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Monday - August 11, 2014

From: Terlingua, TX
Region: Select Region
Topic: Container Gardens, Watering, Drought Tolerant, Trees
Title: Leaves dropping from a potted Mesquite
Answered by: Guy Thompson

QUESTION:

I have a Prosopis pubescens (Screwbean Mesquite) that I purchased at a nursery in Alpine, TX just a few miles away from me. It was a in nursery style black plastic container. The mesquite is perhaps a couple of years old or younger. I transplanted it earlier this past Spring into a large clay pot. I have the pot sitting on a bed of pea gravel on a clay saucer so that it doesn't actually sit in water. I water it in frequently since it is a native to this area and it seemed to be doing very well. It had a lot of new growth and leafed out very well and bloomed after I purchased it. The water here contains a lot of mineral salts so every two weeks I sweeten the water with a Sea Tea that I purchased that is Kelp and Fish. The mesquite produced a few screwbean pods as well. Some of the leaves on the tips of the branches are turning yellow, not everyone of them but enough to cause concern. That was a few weeks ago and now some of the green leaves are dropping. Not just A leaf but the entire leaf stem that contains the five to six individual leaves. Is it the clay pot do you think and that the roots are getting too hot or something else. I have it in a clay pot so I could move it to my property if I decide to place a home on it. At this time I rent, so my small garden is a container garden. I would appreciate any assistance with this.

ANSWER:

I think I know why your Prosopis pubescens (Screwbean mesquite) is dropping leaves. As described in this web site, mesquites have huge root systems, both laterally and through their tap root. Because of this, the plant can maintain a steady supply of moisture, even in moderate drought. In severe drought leaves begin to drop, as mentioned in the web site. Your mesquite, growing as it presently is in a relatively small pot, may experience a sudden shortage of water much more quickly than it would in nature because of its greatly constricted root system. So your infrequent watering may not be enough. You may need to water more frequently or use a drip system to provide a constant moisture level.