Crabtree Help

Asked June 6, 2016, 11:51 AM EDT

Hello - I am hoping for your help. We planted this crabtree in our front yard 12 years ago, and it has thrived, up until this year. In April, we noticed as soon as it started to bud that something was wrong. Barely any flowers. Many branches are nearly bare and leaves remain very small on all but a few branches. Some leaves are starting to yellow. However of the other green leaves, I don't see signs of the leaves actually being damaged. The leaves are just small and much fewer in number. I looked for signed of root rot, and saw some spots of whitish bark (as per the photo). But I'm not sure if that is significant or not. We've never sprayed or pruned the tree. One other note: I'm not sure if this would make a difference, but last summer, we pulled out the perennial garden that had always been around the tree, and instead placed week barrier over the soil and then topped with pea rock. I'm not sure if this would impact anything, but it was a change that corresponds with the tree problem. Please let us know if there is anything we can do to fix our tree. Any help or resources would be most welcomed. See attached photos as well. Thank you so much!! Debra Pexa Heidelberg, MN

Le Sueur County Minnesota crab apple trees

4 Responses

Hi Debra,
I'm not sure what is going on with your tree, but it is possible that the rock mulch is gathering too much heat from the sunlight and harming the surface roots. Roots grow in the top-most 2-18 inches of soil and extend out beyond the canopy area.

In removing the perennial garden, and preparing the soil for the landscape cloth and rock it is likely that many of these important roots were severed or injured. The tree may simply be responding to that injury. Rock is not a good ground cover for many reasons, but this heat-gathering action is one of the more significant ones. the tree may recover if it is kept well watered. It looks as if you fertilize your lawn, so you shouldn't have to fertilize the tree, too.

It appears that there is a lot of suckering going on at the base of the tree (Unless these are plants that you have planted there - it's hard to see tell from the photo). These suckers should be removed as they are taking nutrients and water from the tree. They are probably growing out of the root stock that the tree was grafted onto.

Then - it is possible that the tree has a disease or insect issue. Here is a diagnostic website. See if you can find any of the symptoms that are mentioned:
http://www.extension.umn.edu/garden/diagnose/plant/deciduous/crabapple/leavesbrown.html

I hope this is helpful. Please contact AaE again if you have further questions.

Thank you so much. That is very helpful. We haven't fertilized the lawn, so maybe we can fertilize the tree to give it a boost. We'll start watering too. I'll check the site you list and see if we can further diagnose.

We are really grateful for this resource!!

Debra

I'd recommend using a lower dose of fertilizer until you know for sure what is going on. If there is root damage the tree will not be able to handle the fertilizer well, and it could add to the damage.

Thank you!