I think you want the "trees" forum, but I had the same problem 5 years ago with the center top branch of my young tree-about 10 footer. I cut it out and it filled in fine.

Sounds like maybe too much synthetic fertilizer during the summer. It happens to mine. I avoid synthetic fast acting fertilizer during hot and dry weather.

When the top of the tree struggles it simply indicates that the tree is struggling to get water and nutrients to the top. This can be the result of several different problems, such as cankers, wounds, environmental stresses, or pest activity. In your case, you mentioned the heat wave and that the tree has been in place for 3 years. Unless you can find evidence of damage to the trunk or surrounding roots, I think it is safe to assume that the roots were struggling during the heat wave. I recommend using a soaker hose during stressful periods and for the next 6 weeks, once every 10 days to thoroughly soak the root system down. It is important not to over do the frequency, because you want the root system to develop deep roots and not flourish at the surface (so keep at least one week between waterings). Also, considering that the tree is in a landscape rather than a natural wooded area, supplemental feeding will go a long way in promoting root development and growth. If you have an arborist or tree service that does root zone feeding in the area, you might give them a call for a fertilization. Make sure that they know what they are doing, as many services (even those with brand names) are bad to come out and scatter lawn fertilizer out and call it a "root zone feeding." Tree fertilizers are usually a mix of Water Soluble Nitrogen, Phosphates, Potassium and Bacteria/ Fungi Cultures for continued nutrient fixation. I used Bacillus Cultures for my customers, which colonize around the roots and improve root performance. You want to fertilize before new growth or shoot elongation begins so do this soon. After shoot elongation begins, macro nutrients should not be used until late Fall after the first heavy frost.

As for pruning, I don't recommend this yet. Let the tree fully transition into Spring before determining if the branches are dead. I'm in Atlanta and not all of the maples have completed their transition yet, particularly those on the north side of homes, where the soil temperatures are slightly lower this time of year. So I would expect that if you fertilize properly and water, the top will recover. If you find that several weeks from now, some branches are clearly dead while others have fully mature leaves, then you would need to prune the dead branches out to allow the tree to recover. I will be covering that subject in an upcoming video.

If you're interested in what a tree fertilization looks like you're welcome to view the link below. Just click "root zone fertilization" on the right side of the page.

Here is a link that might be useful: tree shrub

thanks.
actually all of the maples got hit w/ some sort of boring insect. but it was the autum blaze that didn't handle the heat wave.

i thought after 2+ years they could handle heat, lack of rain on their own, guess i was wrong.

i see no buds on the tops, and i got up on ladder and scraped some bark, no green. i believe that means dead.

how many years should i keep an eye on them in heat conditions?

i watched video, guess the closest thing i could DIY are spikes. we have tan clay soil here, not red...but its clay for sure.

The spikes are actually effective, but remember that they need to get down deeper for trees.

The main concern with your reply is the boring insect. Beetle activity can lead to numerous problems. However, in many cases, boring insects are assumed to be the cause of holes found in the bark. The most common cause is actually wood peckers and sap suckers. These varieties of birds will produce rows of holes in the tree bark. By wounding the tree, they lay a trap for insects. Once the sap begins to run and attract insect activity the bird revisits the holes to feed.

I hope that it's bird activity rather than a boring beetle. The beetle activity is much more serious.

As for the branches, it really depends on how far down the dead portion is. Pruning off dead areas is a good idea, but I still recommend waiting until it fully transitions. This has to do with the tree's cambium layer being able to seal over and cover the pruned area.

I will post a video on Facebook in the next week with pruning tips and instructions if you're interested.

Here is a link that might be useful: Facebook link

It was definitely a larva of something. Behind the dying bark I pulled away there was a cavity that the larva left. Went in a hole then chewed out a section under it. In my birches I actually found one in the act, I saw a pile of fresh frass looked up the trunk it has the same pattern, a single entry hole with a bunch of the sap wood eaten hidden by bark. The maples had the exact same type of damage. By the time I saw it on maples it has been a while, the sapwood/cambian had healed behind the bark.

I have photos of it, damage and worm, I could post them. Not sure how on this site yet.

I will wait to trim them out.

I hate to hear that. There are a number of places, including the holes from birds I mentioned earlier, that are bad about allowing for insect penetration. Unfortunately, the insecticides that are most effective at killing borers have been removed from the market.

My recommendation is to find a bifenthrin product, such as Talstar P. Mix this in a handcan and treat any damaged areas every six weeks during the growing season with 20 oz per gallon. Main points of emphasis are 1) open unsealed wounds from pruning 2) the bark at the crotch between a branch and the trunk 3) holes produced by birds 4) trimmer or mower injury 5) areas with dead or damaged wood, such as dead limbs (before and after pruning).

Treating these areas at that rate and frequency will leave a residual that will help protect the tree from further infestation.

have a picture of it now
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