Summertime favorite tropical plant can spend winter
indoors as houseplant
Is it possible to overwinter a white mandevilla in an
unheated garage? If so, should it be cut back or left intact under
a hotcap? They are trained to pyramidal trellises and potted in
natural terra cotta.
Temperatures below 50 can damage mandevilla. Anything below 40
will probably kill it. It also needs lots of light to remain
healthy, even during its winter growth stall. So overwinter it in a
warm sunroom -- 70 or warmer by day, minimum 60 at night.
Water it whenever it dries. Test for dryness by hefting the pot
to gauge its weight or pushing one finger into the soil to see if
it's warm and dry an inch below the surface. It will probably need
water far less often indoors in the lower light of a house in
winter than it did outdoors in summer. The reason you should be
careful about watering is the same reason you should use tepid
water and avoid placing the pot on cold tiles or sills -- soggy or
cold roots cause leaf drop and other problems in mandevilla.
Mist it daily or grow it near a humidifier to keep its glossy
foliage healthy. Guard against mealybug, mites, scale and whitefly
by bathing the foliage often. Don't expect any bloom during
Cut the plant back late next March, leaving only the sturdiest
vertical shoots and shortening all side branches to just a few
If you treat it very well over winter it will resume blooming
next June on the new wood that forms after your pruning.
A great way to learn how to overwinter special plants is to
visit garden centers that stock such plants year-round.
Hooray for diversity in ash tree
S.P. writes, "I just finished planting replacement trees
for the 30 ashes we had to remove here at the retirement community
where I work. I planted only 13, which was enough because the
grounds had been overplanted to start. I am excited about the trees
because I was able to plant ginkgo, American yellowwood, goldenrain
tree and, my favorite, an awesome dawn redwood. Thanks for your
advice to diversify, it has produced good results and my residents
Green thumbs up
to preserving a few ash leaves for posterity. Because of the
apparently unstoppable emerald ash borer, the clear gold or
butterscotch of green ash and smoky wine of white ash foliage in
autumn may become only a memory, all within our lifetime. Pressed
ash leaves may one day be as precious as passenger pigeon
Green thumbs down
to landscape professionals who aren't. Your shoddy and ignorant
work makes me ashamed for the whole industry and treats your
unsuspecting and trusting customers as badly as the plants. Be a
real pro! Take a class, read current articles in journals or at
university websites and learn how to plant so trees will thrive,
not simply survive a warranty period.
Originally published 10/18/03