Posted on
Thursday, September 27, 2007
Thursday, September 27, 2007
Problems With Texas Mountain Laurel Solved With Trimming
DEAR NEIL: What is wrong with my Texas mountain laurel (photo attached)?
When a plant's tissues divide in two directions (height and length in this case) instead of three, that growth is called "fasciation." There are species of cactus and euphorbia that do this, but the most common examples are celosias (cocks-comb). This is not uncommon with mountain laurels and it presents no special concern. Trim them off by cutting back into normal growth.
DEAR NEIL: We have had our magnolia tree for several years during which time it has doubled from 6 to 12 feet tall. Still, no flowers. Why?
That is very normal for young flowering trees. They spend their first several years establishing good roots and top growth before they commit to flowering. It's the same with animals - they, too, have a juvenile phase before they are capable of reproduction. Be patient.
DEAR NEIL: Is there any hope for redtip photinias with the maroon spots on their leaves? We have lost several and hate to buy more if they're doomed.
This is a horrible disease for which fungicides seem to offer no control. Most professionals quit using it some time ago. Other plants will serve you better.
DEAR NEIL: Round Up has not controlled nutsedge in my beds. What would you suggest?
Use Image or Manage. They operate similarly. Both need to be applied during the hot weather of June, July or August. Nutsedge will be going dormant soon. These are primarily for use in turf, but they can be used around many ornamental plants as well. Read and follow label directions carefully.
DEAR NEIL: I have a weedy grass growing in my red yuccas. How can I get rid of it without being stabbed in the process? It's grown exponentially this year.
Spot-treat with one of the glyphosate herbicides. Use a piece of cardboard as a baffle to keep the low-pressure spray from drifting onto the red yucca's leaves. This group of weedkillers is not active in the soil so there is no fear of contamination. You might also look at the labels of various fusillade products to see if they could be used around the red yuccas.
DEAR NEIL: Why would the leaves of my potted hydrangea plant turn brown around their edges, then fall off? They did so well all spring and early summer.
Hydrangeas use copious amounts of water just to maintain all that large foliage. Browning around the leaves' edges suggests that they have gotten too dry at least once. It's common for plants that have wilted badly to drop many of the affected leaves soon thereafter. Poinsettias are the classic examples. Keep your hydrangea more uniformly moist next time around.
DEAR NEIL: I really need to know if my house's foundation is at risk. I have three crape myrtle trees planted close together. They are 18-24 inches from a bay window. There are no signs of problems but the trees are very tall.
Crape myrtle roots will certainly take moisture from beneath a foundation, but that can be replenished with a soaker hose. Their roots will never be large enough to crack the foundation. If you are concerned, however, you can always cut a trench alongside the house and put a root barrier fabric 15 to 18 inches into the soil.
DEAR NEIL: My cast iron plants' (aspidistra) leaves turn yellow. The plants are grow very slowly. What is wrong?
Probably nothing. I have many of them and they put out only 8 or 10 leaves per clump per year. The older leaves yellow and must be trimmed away every couple of months. Be sure, however, that the leaves aren't yellowing from exposure to sun. They must have shade.
DEAR NEIL: Would MSMA applied by a lawn care company cause a healthy red oak to turn brown two weeks later?
Not if it's applied correctly. However, that is a coincidence. Talk with your lawn care company. Ask, too, if there might have been any other type of herbicide in the tank. Check the trunk of the tree, too, to be sure there is no injury of any kind from sunscald, mower, trimmer, etc. Your photo didn't show any, but you may need to look more closely.
DEAR NEIL: What would cause the leaves of my well-established ruellia plant to turn tan and fall off. Now there are only a few at the tops of the stems. They've been moist. Might it have been too wet this year?
Your photos look like plants that might have stayed too wet for an extended period, so this year's rains may have been at fault. Look at the backs of the leaves to see if there is any evidence of lace bugs or other pests.
That doesn't appear to be the issue, but ruellias just don't have many problems.
Have a question you'd like Neil to consider? Mail it to him in care of this newspaper or e-mail him at mailbag@sperrygardens.com. Neil regrets that he cannot reply to questions individually.
When a plant's tissues divide in two directions (height and length in this case) instead of three, that growth is called "fasciation." There are species of cactus and euphorbia that do this, but the most common examples are celosias (cocks-comb). This is not uncommon with mountain laurels and it presents no special concern. Trim them off by cutting back into normal growth.
DEAR NEIL: We have had our magnolia tree for several years during which time it has doubled from 6 to 12 feet tall. Still, no flowers. Why?
That is very normal for young flowering trees. They spend their first several years establishing good roots and top growth before they commit to flowering. It's the same with animals - they, too, have a juvenile phase before they are capable of reproduction. Be patient.
DEAR NEIL: Is there any hope for redtip photinias with the maroon spots on their leaves? We have lost several and hate to buy more if they're doomed.
This is a horrible disease for which fungicides seem to offer no control. Most professionals quit using it some time ago. Other plants will serve you better.
DEAR NEIL: Round Up has not controlled nutsedge in my beds. What would you suggest?
Use Image or Manage. They operate similarly. Both need to be applied during the hot weather of June, July or August. Nutsedge will be going dormant soon. These are primarily for use in turf, but they can be used around many ornamental plants as well. Read and follow label directions carefully.
DEAR NEIL: I have a weedy grass growing in my red yuccas. How can I get rid of it without being stabbed in the process? It's grown exponentially this year.
Spot-treat with one of the glyphosate herbicides. Use a piece of cardboard as a baffle to keep the low-pressure spray from drifting onto the red yucca's leaves. This group of weedkillers is not active in the soil so there is no fear of contamination. You might also look at the labels of various fusillade products to see if they could be used around the red yuccas.
DEAR NEIL: Why would the leaves of my potted hydrangea plant turn brown around their edges, then fall off? They did so well all spring and early summer.
Hydrangeas use copious amounts of water just to maintain all that large foliage. Browning around the leaves' edges suggests that they have gotten too dry at least once. It's common for plants that have wilted badly to drop many of the affected leaves soon thereafter. Poinsettias are the classic examples. Keep your hydrangea more uniformly moist next time around.
DEAR NEIL: I really need to know if my house's foundation is at risk. I have three crape myrtle trees planted close together. They are 18-24 inches from a bay window. There are no signs of problems but the trees are very tall.
Crape myrtle roots will certainly take moisture from beneath a foundation, but that can be replenished with a soaker hose. Their roots will never be large enough to crack the foundation. If you are concerned, however, you can always cut a trench alongside the house and put a root barrier fabric 15 to 18 inches into the soil.
DEAR NEIL: My cast iron plants' (aspidistra) leaves turn yellow. The plants are grow very slowly. What is wrong?
Probably nothing. I have many of them and they put out only 8 or 10 leaves per clump per year. The older leaves yellow and must be trimmed away every couple of months. Be sure, however, that the leaves aren't yellowing from exposure to sun. They must have shade.
DEAR NEIL: Would MSMA applied by a lawn care company cause a healthy red oak to turn brown two weeks later?
Not if it's applied correctly. However, that is a coincidence. Talk with your lawn care company. Ask, too, if there might have been any other type of herbicide in the tank. Check the trunk of the tree, too, to be sure there is no injury of any kind from sunscald, mower, trimmer, etc. Your photo didn't show any, but you may need to look more closely.
DEAR NEIL: What would cause the leaves of my well-established ruellia plant to turn tan and fall off. Now there are only a few at the tops of the stems. They've been moist. Might it have been too wet this year?
Your photos look like plants that might have stayed too wet for an extended period, so this year's rains may have been at fault. Look at the backs of the leaves to see if there is any evidence of lace bugs or other pests.
That doesn't appear to be the issue, but ruellias just don't have many problems.
Have a question you'd like Neil to consider? Mail it to him in care of this newspaper or e-mail him at mailbag@sperrygardens.com. Neil regrets that he cannot reply to questions individually.

Re: Big Losses
Re: Is Obama the Right Choice?
Re: Is Obama the Right Choice?
Re: Michelle Malkin?
Re: TO THE HEIDI LOCKRIDGEs of the WORLD
Re: Big Losses
(No heading)
Re: (No heading)