Q. I came across your gardening articles in the OC Register. I do have a question about my loquat tree, and I was wondering if you would be willing to help me identify the problem. I have attached several pictures to help. Anyway, I’m not sure what is growing at the base of the tree but each time I remove it, it seems to grow back. It seems to be soft like but intact when removing it. I’m in Irvine and the loquat tree has been in the yard since around 2010. There are some other issues with the tree such as the bark splitting. I know at some point that the tree might need to be removed but it is hard to imagine that day when there nothing in that spot and providing some shade to the nearby plants.
Things are not looking good for your loquat, I’m sorry to say.
Bark splitting is often caused by sun damage. Intense sun exposure (usually on the south- or west-facing side of the trunk) damages the bark and can cause the cambium to expand and split the wood. This weakens the tree and allows insects and/or disease to enter and wreak havoc. In this case, armillaria (a fungus) has infected your tree. The soft material that you are removing is the fruiting body of the fungus. Unfortunately, that’s only a small portion of the fungus – the rest of it has spread into the tree and can’t be removed. Your tree should be removed.
There are several steps you can take to prevent this from happening to the next tree you plant. Paint the exposed trunk with diluted white latex paint (diluted 50% with water). Allow the lower branches to grow until the upper branches can provide adequate shade for the trunk. The trunk doesn’t have to be completely shaded, but it should get at least 50% shade to protect it from sunburn. Loquats have a tendency to grow outwards and get kind of sprawly, so let it do its thing so the trunk can stay protected.
Q. Our small palm seems to get enough water and we fed it a few weeks ago, multipurpose plant and lawn food, Greenall. The orange and yellow leaves look like it’s not healthy. It’s about 2 years old and was professionally planted.
Palm trees will normally have some yellow fronds, usually the lower-growing older ones that should be removed. When the entire tree is yellow, a nutrient deficiency is often the cause. In pygmy date palms, this is most likely potassium.
If possible, you may want to test your soil for the presence of micro- and macro-nutrients. It looks like your palm is planted in decomposed granite, which is highly alkaline (high pH) and nutrient deficient. The problem with alkaline soil is that it tends to bind nutrients, especially iron. This can result in the overall yellowing that you’re seeing.
Regular application of a slow-release fertilizer, preferably one formulated especially for palms, can correct this. Depending on the soil test results, you may need to supplement this with a fertilizer that provides the needed nutrients.
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