Neil Sperry's Mailbag

DEAR NEIL: I have two weeping willows, one hybrid poplar and a river birch tree, and they’re all fairly close to one another. The willows and poplar are two years old, and I’ve had the birch for one year. Now, all of their leaves are turning brown. The problem started very quickly. Could it be too much water? Not enough?

Those are all very problematic trees. Any time you choose for fast growth, you’re inviting serious troubles. Willows are our shortest-lived trees (probably tied with purple-leafed plums). They’re highly susceptible to cottonwood borers. Poplars are cottonwood sisters, so they’re obviously susceptible, too. These are large insects that are almost impossible to prevent or control. River birch, where they’re adapted in deep East Texas, are satisfactory trees, but they, too, bring a lot of insect problems. The fact that four young trees developed problems at an early age and simultaneously, however, also suggests the possibility of a weedkiller or weed-and-feed fertilizer doing damage to them. Unfortunately, browned leaves aren’t much of a clue to get to the next level of answer. Take a closer look, then take samples to a nurseryman. It’s certainly not going to be due to too much water with that group of trees, and it probably isn’t too little water this early in the warm season.

DEAR NEIL: I live near a lake, and we always have fish parts. I’d like to know the best way to turn these into fertilizer, but I’m concerned about composting them due to rodents. Is it possible?

Probably so, although it’s a science of its own. Native Americans taught early settlers to bury the fish parts. It would seem that, if you could grind them as fine as possible, that the rodent issue wouldn’t be a major problem. Or, perhaps you could design some type of heavy wire covering to go over the compost bin until they had decayed sufficiently. Layer them in with several inches of loose organic matter such as dried tree leaves to confine the odors. In all honesty, while this is a great question, it’s certainly not my area of expertise.

DEAR NEIL: Most of my plums have worm holes. What can I do to stop them?

You need to follow the Texas A&M Homeowner Fruit and Nut Spray Schedule.

It’s normally found online at the TAMU Horticulture website, but it is undergoing revisions of product recommendations. However, there is nothing you can do at this point. These are plum curculios, and the sprays to prevent them begin while the plants are just starting to bud out. Follow the TAMU spray recommendations carefully. If you don’t, the larvae are almost inevitable.

DEAR NEIL: What is wrong with my red oleanders? This is their fifth year. They have flowered a lot, but the leaves are falling off. Can you help me?

Thank you, for the very clear photographs. They help immensely with identifying your problem. Look closely at the branches. The yellowed leaves are all older leaves (last year’s leaves). The new growth is doing fine.

While it’s normal for evergreen plants, including oleanders, to shed all their old leaves at some point, it’s unusual for them to be so dramatic about it. Let them run their course. Apply a high-nitrogen fertilizer, and water the plants well. Time will take care of your problem.

DEAR NEIL: Last year we planted a magnolia tree. It did fine for the year, but we noticed recently that the tree had discolored leaves on it. The leaves eventually dropped, and now the tree is beginning to look less green and the leaves are continuing to fall. Is this a lack of fertilizer, or is it some kind of fungus?

This is actually the same answer as for the oleanders. Magnolias drop their prior year’s leaves in April and May. At the same time the new leaves will be developing. The fact that this year’s growth is not as dark as you would expect is probably due to lack of nitrogen. Apply a good lawn food (no weedkiller included), and water the tree deeply.

DEAR NEIL: I have 150 feet of property, and I’d like to plant a screen that grows rapidly and covers thickly. It doesn’t have to have flowers. I was thinking about Thuja. How well will it do? How fast does it grow? Is there a better choice?

Arborvitaes of various types would be good, but rather enclosing visually.

They are dense, but not fast. There may be better options. You didn’t mention how tall you want the screen to grow. That would have helped give you a better answer. For 10- to 15-foot screens I would suggest Nellie R. Stevens or yaupon hollies. For 15- to 20-foot plants, Japanese ligustrum would be good, as would cherry laurels in acidic soils. Old-fashioned Chinese photinias would be outstanding in that same size if they were available in nurseries. Redtip photinias, however, are not a good option due to Entomosporium fungal leaf spot which is devastating that species nationally. The best of the tall screens would be eastern redcedar junipers, Little Gem or Teddy Bear magnolias and even live oaks. Spacing will vary with the type you choose. Let your nurseryman advise you.

DEAR NEIL: How can we keep a woodpecker and wrens off our hummingbird feeder? The poor hummers don’t have a chance. We do have a bird bath about 5 feet from the feeder.

This horticulturist will attempt to give an ornithological answer. Either move the birdbath or the hummingbird feeder. It sounds like congested air space. (That’s assuming the woodpeckers and wrens aren’t actually dining on the mix you’re putting into your feeder.)

DEAR NEIL: Squirrels are making a mess out of my pot plants. They are digging up newly planted pots, also older and more established plants. I’ve tried red pepper flakes sprinkled on top of the ground, also mothballs at different times. Neither has helped. Any suggestions?

You may be able to cut some small pieces of a roll-type mulch or chicken wire to fit over the soil surface until the plants can get rooted. Your main goal will be to change the pattern of their habits. You might also be able to place golf ball-sized rocks on top of the soil to discourage them.

For an extreme case, it might even be possible to rig up some type of motion detector to turn on a light or sound a loud noise anytime they came into its field of vision.

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.

Neil Sperry
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