Fun feature: Ask-a-GardenerBy Melody Rose (melody)
October 1, 2011
Rebeccax asks: I planted a small 'Lipan' crape myrtle in my front yard two years ago. It seems to be growing fine and blooms nicely. Just this weekend, I noticed that the edges of the leaves are turning red and then look burnt at the very edge. Also, the leaves folded inward, but not totally closed. I examined very closely for bugs and there were none. Then, I thought it might be the fertilizer I put down a few weeks ago, since the leaves looked burnt at the tips. A few days later, I looked at the crapes surrounding my church, which is close by. I noticed that many of them had the red and then burned-looking tips on them too. I wonder if this is a sign of them starting to go dormant?
Please let me know what you think is happening with my tree.
Melody answers: Most crape myrtle foliage turns reddish or maroon in the autumn. Mine is just starting to show a bit of change here in Kentucky and the image on the left shows normal color starting to develop. I took the picture just for this question, so the foliage looks like this right now. If you're not familiar with its appearance, it can look like a problem. It is possible that you may have a bit of leaf burn from the fertilizer, but it shouldn't amount to any lasting harm.As long as the tips of your branches remain alive, you should be fine. If your branch tips start to die, you should check with your County Extension Agent for local issues with crape myrtles.
Weatherguesser asks: Do plants have some kind of early warning system to anticipate early/late season change? Some of my trees seem to be dropping leaves (London Plane, Birch, Liquidambar) or changing colors (Liquidambar) earlier this year than in past years. I understand that plants sense the regular rhythms of the seasons, but can they sense, in advance, when those rhythms are going to be shifted? By the way, I live in Zone 9B (Sunset 15), a pretty strongly marine-influenced climate with few major changes from season to season. Early fall (late Sep-early Oct) and mid-spring are usually our warmest parts of the year, with the rest of the year generally being moderated by land-sea breezes so it gets neither very hot or very cold. So I'm wondering why my trees are getting into fall mode a month earlier than "usual". I've lived in the same town for 21 years now, and in the same house for 6, so I'm pretty attuned to what constitutes "usual". I'm also a meteorologist by training, although not really active in the field professionally since I've been here. Still, I'm pretty much aware of the weather patterns here. This has been a mild, but unexceptional summer, following an unusually rainy winter last year (about 160% of our normal water year). So I'm just curious. Has any research been done on this?
Melody answers: Stress plays a part in the development of fall color and I'm guessing that your rainy winter may be the culprit. Even though you indicate an uneventful summer, the events earlier in the season set the stage for an unusual cycle. The trees you mention, are some of the earliest to show color in my area (Kentucky) and are the first to display any deviation from the norm. Although I'm not familiar with your climate, things like ice storms, late freezes or even early leaf-out affects the timing of my color show. Color develops when the tree quits producing chlorophyll, so any changes during the season might jump start the process. Several studies indicate drought brings on early fall color, but I'm not able to determine if experts suggest excess moisture does as well. However, all experts agree that stress is the main factor in early color.
Polly20 asks: The corkscrew hazel or Harry Lauder Walking Stick; could I plant one in October? And what are the best conditions for its growth?
Terry answers: In many parts of North America, fall planting is preferable to spring for many perennials and woody shrubs and trees. Soil temperatures are warmer than in the spring, and the plant will have several months to settle in before the heat of summer begins. However, you are from Halifax, Nova Scotia, and the average first frost for your area is October 20, which makes October planting risky at best. Soil temperatures should be at least 50 or warmer when you plant trees and shrubs (warmer for conifers). Once you begin experiencing regular frosts, your soil temperatures will drop, even though snow is still a ways off.
If you are choosing a plant from your local nursery, what condition is it in? To successfully survive the transition, its root system should be well-established and the plant should not be recovering from a stressful, hot summer. The end-of-year plants at your local nursery may not be in ideal condition.
Speaking from personal experience (I killed three Corylus 'Contorta' plants before finally getting one to take hold, only to move away and leave it behind), they are a little picky, especially in their first year of growth - adequate moisture and nutrients, and well-draining soil are musts.
Bottom line: if you have a perfectly healthy specimen from your local nursery, it would be better to plant it sooner than later, but you are rolling the dice by planting this late in the season. Good luck!
Mssudie asks: I've been growing 'Hot Chocolate' calla lillies for several years now and I've never done anything to them. However, this year they were not as tall and seemed to be crowded together. Should I be digging the plant up in the fall and separating the roots? I just planted them when I bought them and they have grown beautiful every year. Help
Sallyg answers: Sounds like your 'Hot Chocolate' callas are thriving. Callas, like daffodils, arise from bulbs. Like daffodils, happy callas will form more bulbs each year, and can become crowded. Crowded leaves and smaller leaves and blooms are classic symptoms of crowding. Yes, they should be divided, and you can do this in the fall in your area. Wait for leaves to start yellowing. Then lIft the clump, gently shake off the dirt, and separate the bulbs. Discard any that were damaged in digging (I usually spear a bulb or two when I dig!) While the hole is open, loosen and enrich the planting area with some compost or aged manure if you have it. Replant the largest, healthiest looking bulbs. Pacific Callas recommends that you replant them 4 to 6 inches deep and at least a foot apart. This sounds to me like a very generous spacing, and should keep those bulbs happy for several years. If you wish, you may save those bulbs indoors over the winter. Let them dry (but not in the sun) for a few days and then store them in a dry, warm (50 to 60 degrees) location. Enjoy! Callas are a unique and surprsingly easy summer bulb flower. Here is Pacific Callas webpage on calla care.
hissong4us asks: I have a Butterfly Bush that's getting very big and need to prune it down a bit. Is there any special considerations to cutting back this type of Bush?
Carrielamont answers: Well, lucky you! (There's a picture of an actual butterfly attached.) The general rule for this type of bush, in colder areas (I see you live in CT), is to cut it down to about one foot from the ground while it's dormant, ie late fall, winter, or early spring. I didn't do that with my bush this year -- I guess I felt that would be cruel as it had only been there for a year or two. Now, I have the same type of situation as you do, scraggly blooms, branches growing every which way. This fall or next spring I WILL CUT IT BACK! Some sources suggest mulching what's left; other people suggest waiting until early spring so you don't need to bother with mulch. Many of my articles have mentioned how it is often a kindness to cut a plant back by a third. With buddleia, you and I need to go much farther and take it nearly down to the ground. Buddleia blooms on new wood, so make it all new wood. Incidentally, the trimmings can make new bushes, I am told, just stick thin branches (about as thick as a pencil or drinking straw) into a nursery pot of soil and they will form roots. Another gardener suggests using the leftover sticks as stakes elsewhere in your garden - she uses hers to stake peas. Good luck, and Happy Gardening.
Remember, if you have a gardening question that you would like to suggest for this feature, post it here. Our writers and admins will handpick a few of your questions and answer them in an upcoming Ask-a-Gardener, one of our Saturday morning features. Other questions may be moved to one of our other forums so your fellow members can help you.
A special thanks to member 'growin' for his lovely images of the Corylus 'Contorta' (Harry Lauder's Walking Stick) and the Zantedeschia (calla lily)