Knowing When to Come in from the Cold
by Brad Thompson
This article is about when and how to bring your begonias
back indoors for the winter. It is in two parts. Part
one will be tips for Northern Growers who have no choice about
whether to winter their begonias indoors. Part two will be tips
for Southern Growers who may choose to do as the Northerns do or
prepare their plants for a winter outdoors. There is no one
method to follow when growing begonias or for how you winter them or
bring them indoors. This article is to give you information and
tips so you can formulate a plan that works for you and your growing
conditions.
Part One: Northern
Growers.
Northern growers have the added hardship of having a
limited growing period when their plants can grow outdoors.
You can choose to do 2 things; you can leave your plants indoors all
year or you can grow them outdoors during the warm months and bring
them in for the cold ones.
Some of you may choose to only bring cuttings indoors
after the summer. This has a plus side and a down side. One
is you can save space by restarting new plants each fall from cuttings
but if the cuttings fail then you have lost the variety. You can
avoid some of the risk if you plan ahead. Most of you know
when the first frost will usually come for your area. You should
start your cuttings started well in advance of that first frost
even before you have to start using the furnace. You'll have more
of a chance of success. You'll give the newly rooted plants plenty of
adjustment time. You'll also have a chance to try again before
losing the original plant outdoors by taking more cuttings if you have
a problem.
Plants started early before the furnace starts running
full time will have time to adjust to the lower humidity associated
with forced heat. Cuttings taken from the cold, damp fall and
rushed directly into the warm, dry indoors will be shocked for
sure. Fall is a time when generosity can help you out too.
If you start sharing cuttings with friends you can think of it as
banking your begonias. If something were to happen to yours
you'll have a source for retrieval. You might even convert a few
friends to begonias and gardening. You don't have anything to
lose. If you bring your plants indoors, you'll probably still
have to do some trimming and if you leave the plants outside they're
going to freeze anyway.
If you decide that you really want to bring the entire
plant in instead, you still need to plan ahead. You can't just
wait till you think it's going to freeze and then rush them
indoors. They need to adjust just the cuttings would and
gradually is best.
If you plan on bringing the entire plant back in every
year, you should just plan on leaving the begonias in pots to begin
with. Pots can be set in beds with plants around them to disguise
the pots and make them appear to be planted in the beds. Or you
can arrange the pots on shelves or a decorative display. The
reason for keeping them in the pots is that it will be less stress on
the begonia. If you plant in the ground, they have to go through
being yanked out of the ground, having their tops trimmed and then
going into a totally new environment. The potted plants may need
some trimming back and maybe a few cuttings taken for insurance but
they can basically be inspected for pests and then just brought back
in. Whether the plants are in pots or in the ground, you still
need to bring them in early just like with the instructions for the
cuttings.
Plants in the ground will be more work, but the advantage
is that in the ground your plant may have grown many times faster than
it would have in a pot. The disadvantage is that you're going to
have to trim the tops back to match the size of the rootball. You
have to remember that the begonia might have had several feet of roots
supporting that big plant. You can't expect to just dig it up
with only a fraction of the roots, stick it in a pot and not have it go
into shock. The lesser roots can't usually keep up with the water
required for all that top growth. It isn't so bad though, you can
root those extra cuttings and have either spare plants or backup plants.
Some plants may still require some extra help to adjust
and recover. If you grow under lights you can accomplish this by
tenting your light stand to keep the humidity in. You may want to
do this even if your plants stay in all year. It does cut down on
watering, and the plants grow lusher. Make sure to use non
flamable plastic film and make sure it isn't directly touching the
light fixture. Clear plastic will allow you to see the plants
even when covered. I also use trays filled with large perlite or
gravel to set the pots on. This will give the water somewhere to
go when watering. It will also raise the humidity if kept moist
continuosly. If you only have a few plants or don't have a light
stand, misting them frequently or placing them in an old aquarium to
keep the humidity in will help. You can gradually remove the
cover of the aquarium to adjust them to growing outside it.
When I grew in Iowa, I had an old redwood pinic table with
two benches. In the summer the picnic table was a picnic table
but during the winter it became a light stand. I would place it
in front of an appropiate window with one of the benches on top.
This gave me an area for growing plants in natural light. I hung
a florescent fixture under the table and enclosed the table legs with
plastic film. This gave me my florescent light growing
area. I kept everything from geraniums to begonias through the
winter under that redwood table.
I even grew a B. 'Sophie Cecile' under there, but at the
time, being ignorant of begonias (I might still be ignorant) I thought
it was some tropical species since it wasn't named. I was very
impressed with it and at the time had to save for awhile to buy
it from a local greenhouse. I looked at it for a month and
drooled over it before I had the $20 or whatever it cost. I had
never seen anything so exotic looking before. Even then I tried
crossing it with semps, the only other begonias I'd seen. I
wasn't successful but I remembered my experiences a few years later
when I ran into a cane begonia again here in California. It was a
B.'Pink Jade' at a swap meet. I couldn't pass it up since it was
$5 and bigger than that B.'Sophie Cecile' I'd had years before. I
thought again I had really gotten a deal. I guess I did since it
led me to the Begonia Society.
Part Two: Southern Growers
Many Southern Growers will be following some of the
methods above, especially if they don't live in frost free areas.
Likewise, many Northern Growers with be able to use some of the
Southern tips to help them preserve struggling plants.
Besides having a much longer growing season overall, southern
growers in some areas are even able to keep their begonias outdoors all
year round. Even in those areas, there are some precautions and
procedures that can be taken to assure the plants will survive the
winter. In most southern areas, although it doesn't freeze often
or ever, they still have to contend with cold, wet weather. As
most of you know, cold and wet are two conditions begonias hate with a
passion.
So, what can you do about it? One procedure that I
practice in my yard , I'll call "crop rotation". As the seasons
change and the available light changes different begonias are moved to
take advantage of the best light. In the winter, more delicate
varieties are moved either into areas that have good winter light or
that are more sheltered. Since the only way you can solve the
"cold" problem is by constructing a greenhouse most of you will have to
settle with solving the "wet" problem. Begonias can stand cold
temperature much better than they can stand wet feet. Sensitive
begonias can be moved under awnings or porch roofs, etc. to keep them
from excessive rain. Some growers even go so far as to cover
their shade houses with plastic sheeting. That will keep all the
begonias dry. You will have to consider what your neighbors will
say when it happens that you are standing outside watering your
begonias in the pouring rain. If you choose to totally enclose
the shadehouse with plastic, including the sides, you'll have to take
into account that there will be warm winter days. Your winter
enclosure probably won't have heat or cooling. I would suggest
leaving at least one side open or that you can close at night or on
cold days.
Many growers don't have the option of covering or rotating
because of limited space or limited time. Those growers have no
choice but to just leave the begonias where they are. There are
still things you can do. The most important thing is correct pot
size. Do you have any plants that seem to stay wet all the
time? Those plants are either over potted or root damaged or
both. If they're staying too wet now just imagine how wet they'll
stay this winter in the rain. Now is the time to correct the
problem before it gets worse. Gently lift the plant out of its
pot. You will see that some or most of the soil stays in the pot
or falls off the plant when you lift it out. This shows you the
plant is in too large a pot or that the roots have died to the point
that they don't hold the soil together anymore. In the spring,
when you are moving plants up to larger sizes, it's expected that many
will be growing into those larger pots. During the winter,
however, these plants will only decline furthur. The solution is
to remove all the loose soil from the plant. Once the soil is
removed, find a pot that is only slightly larger than the remaining
rootball. Replant the begonia into the new pot. Next spring
you will usually find the plant fully recovered and ready to move back
up to a larger pot again.
If you live in an area that has an ocassional frost some
years, you should have precautions ready. Many growers save old
sheets to cover the plants with if a frost is expected. Some also
save large cardboard boxes to totally enclose plants with.
Plastic sheeting can be used but if you also have rain, you can break
plants. Plus, when the sun comes out, many plants can be burned
by the heat through the plastic. A newer innovation is a type of
plastic that has microscopic holes in it so it allows air, heat and
water to pass through it but still protects from frost. I've
heard from growers that have used it, that said they were able to keep
the covering on for a couple of weeks without the daily removal and the
plants were fine. This would be a big benefit over the other
coverings which you will have to remove during the day and replace
every night during cold spells. I can't tell you the exact name
of the plastic but it is available from most mail order seed companies,
such as Parks Seed.
Though I haven't tried this myself, I have heard from
growers who live in areas with some frost, that trim back their
begonias and mulch heavily with straw or a similar mulch. If you
have found that you live in an area where the frost is just enough to
completely freeze most begonias, you might try the mulching. You
wouldn't have anything to lose. When you trim back the plants,
the cuttings can be taken indoors for the winter. The roots can
remain in the ground under the mulch.
With all the different variables across the country, I
can't specifically tell anyone exactly what will work in their
area. The suggestions above are to help you experiment in your
yard to see what will be successful for you. I would appreciate
e-mail from anyone that would like to share their winter experiences
for future reference. Use the e-mail link on the home page.
