GARDENER'S MAILBAG: Why is my live oak taking so long to leaf?

By Neil Sperry
Special to the Herald Democrat

Dear Neil: We have a large Shumard red oak that seems to be competing to be the last tree to leaf out on our block. Some branches have many leaves, while others are sparse. Is this a result of the cold or could there be other things going on?

There’s always a chance of other things being involved, but I’ve had scores of questions about this over the past month. In consulting some of the state’s most respected arborists and foresters I keep hearing the caution of “patience.” They’re saying our trees may not be functioning completely normally until we get into summer. If it’s anything like the latent drought damage we experienced after 2011 (effects that were still showing up several years later), it may go on longer than that.

Dear Neil: The bark of several of my mature azalea plants is peeling at ground level. If I prune them all the way back to the soil will the roots produce new stems?

Azalea Trunk Bark Splitting

They ought to be doing that on their own by now if they’re going to do so. My guess would be that you’ll be far better off just replanting with fresh, vigorous stock. (Before you discard these plants, double check those white specks to be sure they’re not soft-bodied azalea bark scale insects. I can’t see them well enough to tell.)

Dear Neil: I recently moved into a home that has an aerobic septic system. Can I use it to irrigate my zoysia lawn, or will mineral salts from our house’s water softener ruin my plants? Is there anything I can do to counteract it? It seems like the perfect solution to our hot, dry summers.

You have asked a very good question. To some degree you don’t have a choice. You are probably required to have the aerobic system, and that means that you will also be required to have a spray field for it. So, some of your plantings will, by necessity, be getting sprayed. Luckily, you hinted that it will essentially be only zoysia turf. However, since it will be coming partially from toilets, bathtubs and the sink disposal, you must be cautious not to overspray edible crops with it. This article from Prof. Kim Coder of the University of Georgia gives a really good overall summary: https://ugaurbanag.com/using-gray-water-in-your-landscape-and-garden/. It’s also very important that you utilize regular soil testing to monitor soluble salt accumulations.

Dear Neil: I have pittosporums, pride of Barbados, broom, mother-in-law’s tongue, Aloe vera, airplane plant and several other plants that are still showing no signs of sprouting back out again. How much longer should I wait?

You’ve given all those plants on your list more than ample time. Most of those (less so the pittosporum) are very sensitive to freezing temperatures, and what they experienced was more than enough to kill them. It’s time to move on.

Dear Neil: We have lived in two homes that had loquat trees (now frozen). Both had Asian jasmine in beds beneath the loquats and extending out beyond their loquats’ branches. Beneath the trees the jasmine was weak and thin, but out in the open it thrived. Is there something in loquat leaves that would inhibit growth of the jasmine?

No. Nothing that would drip into the soil, and the loquat leaves wouldn’t be decaying in place – that takes way too long. The only possible cause I can think of would be competition for sunlight and water, both critical to the Asian jasmine’s success. Loquats cast heavy shade, and they use a great deal of water.

Dear Neil: My live oak has tons of these little sprouts all around it. Pulling them would be very tedious. I’m reluctant to put a weedkiller on them until I have professional advice. What would you suggest?

Live Oak Sprouts Or Seedlings

These all look like young seedlings of approximately the same age. It’s possible they all sprouted from acorns this spring. Typically, when I get this question about a live oak, it’s actually root sprouts that are tethered to the mother tree, and in those cases we can’t use a weedkiller because it would be taken back through the tree’s root system to the maternal tree. So, to see if you might be able to do that in this case, soak on area thoroughly, and then, a few hours later, carefully dig a few of these with a small trowel. If they come up easily, and especially if you can trace all of their roots back to one acorn per sprout, they would obviously be seedlings. In that case you could apply a broadleafed weedkiller containing 2,4-D. If they are sprouts from larger roots, all you can do is sever or mow them. That’s a genetic blemish of about 15 percent of the live oak trees that I see.

Dear Neil: I saw your comment about training Nellie R. Stevens hollies to be more tree-like instead of using them as shrubs. Is that something I could do? How do they look?

Nellie R Stevens Tree Form

I can show you how my own plant looks. The only requirement is that you have a plant with a fairly straight central trunk (or perhaps three trunks) that will look good as you start to remove the side branches. Do it one branch at a time, even if it takes a period of a year or more. It’s definitely something that anyone can accomplish.

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.