Take care of your trees with these timely tips for the winter
There are several important questions pertaining to trees that come up this time of the year. Let’s spend a couple of minutes addressing them now.
“Is there any way to stop our oaks from producing so many acorns? There are so many of them this year.”
Acorns are just the trees’ means of reproducing their species. There are no sprays that will render the trees “fruitless.” You could use your blower to gather them into piles along the edge of your property where you could pick them up with a shovel, or you might be able to rake them up with a leaf rake. Low-powered lawn vacuums can be used to pick up small sticks as well as the acorns. The good news is that oaks, like pecans are “alternate-bearers.” That means that they’ll have a big crop one year (like this year) and then very light or no crops the next year.
“Our tree has two roots that look like they might threaten our foundation unless we intervene. They’re about 2 inches in diameter and the tree is 15 feet from the house. What can we do and when should we do it?”
It sounds like you might want to remove them. As a general rule, late fall or early winter is the best time to do so. That allows the tree several months to respond to the removal by growing deeper roots prior to the next summer’s hot, dry weather. You still could do that now, but don’t put it off much longer. Talk to a certified arborist about installing a root barrier to prevent roots from growing toward the foundation as well.
“I need to prune my live oak to get it off my roof. When should I do it so I won’t expose it to oak wilt?”
This recommendation has evolved over the years. Initially we were told that you always would want to prune during the cold winter months while the oak wilt fungal mats were completely dormant and while insects that transmit the fungus were inactive. Then arborists, foresters and pathologists expanded that answer to include late summer and fall, saying that the mats are inactive at those times, too. So now we are told that we can prune anytime from mid-July through mid-February. The season we must avoid if at all possible is mid-February through mid-July. All cut surfaces made to oaks at any time must be sealed with pruning paint immediately after the cuts are made
“We have a bunch of pecans still hanging in our trees. Why haven’t they fallen like the others?”
They’re probably no good, with kernels that never filled out due to damage done in August by hickory shuckworms in the outer husks. They’ll fall sometime this winter or early spring, but the husks will remain attached to the pecans. If you’re trying to produce the best possible crop of pecans you’ll need to spray to protect them in early August and again three weeks later using Malathion or other labeled insecticide. That same spray will protect the pecans against pecan weevils.
“When is the best time to transplant a tree in our landscape? It’s in the way of where we want to build a new pool.”
Transplanting of woody plants, including trees and shrubs, must be done during the winter while they are dormant. Pruning sets plants’ growth back, so it’s critical that we give them time to recover. You also want to trim the top growth back proportionate to the amount of roots you have to remove. Set the tree at the same depth at which it was growing before and apply a high-phosphorus root stimulator monthly for the first year.
“It looks like we’ve had a good bit of erosion beneath our trees. The ground is bare and we can see the roots. Can we add soil to cover the roots? When should we do it?”
I’m going to take the answer in a different direction than what most might expect. Most times this ends up being something entirely different. Shade causes the grass to die out, and then as the major surface roots grow larger they swell up and out of the soil. I see it all the time. It’s usually not erosion at all, in which case adding soil over the roots would drive much-needed oxygen out of the root zone – a very bad thing.
In those less common instances where erosion actually has occurred you can replace what has washed away. It’s probably best to replace the eroded soil with the same type of topsoil, but hopefully you won’t be covering more than 15 or 20 percent of the root area of the tree and hopefully with no more than an inch or so in a given year.
In either case you’ll want to find a good ground cover for the area. My own choice in both of these situations in our landscape has been mondograss (“monkeygrass”). It holds the soil tenaciously against erosion, and it also thrives in shade where turf just can’t survive.
“There are rows of holes in the trunk of our live oak. Are they anything we need to worry about? The tree looks healthy otherwise.”
Woodpeckers and sapsuckers cause those. They perch on the trunk and peck their ways around almost like a machine gun has strafed the tree. They don’t suggest the presence of any particular insect, nor do they cause a problem on their own unless they riddle the same spot on the trunk repeatedly. You’ll see their effects on pecans as well. I’ve had them harm a couple of hollies in our landscape, and for that I’ve sealed the open wounds with pruning paint and applied a product called Tree Tanglefoot (not always easy to find) to discourage their further work.
You can hear Neil Sperry on KLIF 570AM on Saturday afternoons 1-3 pm and on WBAP 820AM Sunday mornings 8-10 am. Join him at www.neilsperry.com and follow him on Facebook.