What’s wrong with my mountain laurel?

Thanks to Scott Stoker for this great question and picture about his troubled native mountain laurel.

Scott writes that he transplanted it almost two years ago, but it’s never looked very strong and the leaves have always been more yellow than green, so he assumed that it was suffering from transplant shock; a common malady in Texas mountain laurels.

Scott says that the tree gets full sun most of the day, has a thick layer of mulch around it, and is planted in an area with “good organic soil.” He never fertilized until recently, and then only with a layer of chicken manure on top of the soil around the tree.

He goes on to describe his cultural practices over the last two years, which are directly in line with all of the information he’s read about how to grow a mountain laurel.

Well, this is indeed a complex situation, with several issues most likely at play, so I’ll do my best, Scott, to see if I can help you get your tree headed back in the right direction. Your use of the word “transplant” may be key, since Texas mountain laurels do not take kindly to being moved once they’re in the ground. If that’s the case, there’s your answer in a nutshell.

But I’ll assume that you actually planted the tree in this spot two years ago.  If the tree has never been quite healthy, it most likely was struggling before you ever brought it home. It’s pretty tall and a little lanky, so just extrapolating backwards, I would take a guess that your tree was in the same container at the nursery for longer than it should have been, which would stunt the roots and inhibit the trees growth. Any tree that, from the very start, doesn’t grow and never greens up is having root-related issues, whether they be from the lack of sufficient water and nutrients, or whether you’re doing everything right and there’s plenty of both, but it just can’t take them up. If the roots were overly damaged when you got the tree, it may not have the ability to recover. And honestly, I think that’s most of what’s going on here, but let’s make a few changes around the tree before you give up hope.

First, I would suggest removing the nearby plants from around the tree, so that you can control the environment better and it will have plenty of space to grow without competition. Also, it sounds as if the soil around your tree may be a little too rich with organic matter for a mountain laurel, so pull the mulch back away from the trunk and leave only a thin layer on top of the soil.

Next, apply a small dose of the fertilizer of your choosing, but with a relatively high amount of nitrogen, and no phosphorus or potassium. Also try some chelated iron fertilizer. If the yellowing of the leaves is related to nutrient deficiency one of those two should help it green up at least a bit. As I said, the roots were most likely stunted when you bought the tree, so they haven’t spread out much. Think back to how large the container was, and apply fertilizer in a circle around the trunk at and just beyond that distance. I would guess that’s probably in the neighborhood of 6 to 12 inches from the trunk.

Mountain laurels do tend to grow rather slowly, but watch for small changes, and please keep us updated on your tree’s progress!