Organic Answers Column – November 1, 2023 – Hybrid maples

Hybrid Maples

Since they are still being sold and planted out there, its time for another warning about these problematic maples. I learned the hard way that hybrid red maples are poor tree selections and don’t live long. Their thin bark commonly leads to sunscald but there are several other issues. See the list below.

Back in the 80’s I designed several variations of these cross-breeds into a commercial landscape project in Plano, Texas – Collin County Community College. There were all dead within 10 years. Some of them didn’t last 5.

Fall color: why the hybrid maples are being sold so much.

What to do instead? The native Texas maples are far superior, especially Bigtooth maple. Chalk and Caddo maples are also good but slower growing. Others worth considering include trident maple and most any of the Japanese maple choices. See the link to the page covering the selections I have at home. Shantung maple is in the “maybe” category. Several of them in north Texas are not holding up well, including one in my neighbor’s landscape.

The brilliant red foliage of Autumn Blaze maple (Acer freemanii ‘Jeffersred’) makes it a pretty tree at first, especially in the fall – but that’s all the good news. This and the other hybrids are crosses of red maple (Acer rubrum) and silver maple (Acer saccharinum). That’s the problem. Easy propagation and impressive fall color but bad health and short life.

Chlorosis

Autumn Blaze, October Glory and other hybrid maples often suffer from chlorosis, or iron (and other trace minerals) deficiency. The first sign will be yellow between the leaf veins.

Anthracnose

Anthracnose is a fungal disease that shows up as deformed leaves with discolored or dead blotches. It causes tan or brown spots on the leaves and it can lead to leaf drop.

Verticillium Wilt

This fungus blocks water movement in the tree by congesting its water-conducting tissue. Early symptoms include off-color, limp leaves that quickly turn dry and brittle and drop off. As the disease progresses, the soft sapwood beneath the bark turns dark green to black. The fungus is most active in cool weather, which means symptoms most likely will first appear in late spring.

Healthy hybrid maples on Lover’s Lane, Dallas, 2020 (left) and Dying hybrid maples in 2021.

Tar Spots

Rhytisma fungi causes tar spots that are nonlethal but unsightly. The spots start off in the spring on top of the leaves as small yellow areas. Heavy infections can cause early leaf drop.

Sun Scald

The hybrid maples are highly susceptible to trunk damage from the sun. It’s due to the thin bark these trees have and the fact that they are basically weak trees. If you have these trees and trunks are damaged, apply a latex paint mixed 50-50 with water. The tree will grow the white wash away and the trunks will re-acclimate. Using white paint is ok but choosing a paint color that matches the bark would be better.

Hybrid maples continued demise in 2022 (left) and Cut down and gone in 2023. Nothing left but some deformed crapemyrtles. Moral: don’t plant hybrid maples.

Freeze Damage

Along with all the other problems, the hybrid maples can be further weakened or killed by cold weather.

Visit the Japanese maple page here.