At 10:12 PM 4/27/03 -0400, Dante Catoni wrote:
I am just starting out in bonsai. I would like to grow some trees from
seeds. I purchased some acer palmatum, Chinese zelkova, and giant sequoia
seeds. The instructions for the maple say to cold stratify for 120 days.

Acer palmatum seeds need this cold moist pretreatment, Zelkova will
probably give you a more even germination with it, but 30 to 60 days should
be enough, not sure about Sequoiadendron gigantea, but it probably needs
it. Starting it now will means that you won't be sowing until the first of
August, which is probably too late for a trouble free overwintering. I try
to start my pretreatment period as early as possible so that I am sowing in
April and May. If you haven't soaked the seed yet, you can keep it stored
in the refrigerator until next year, but expect a lowered germination rate,
especially for the Acer palmatum.

If you bought the A. palmatum seed from a company and it came dry, it is
probably worthless anyhow. Dried A. palmatum seed enters a deep dormancy
that can take several years to break, if at all. It should be pretreated
fresh in the fall immediately after it is collected and sowed the following
spring. It is very difficult to store. There are very few companies that
will tell you this, they are more interested in getting your money. Some
seed cannot be stored at all. Red Maple, Acer rubrum must be planted fresh
from the tree in the spring as soon as the seed ripens. If it dries, it is
dead, but I see it listed all the time from many seed companies.

You have a problem, that's for sure. For the A. palmatum, do this: Soak it
and put it in the fridge. Take it out around the first of August. If none
of it has germinated (viable seed will germinate while in the fridge),
leave it in the dark around 70F for three months for a warm moist
pretreatment, checking to make sure it doesn't dry out. Pray it doesn't
germinate, it probably won't. If any does, take those out and plant them.
At the end of three months, put it back in the fridge and keep it there for
the winter, sow new spring.

For seed that germinates this summer, but is going to have a reduced
season, keep it growing as long as possible into the fall. This means
protecting it from freezing. At some point in midwinter, probably when
protecting it becomes too difficult, store the plants at 30 to 40F for the
winter. If you can't find a place to do this, simply put them in the
refrigerator. They don't need light, and they don't have to be dormant
before placing them in there. Keep them there until danger of frost is gone
next spring. Check weekly or so to make sure they aren't drying out.

If
I start this process now what should I do for the first winter? Will they
survive outside with the proper protection or should they stay inside? I
could keep them in my garage which won't go below about 40*. Also, I've read
that giant sequoia are difficult to grow. Why is that and what special care
do they need?

I gave up trying to make bonsai from this species, S. gigantea. It resents
root pruning, dies back a lot and just doesn't seem to want to grow well in
our hot inland valleys. It also gets a fungal blight at lower elevations,
but I don't know if this is a problem elsewhere. On the other hand, its
cousin Sequoua sempervirens, Coast Redwood is excellent bonsai material and
a lot easier to grow. Foliage is similar but not the same. I just don't see
any point in torturing myself over S. gigantea.

Can I start all the seeds in bonsai soil? I made a mixture
today of fir bark, perlite, and sphagnum moss following the recommendations
of Brent Walston on www.evergreengardenworks.com

Yes, this is what I use to _sow_ my seed, but for pretreatment in the
fridge, I use vermiculite. Here is a very easy and foolproof method of
getting just the right amount of moisture and almost zero mold and fungal
problems: Soak the seeds at least overnight by pouring hot water over them
(about 120F). Pour off, rinse and repeat a second day for seeds that deeply
stain the water. After this, rinse and pour off all the excess water. Let
it sit for several minutes and try to get more water out. When no more
water will come out of the seed, mix it with an equal volume of DRY
vermiculite. Thoroughly mix in a ziplock bag and place in the fridge.
Normally you will not have to add any more water during the three month
period. The vermiculite absorbs all the surface moisture, greatly reducing
mold growth. Vermiculite itself will not mold like peat moss because it is
a mineral. The absorbed water acts as a moisture reservoir. The seed must
be thoroughly soaked for this to work well. It is the moisture _inside_ the
seed that is critical, not the moisture in the medium. You just need to
keep it from drying out.

At the end of the pretreatment period, or when the seed germinates, take it
out and sow it in a mixture similar to the above. There are two basic
methods of starting seeds. One is to use cell type pots. These are usually
about an inch or two across and about two inches deep. This allows each
seed to develop its own rootball and makes transplanting a breeze.
Transplant when the seedling forms an intact rootball, which usually takes
about two months, so you are doing this in summer and must give it proper
care to avoid heat stress.

If you are not in a hurry, sow the seed in a flat. This allows you to put a
much greater number of seedlings in a smaller space. Let them grow through
the summer in a sheltered environment and don't transplant until dormant in
winter. You don't even have to transplant all of them the first year. I use
those seedling flats to store plants for several years. Since they are so
crowded and in such little soil, they stay nice and small with tight
internodes, just what you want for bonsai seedlings. I can get several
hundred seedlings in an 18 x 18 inch flat.

For a number of years, I was real big on cell flats, but more and more I am
going back to my old method of using flats. I haven't done any actual
quantitative studies, but it seems like more seedlings survive in the
flats, and the quality of the trees is better. I still use cells for
special cases like acorns where I prune off the seedling radicle to remove
the tap root and improve the root system. This results in a lot of seeds
dying, but the survivors are much higher quality. After a couple months, I
take the survivors out of the cells, examine the roots, prune again if
necessary and repot into 2 3/4 inch pots. They take off really fast with
this process.


Brent in Northern California
Evergreen Gardenworks USDA Zone 8 Sunset Zone 14

http://www.EvergreenGardenworks.com

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