GARDENER'S MAILBAG: What happened to my Mexican plum?

By Neil Sperry
Special to the Herald Democrat

Dear Neil: This happened to my Mexican plum last summer. What caused it, and what can I do to prevent it this year?

Mexican Plum Bacterial Leaf Spot

At first glance I thought this had been caused by caterpillars, but then I decided to Google “Texas A&M plant pathology bacterial leaf spot Mexican plum.” Sure enough, as with domesticated varieties, this disease causes leaf spots that later turn brown and drop out. Their report does say that chemical control is not highly effective on fruit-producing varieties, so I can’t get you much farther down the road, but at least you have an ID and a resource.

Dear Neil: I have a vine that seems to crop up everywhere. (See photo of it in a stone path.) How can I eliminate it?

The photo is blurry, but it appears to be some type of ivy (genus Hedera). I’d suggest that you try a broadleafed weedkiller (containing 2,4-D) applied directly and only to the ivy.

Dear Neil: I had a large area of my lawn that I had covered with lantana. We were trying to cut down on the amount of grass we were maintaining. Now the lantana looks like it’s not coming back, and the city is citing me. What should I tell the inspector?

Sago Palm Resprouting

You’re probably going to have to replace the lantana if it hasn’t resprouted by now. Granted, shrubs and perennials were slow to leaf out because of continued cool weather this spring, but enough time has passed. Turf is usually the lowest maintenance living cover for most landscape areas, so maybe you could consider going back to a compromise of some turf and some lantana or other flowering perennials.

Dear Neil: We have a large post oak in the Hill Country that we have lost to Hypoxylon canker. Can we use the chips from having the stump ground in our compost back at home? Is there any danger of spreading the disease in that way?

I spent some time on university plant pathology websites trying to find a good answer for you. The Texas A&M Forest Service has a fact sheet on Hypoxylon canker that tells us that the spores are rather omnipresent in wooded areas and that it’s almost impossible to keep trees from being exposed to them. It’s when trees are weakened, for example, by drought, that the disease takes over. It sounds like the chips should be fine in your compost. You’re welcome to do some more searching online, however. I only spent 30 minutes on it. That doesn’t make me an expert.

Dear Neil: We didn’t get our cast iron plants protected like you did, so ours turned brown. Should they be cut back just above ground line?

They should be cut back, but they have started to grow by now, so you can’t cut them that low or you’ll be cutting new leaves. Trim just above the new growth.

Dear Neil: We have Turk’s cap planted beneath live oaks. We’d like to put mulch down around them for the good looks it brings. However, there are a couple of inches of live oak leaves on the ground there now. Must they be removed first. I know they’re serving the same purpose, but we both prefer the looks of the mulch.

I would remove live oak leaves. They don’t break down very rapidly. They will pack down and form an almost impenetrable layer of organic matter – like a thatch roof. Wait for a warm, dry day and just blow them out. It should be fairly easy.

Dear Neil: My sago palm is growing new leaves. It survived the cold and snow. Don’t give up on them!

The sago and palm experts told us clear back in February that it might be May or even June (on the taller types) before we would know if they had survived. So glad yours has! I’ll bet the layer of snow was just the insulation it needed. That’s been the case for many types of low-growing plants.

Dear Neil: I have a Brown Turkey fig that survived the cold and is growing well. However, it has no figs this year. Do you think they will sprout later, or will they come back next year? I’ve always gotten a good crop.

It will be fine, but 2021 will probably not see you harvesting figs from it. You’re just lucky it made it through the cold. Many people would consider that a major victory, as they’re having to start over with new fig plants.

Dear Neil: I’ve attached a photo of a 3-shrub “hedge” of loropetalum in front of our house. It’s done well for 12 years until last fall. It started to show signs of declining, and then February seemed to kill it. Now it’s trying to come back with small buds. Should I wait on it?

Loropetalum Row In Foreground

If you had told me only about the winter damage, I’d be tempted to give it that second chance, but since it seemed to be going downhill prior to winter, it may have run out of steam, either because the soil wasn’t to its liking or because it had been pruned repeatedly to the same height and may have simply worn out. It’s probably time to start over. If you were happy with it in the first place you could rework the bed and replant with more loropetalums, or you could change over to dwarf hollies, dwarf abelias, boxwoods or some other low-growing plant.

Dear Neil: My Shumard red oak is only leafing out on one side. The other side has no leaves at all. Is that because of the February cold? Will it all catch up? Is there anything I need to do or anyone I need to call?

To your first question, yes, that’s due to the cold, and it’s a phenomenon we’re seeing all across Texas. Red oaks have been completely erratic. Many have leafed out entirely normally. Some still have absolutely no leaves. Many have leaves on portions of the tree like you’re describing. The state’s finest arborists and foresters tell me, however, that we all need to sit back and relax for a few weeks. We need to let Nature take its course – that most of this will even out and most of the trees will be back to normal by the time we get into summer. There is nothing we can or should do to speed it along or to guarantee their success. It just is what it is. Above all, however, do not have them pruned now. For one thing, this is the prime season for the spread of the oak wilt fungus, so you really don’t want to expose their internal wood to that fungus by pruning before mid-July. Plus, most of the pruning will end up not being necessary in the first place.

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.