Hiring for Oak Wilt in San Antonio: What to Ask

Oak wilt is a disease that rewards competence and punishes guesswork, and the quality of the work available in San Antonio varies more than in almost any other kind of tree job. The good news is that a handful of questions sorts it out quickly, because the right answers are specific and the wrong ones are vague.

Before anyone comes out

Do fifteen minutes of your own work first. It makes every conversation afterward better.

• Photograph a few leaves from an affected branch, held up to the light, showing whether discoloration follows the veins.
• Photograph the whole tree from far enough back to show how much canopy is affected.
• Identify whether it is a live oak or a red oak - see live oak vs red oak symptoms.
• Walk the block and note any other oaks that look off, and roughly where they are.

That last one is the single most useful piece of information and almost nobody arrives with it.

The nine questions

1. Is this a live oak or a red oak, and what does that change here?

A straight answer distinguishes the two clearly - live oaks decline slowly and may be treatment candidates, red oaks die fast and are removals. Someone who treats them interchangeably is not going to manage this well.

2. Where do you think the infection center is, and how far does it extend?

This is the question that separates an assessment from a quote. Oak wilt is a property-level and often a block-level problem. Anyone who looks at one tree, quotes work on that tree, and never mentions the ones around it is selling a service, not solving the problem.

3. Are there root grafts here, and should we be trenching?

If the answer is no, they should be able to say why - one oak on the lot, nothing within root distance, no coherent front. If the answer is yes, where and how deep.

4. If you are recommending injection, why is this tree a good candidate?

Good answers reference canopy condition and species. A good candidate is a live oak with most of its canopy intact. Recommending injection for a red oak, or for a live oak that has already lost half its crown, is a bad sign.

5. Are you licensed for propiconazole application in Texas?

It is a restricted-use application. Ask to see the license. Ask whether the injection is macro-infusion at the root flare, which is the accepted method.

6. What is the retreatment interval and what does it cost?

Injection is not one-and-done. If nobody mentions that the treatment repeats every one to two years indefinitely, you are being quoted a fraction of the real cost.

7. When will you do this work, and will you paint the cuts?

The right answer is that oak cutting is avoided February through June where possible, and that every cut is painted immediately regardless of season. See when to prune oaks. A crew that says painting is optional or outdated is applying general arboriculture without the local exception.

8. What happens to the wood?

Fresh, bark-on red oak from a diseased tree should not be left on site or moved off it casually. Hauled and disposed, or chipped. See oak wilt and firewood.

9. Can I see your certificate of insurance, sent directly from your carrier?

Liability and workers compensation. This is not paperwork theater - large oak removals near structures are the job where an uninsured crew becomes your financial problem.

Answers that should end the conversation

• "We can cure the oak wilt." There is no cure. There is management.
• "You should inject all your oaks." Blanket injection of every tree on a property is a sales program, not a treatment plan.
• "We can treat that red oak." Almost never appropriate.
• "Painting cuts is outdated." True in general arboriculture, wrong in Central Texas.
• "We do not need to look at the neighbors' trees." Root grafts cross property lines. A plan that stops at your fence usually does not work.
• "Sign today for this price." Oak wilt is a chronic condition. Nothing about it requires a same-day decision, with the single exception of removing a dead red oak that may form spore mats.

Credentials worth asking about

An ISA Certified Arborist credential is a reasonable baseline for the assessment side. Texas Oak Wilt Qualified is a more specific credential and is directly on point. Neither is a guarantee, and plenty of excellent Central Texas crews have been doing this correctly for twenty years, but combined with good answers to the questions above they raise confidence considerably.

The shape of a good plan

A competent oak wilt plan on a badly affected San Antonio property tends to look like this, in this order:

1. Remove dead and dying red oaks immediately, and dispose of the wood.
2. Map the infection center by walking the property and the adjacent ones.
3. Trench well outside the front, continuously, at four feet or deeper.
4. Inject the specific high-value live oaks worth injecting, and only those.
5. Leave the oaks alone from February through June, and paint any unavoidable wound within minutes.

If the quote in front of you is item 4 alone, you are looking at the easy half of the job.