Question and Answer – November 2011
If you’d like Neil’s help with your plant question, please send it AND a photo to support it by clicking here. Neil includes those questions of widest general reader interest. Here they are, as submitted by you, our readers, over the past four weeks. Remember, it will help Neil give you a better answer if you’ll include the name of the city in which you live.
Question: These Japanese yews are outside my husband’s place of work. They are not doing very well, and he’s wondering what special care they might need. D.C., no city given.
Answer: Japanese yew (podocarpus) plants do well in the eastern third of Texas, particularly east of I-35. The plant in the photo actually doesn’t look too bad. Japanese yews normally grow 6 to 15 feet tall and 3 to 5 feet wide. They’re best in morning sun with afternoon shade. They do suffer freeze damage in extreme winters, especially in the northern half of their adapted region. Apply all-nitrogen, lawn-type fertilizer to them in early spring, late spring and early fall.
Question: We bought a Shantung maple in the spring, but a few months later, it looked like it had died. The nursery gave us another one, telling us it looked like the first one had succumbed to the heat. Now, the replacement tree looks like it has died, too. We see sprouts coming up from the base. Should we cut the top off and let those shoots develop? M.G., Forney.
Answer: I’ve seen several established Shantung maples in North Texas in the past several weeks (including my own), and they handled the heat just fine. The fact that your trees were both brand new is probably a big part of your issues. They just couldn’t stand up to the furnace. However, it probably wasn’t just the heat. Each tree probably got too dry at some point, if only for a short time. It was a good choice in the first place, and it still is. I’d give it another try, even if you have to buy this one. Waiting on sprouts to re-develop would be a slow process. This is the very best time of year to plant new trees anyway.
Question: I have two junipers that are growing next to one another. One is just fine, but the other is dying. What causes this, and what can I do to prevent further dying? The same thing is happening with others just a few feet away. J. and M. B., Abilene.
Answer: This looks like old spider mite damage from earlier in the spring and early summer. Junipers are fairly susceptible, especially in years without enough rain to wash the mites away. Thump some of the declining (not dead) twigs over a sheet of white paper. If you see almost microscopic mites start to move, those are the culprits. You may still see them, but it’s far more likely that they won’t show up again until February, March or later. If you find them, treat with a general-purpose insecticide. For the record, it’s difficult from the photos to be sure that mites were the cause. The plants may just have gotten too dry. There also are several diseases that do affect junipers, but this doesn’t look quite right for diseases. Hope that helps.
Question: A friend in Louisiana is willing to give me a cutting of this beautiful passionvine. Will it grow in North Texas? How do I root it and care for it? J.H., no city given.
Answer: Hardy passionvines will grow in North Texas. They’ll usually die back to the ground in cold weather, then come back the following spring. Of course, the tropical types are not winter-hardy, so they must be kept in a greenhouse. If your friend’s plant has been exposed to hard freezes in Louisiana and if it still came back, yours should be fine. Ask before it gets any colder. I’m suspecting, from the appearance of this lovely flower, that this is not winter-hardy. In either event, here is information from the Most Asked Questions pages of my website relative to rooting cuttings. http://www.neilsperry.com/maq/general-gardening-information/how-can-i-start-new-plants-from-cuttings.html. You’ll probably be getting what would be termed as "softwood" cuttings.
Question: Fourteen years ago we decided to use Asian jasmine as a groundcover in our front yard because of the excessive shade. It’s done exceedingly well, and it still looks good. However, it doesn’t grow like it used to. I fertilize it twice a year with 8-8-8, and I mow it annually to even it up. What could I apply to get it to grow like it used to? R.M., no city given.
Answer: Pretty yard. Your problems probably lie in the heat and dry weather we’ve had. Even plants that were irrigated adequately haven’t grown as much in the temperatures and low humidity we all faced this past summer. But, the bigger issue is probably with your choice of fertilizer. You’re using a comparatively low analysis plant food, and not an especially high-quality one, either. Try a superior lawn food, preferably one that is all nitrogen, half or more of it in slow-release form. Look for 24-0-0 or 20-0-0 or something similar. Note that 21-0-0 is ammonium sulfate, and it is all fast-release nitrogen. While it’s cheap to buy, it’s extremely short-term in garden soils. Go for nitrogen, and go for quality.
Question: I have watered this area of our bermudagrass lawn regularly (at least twice a week) this summer, and it has been fertilized (not during the hottest weather). Why is it browned and thinning? B.M., no city given.
Answer: It’s difficult to tell, even though your photo shows the area perfectly. If you’re mowing really high (2 or 3 inches or even higher), the grass will produce vertical blades trying to "find the sunlight." Bermudagrass that is mowed at the proper height (1 to 1.5 inches) will be flatter, more dense and with more horizontal blades. When you mow the tall grass, you end up cutting off much of the leaf blade surface, and that leaves you with browned stem stubble for several days after each mowing. I can’t really tell from the photo what mowing height you used, but suffice it to say that tall grass quickly becomes weak grass. If that’s the case, scalp the lawn in late February. (Wear goggles and a dust mask.) It could be grub worm damage. Dig a square foot of sod by cutting it on three sides. Slide a flat spade in beneath the grass and lift it over on its side like a flap. If you find 4 or more white grub worms per square foot, they’re your culprits. They’ll be in the top 4 to 5 inches of soil. You could apply Merit insecticide now if you find active white grubs, but we’re almost at the end of their feeding cycle. Texas A&M entomologists suggest that we apply it in early to mid-summer in Texas. You might also look into bermuda mites. They’re microscopic, and they cause shortened stems and very clubby shoots. Their damage usually shows up in summer. There may be other things to consider. I’d suggest taking samples to a Texas Master Certified Nursery Professional if the problem persists next spring. I’m not sure they’d be able to see anything this late in the season.
Question: I have found this odd growth on my grass in early morning. It smells very fresh and green, and it’s very sticky and gooey to the touch. When I turn it over, it is powdery and black underneath. It turns brown when the sun hits it. I have six of them. Do I need to be concerned? D.P., Round Rock.
Answer: It’s some type of saprophytic fungus, or at least that’s what I’d guess. The black is probably spores. It’s living off some type of decaying organic matter, and it presents absolutely no concern for your lawn. I would suggest just washing it off with a hard stream of water. Or, just wait it out.
Question: I purchased an oleander a number of years ago. It was supposed to be bright pink, but when it bloomed, it had two different colors of flowers. It appears there are two plants in the pot. A nurseryman says he’s never seen one of that color. Is it a mutation? E.S., Texarkana.
Answer: There are several dozen varieties of oleanders, and I’m relatively sure you got a pot that had cuttings from two different varieties. Trace the flowers back down to the soil line. If all the bright pink flowers come off one stem, and if all the double pale pink flowers come from the other stem, it’s just a mixed planting and not a mutation.
Question: What’s going on with my live oak? Why so much split bark? I’m not aware of any possible cause. S.R., no city given.
Answer: It seems like I’m getting this question and photos just like yours every week through my magazine, newspaper columns and friends I see on the street. You are definitely NOT alone. This is the year of live oak bark splits. I’ve looked at several of the trees, and there seems to be no specific cause other than perhaps the hot, dry summer. The trees have all looked healthy. Your best bet, of course, would be to have a certified arborist look at the trees. Otherwise, maybe just sit tight until spring and see what pans out. Hopefully, some rains will develop and the trees will return to more normal growth next year.