IN THE GARDEN: Bonsai azalea’s small root system makes it less winter hardy

Q I have a large collection of bonsai trees that all require some degree of winterization: Evergreen conifers and cold-hardy deciduous broadleaf trees (oaks, maples, hackberry) get mulched-in outdoors in a plant bed near a wooden fence. Other less cold-hardy, broad-leaf trees like crape myrtles will come into an unheated garage that never really gets below 50 or 55 degrees, but not until after going fully dormant first outdoors. Finally, my tropicals go to a climate-controlled greenhouse where they continue on into a kind of diminished "growing season." One tree, however, always has me wondering which option is best -- (1 or 2)? That tree is a large-leaf azalea pictured here mulched-in outdoors now [the reader sent a photo]. Keep it outdoors or garage it? Your professional opinion -- noting that my requirements would prefer a less battle-scarred tree come spring, but not at the expense of optimal health and longevity.

A If we had a crystal ball and could guarantee the weather, it would make my answer easier. I think to be on the safe side, the garage option is the best. Even established azaleas can suffer winter damage in a particularly cold winter. Bonsai plants have a more limited root system, which means less hardiness. If you have the option (and patience) to leave it outside, and move it in only in dire conditions that would work as well.

Q I recently saw your column that mentioned the beautiful autumn colors this year on Japanese maples. This one here was especially interesting in that it combines the outer leaves silvered from a dry frost followed by a rush of understory leaves blushed up after a good soaking a few weeks later [the reader sent a photo]. It made for a fascinating and different fall color scheme on the tree that I hadn't seen before.

A That is stunning. Thanks for sharing. What an interesting year for fall color.

Q Help me! I have a sick palm. I just now was able to get it in my garage, so did I kill it? Please help me to save it.

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A It looks like Yucca gigantea to me, not a palm. This yucca is not the same species as the one we can keep outside in our gardens, and this one is not winter hardy in Arkansas. It did take a hit from the cold, but I would be surprised if it was killed. Keep it in the garage for the winter and do some trimming on the damaged foliage in the spring when you move it back outside. Yuccas are pretty tough plants. It may take a bit to regain its peak performance, but it should come back.

Q I know you have told us a thousand times how to care for a poinsettias, but I do not have a green thumb. The one I got at the first of the month still has red flowers, but it is shedding leaves. What can I do?

A Make sure you aren't overwatering -- or underwatering. Overwatering is definitely more common, but both faults can cause leaves to shed. The red "flowers" are actually modified leaves called bracts. They can keep that red color for months, provided they get even moisture and ample sunlight. If the plants are in a foil wrap, when watering, remove the wrap and let the water flow through to the sink, then put it back in the wrap or place it on a tray. Let it get a little dry in between waterings. Bright sunlight or artificial light during the day is also critical. Good luck!

Q I have that white mold on two crape myrtle trees. Is it too late to apply dormant oil?

A The white "mold" is actually the crape myrtle bark scale. The insects are usually coupled with black sooty mold, which forms on the sticky excrement the insects give off. It is not too late to use a dormant oil. Pick a day when the temperatures are above freezing, and thoroughly saturate the tree. More mature crape myrtles often have peeling or scaly bark, so it is usually impossible to get total coverage with the oil, but it does help.

Retired after 38 years with the University of Arkansas Cooperative Extension Service, Janet Carson ranks among Arkansas' best known horticulture experts. Her blog is at Write to her at P.O. Box 2221, Little Rock, AR 72203 or email

 Gallery: In the Garden Dec. 17

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