By Brian Gershuny
http://home.comcast.net/~okamigardens/
Sorry
gang, it’s that time again. Autumn is
upon us and Winter looms just over the horizon. For us cold weather folk, this means lots of preparation to get
our little trees through to Spring. Let
me preface this article by telling you I grow non-tropical trees near the New
Jersey coast, zone 7, where the Winter
temperatures drop occasionally to 0○ but daytime averages 30○ - 40○. Adjust your setup for your local
temperatures. I just visited the
Northern California coast where things don’t freeze. I’m very jealous.

First
lets talk about Autumn. Enjoy it! The cool days and beautiful colors. It’s what we wait for all summer. Take lots of pictures. It’s also time to take a ‘head count’. If you’re like me, your collections grow
when you’re not looking. Start thinking
about a place to over winter them. Your
options depend on the size of your collection and available space.
Why do trees need winter
protection? These are temperate trees
that have evolved to survive very cold winters. The problem is you have changed it’s environment. Trees in nature have roots that go deep into
the ground where there is no freezing and constant moisture. A 2-4” deep bonsai pot freezes and
dries. What you want to prevent is the
recurring freezing and thawing. The
answer is insulation (we’ll discuss that later). Evergreen trees need some light but deciduous trees can be in
complete darkness.
The ideal
situation: A large temperature
controlled greenhouse with lighting and a water supply. (Dreamy harp music
plays) OK, back to reality! If you have the room, a cold greenhouse or
hoop house is great. They are
affordable and come in various small sizes.
Some have automated temperature vents so it doesn’t get too warm. Keep in mind, the smaller the greenhouse the harder it is to maintain an even
temperature which is your main goal.
Use white plastic or white coated panels to keep the daytime
temperatures down. Remember, you don’t
want it warm – you want it even.
If you don’t have room for
a greenhouse you need to be innovative.
Here are some method that I and other people I know have used. The most important thing is protection from
cold drying winds and keeping the root temperature as even as possible. Old pictures from Japan show panels of
bamboo and reeds to make lean-to’s or against buildings. The principle still works.
Indoor
storage:
People
have kept trees in sheds, garages, outbuildings and even refrigerators. This is fine for deciduous trees that do not
need light. Just remember to water
them. Screened in porches are
great. Provide a little windbreak for
extra protection.
Some
people have used their benches wrapped in white plastic. I found it better to move the benches to the
east side of the house. You also need
to open it frequently to water and maintain the temperature. It works but is somewhat inconvenient.
MULCH! Key word. Bury your trees in some type of mulch to
keep the roots and pots at as even a temperature as possible. Bark, liquorish root, ground leaves, salt
hay or pine needles are all fine. I
have cut a slit in bags of mulch and buried the pots into them. Bury the trees almost to the lowest
branch. Use mulch in your greenhouse
too (unless it stays above 35○). I throw a few moth balls in there too. Insects and rodents can destroy your
collection in no time. I also spray my
trees (especially Junipers) a week or two before I put them away. Mulch, mulch,
mulch!!
When
to put them away:
When it’s cold!
For me it’s mid to late November.
One year winter came early so I hustled to get the trees put away
early. No magic number or dates. There are still some autumn chores like
pruning some deciduous trees and pulling Black pine needles. I put the pines away last. That is the last chore I want to do, usually
in December.
Can trees stay outside? A resounding maybe. Many
can and in my nursery, many do. I have
hundreds of trees and a 10 x 16’ hoop house.
No modern math here. The tiny
and sensitive trees go in the greenhouse.
The others are put on the ground under benches with pallets leaned
against them and near the fence, buried in leaves. I push all the nursery cans together and rake leaves up against
them.
During
the winter. Make sure the trees do not
dry out! I cannot stress that
enough. Check them at least once a
week. If they freeze, check them in the
afternoon as it is most likely to be defrosted. Then get some water. Keep
the mulch moist, too. Key word is
moist. If you make them wet, when it
freezes your pots will crack. I loose a
few every winter. Some people that have
very expensive pots repot the trees, without disturbing the roots, to a larger
mica pot for winter.
What not to do during the winter:
Don’t bend or wire the branches. They break and die. Don’t repot. All the tree’s food is stored in the roots. If you cut them off now the tree may not
leaf out in spring.
What to do:
Rest. Your trees are resting, you rest, too. Read some books and articles for
inspiration. Order catalogs. Travel and look at trees in the wild. Build more benches for your growing
collection (you know it will) Enjoy the
winter. It’s a beautiful time of year.

Brian
9/04
B.G.