months remove the seeds from the refrigerator every second day and allow
them to come to room temperature.  They are then returned to the
refrigerator.  This is of course to imitate the warming up cycle in spring. 
I keep this up for about a month, leaving the seeds out for increasingly 
longer periods of time. If germination doesn't begin within 3 months after 
the seeds are kept constantly at room temperature, try giving them another 
cold treatment. I use this treatment though for just about all of my seeds 
that I sow in the refrigerator, not just the ephemera's. 

SEEDS THAT NEED TO BE DRY STORED BEFORE SOWING:  Many, many seeds respond
well to being dried out before sowing.  The theory is that either they don't
have mature embryos when they leave the plant, or that there are chemical
inhibitors that break down as the seed ages.  According to Norm Deno, with
these seeds, there is an optimum storage time.  Seeds sown fresh often won't
germinate at all, but if they are stored for a few months, they will
germinate easily.  If they are kept in storage too long, they will eventually
use up all their stored food and die. Norm suggests that they be stored for
approximately 6 months, but I never really pay much attention to storage
time. I collect seeds as they are ripe, dry them by leaving them in thin
layers in a old butter carton, then clean, package and store them until I'm
ready to sow.  If I collected them in early summer they probably do get
six months storage, but any later and I'm sure they get less. This general
rule applies to nearly all of the popular sun-loving garden plants and
grasses. For clues, look at the plant. Does it hold it's pods upright, or
retain it's seeds for a long time after the capsules are open? If so, it
probably will respond favorably to dry storage.  The seed of all the common
garden vegetables, most herbs, and probably 90% of the annual flowers fall
into this category.

Dry stored seed is usually dried for a week or so in the open air. I've
heard some people recommend that you leave them out the sun, but I don't.  I
simply spread them out in thin layers and allow them to air dry in a room
with good air circulation. They are then cleaned and packaged into paper
envelopes (properly labeled and dated of course) and placed in a seed
collection box.  If I have leftover seed after I get done sowing the seed in
winter, or early spring, the remainder are moved to cold storage, to maintain 
as much viability as possible. I place the packets in ziploc bags and put them 
in the refrigerator. Do not try to force all of the air out of the bag, as the
seeds need to have air, and the air will keep you from crushing them with a
milk carton. 

Now do I sow them at room temperature, or do I start them in the
refrigerator.  By far, the largest number of popular garden plants can be
started easily in warmth.  There is, however, no easy way to tell which ones
need a cold period. If I simply have no idea, I try to make a guess as to
the time of the year the plant sets seeds (assuming I don't know). If it
sets seed early on in the late spring or summer, it is probable that the
seed won't be harmed by warm temps, and will probably germinate in warmth,
so I start them at 70F.  If the plant sets seed later on, it is likely that
either the plant needs a cold period first, or will at least not germinate
readily at room temperature. Sometimes it can be harmful to sow seeds warm.
If the plant's seeds would not fall on warm soil in nature, don't try
starting them that way. Try the cold period first.  In general, if I don't
know, and the seed is valuable I always start with a cold period. You are
less likely to kill the seed this way.

IMPERVIOUS SEED COATS:  These are most often found in seeds of the pea family
(Fabacaea), but may be found elsewhere on occasion, especially in plants
that evolved on prairies where they would be subjected to annual fires.
These seeds are usually dry stored prior to sowing, but it doesn't really
seem to matter. On the whole, these seeds are longer lived than most of the
other types. I've germinated seeds of the Golden Chain tree (Laburnum) that;
were 12 years old.  

Usually, the only trick to germinating this type of seed is to corrupt the
seed coat enough so that water can get in, without tearing up the seed.
(There are a couple of exceptions, one is Opuntia, and the other
Leucocrinum, both natives of the Western US, there maybe others as well.
These seeds also need a cold treatment.) With large seeds, like morning
glories, it is a simple procedure to clip off a piece of the seed coat with
a pair of nail clippers, or make a small pinprick with an exacto knife. 
Smaller seeds can be rubbed against some sandpaper glued to a board.  
Both of these methods will work, although I don't use the sandpaper one. 
The seeds are often too damaged to live. If you dampen a towel and then sprinkle 
the seeds you'vetreated in it and hold for a couple of hours, the ones that 
are ready to absorb water will begin to swell. Here are a couple of other tips. 
I haven't tried all of them.

1.  Tie the seeds up in a stocking and place them in running water (a
    dripping faucet) for several days. When they start to swell up, plant them.
2.  Soak them in a cola product until the coats are softened.  I've not
    tried this one, just read about it the other day. (credit for this to Jim
    Marshall)
3.  Place them in a small jar with some sandblasting (silica) sand, and
    shake them vigorously, or put the whole mix in a rock tumbler without the
    water and tumble for an hour. This one I've tried, and it is great for
    really small seeds like Astragalus and Sphaeralcea. 
4.  Rub the seeds against a whetting stone instead of sandpaper. You are
    less likely to damage them than if you use sandpaper. 
5.  Pour almost boiling water over them, and let stand overnight before sowing.

GENERAL SOWING INSTRUCTIONS:  I use two different methods for sowing
seed, either paper towels or seedling pots (commonly referred to as pans). 

PAPER TOWEL METHOD:  I got this method from Norm Deno, who says he got it
from someone else (Margery Ledgren). This is very easy. Take white paper
towels. Fold them in half three times. Label the towel with the variety,
date and any other information, like oscillate temps before bringing to
warmth. Dampen the towels, squeezing out most of the water. It should be
well dampened, but you shouldn't be able to squeeze more than a couple of
drops out of it. Open the towel open two folds. Sow the seeds inside. Fold
back up, and place in a thin, non-ziploc bag.

Whether you are placing them in the fridge, or not, you need to open them up
at least once a week to check for germination and allow air to circulate
around the seeds briefly.  When germination begins, move the germinated
seeds with tweezers to a seedling pot. If I know the variety well enough to
predict it's behavior, I don't wait for more than one or two seedlings to
germinate before moving them all to pots.  Some seeds, with erratic
germination, have to be moved as they germinate.  These are the main ones I
sow in towels. If you sow seeds with erratic germination in pots, the ones
that germinate first will crowd out the later ones, and if you try to prick
them out one at a time, you may end up burying the others. I also sow very
rare and valuable seeds into towels, as overall there is a better success
rate.  The only other ones I sow in towels are those needing alternating
cycles of warmth and cold. Germination is faster this way. 

You can place several towels into each bag, although you should be careful
to place seeds that actually need light to germinate in bags by themselves.
(There actually aren't very many that do. Most of the ones that light is
recommended for actually don't require it, but are very small and just
shouldn't be sown too deep or they won't be able to break the surface). Make
sure you do not put the bags in the sun, as they will overheat. I place mine
on the end of the same shelf the seedling pots are on.  Norm Deno uses a
separate method for seeds that require light to germinate, sowing the seeds
on top of the towels. I don't, I've found that they get plenty of light to
germinate through a white paper towel.  

If the towels begin to break down, or get really moldy, just transfer the
seeds to a clean towel. You will often have a little mold growing on the
towel, or internally infected seeds. Remove the bad seeds, but don't worry
too much about the mold growing on the towel. After three years experience
with this method, I can say for certain that I've only had one case of seeds
being killed by the mold in a towel, and that was some I left in the fridge
over the busy spring season without remembering to ever check them. 

Lastly, use this method of sowing only if it's necessary, or you have the
time to transplant the sprouted seeds. It is a time consuming process. And
don't use this method on dust like seeds. You can never get them loose from
the towels as the ultra fine radicles root immediately to the towel.    
  
SEEDLING POTS:  Even with a nursery, I still only use seedling pots. If the
variety is very popular, I might sow two or three, but rarely do I need them
all. I use a sterile soil mix for the medium, mixed with 1/4 to 1/2 part
coarse grit or perlite.  Rock garden plants get more grit. The pots are
cleaned in hot water and filled full to the rim.  I then dampen the pots
with a fine spray from the hose.  (Some people use a boiling water bath to 
insure sterility).  The seeds are sown directly on to the surface of the soil.  
I do not make little holes for each one. Most professional propagators don't.
We'd never get finished.  The seeds are then covered with granite grit.
Rarely more than 1/4", and just a very fine layer over seeds that are small
or need light.  Place a plastic label in the pot, or use a folder label, and
stick one to the pot. Put the pots either out of doors in a cold frame, or
indoors under lights. I don't use my greenhouse for starting because it
tends to overheat, but if you have one that has fairly even temperatures,
you could. Indoors, I mist the surface of the pots daily with a fine mister,
and water about twice a month. You'll soon be able to tell which ones need
water just by the weight of the pot when you lift it.  Keep the seed pots
evenly moist, but not constantly soaked.  

Sprouted seeds moved to pots from the towels are treated the same way. There
is no need to go about making a tiny hole for each radicle. Just lay them on
the soil. They'll find the way down. 

I do not feed seedlings in seedling pots. When the seedlings are big enough,
they are moved to individual pots, or seedling flats. Transplant them before
they become over crowded. I don't wait very long. Usually if they are big
enough for me to hold on to, and have the first set of true leaves, I move
them.  I begin feeding a mild organic fertilizer after they are established
in their new homes. You'll have to make your own choices there. I have no
suggestions as far as chemical fertilizers are concerned. I don't use them.

Above all when beginning don't expect everything to work like clockwork.
Don't give up. If at first you don't succeed with a particular variety, try
it again next year. I get better at it every year.  You will too.

I know that I didn't cover everything, but that's most of it. I wish I could
cover the plants individually, but this is supposed to be a lecture, not a
book. I do recommend that you buy one to aid you in seed germination, and
Norm Deno's Seed Germination book is the very best for garden seeds.  I'll
be happy to answer questions about individual species as my time and
knowledge allows. E-mail me at jadare@accessus.net with questions. It may
take me awhile, but I'll get you an answer if I can find one. 

Lastly for tonight, I'm taking a break from giving lectures until the
Christmas season is over, and I'm caught up with my seed starting.  The next
few sessions of my garden hour, will be open question and answer hours.
We'll take up after the new year with cuttings. Happy Holidays.  Are there
any questions?

You will find more written by me on the subject of starting seeds at
http://www.suite101.com under the heading Perennials.  
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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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