Xtremehorticulture

Xtremehorticulture of the Desert

Bottle Tree Losing Leaves

Leave a Comment / brachychiton populneus, death, dying, irrigation problem, limb dieback, overwatering, root rot /

Q. I have bottle trees planted next to the house and for some reason the one in the middle is losing leaves on the bottom branches. The trees are getting watered two times each week for 40 minutes. I cleared out the rock mulch and replaced it with cedar mulch around the base of the tree. I lost a bottle tree last year so I’m trying to figure out why. A. Bottle trees represent about 15 or 20 different types. All of them have a swollen trunk which, some people speculate, they use for storing some water during dry periods. We typically use only one type of bottle tree in the valley.             The cedar mulch won’t add any nutrients to the soil but it will slow evaporation of water from the soil surface. Bend side branches without leaves to see if they are dead. If they are still flexible and don’t snap, they may come back when it cools.             Remove any branches that are growing toward the house. Planting those trees in that location was not the best idea.             I remember these trees being brought into the valley as early as the late 1980s during our first push on desert landscaping. They were brought in by landscape contractors and architects because they were being used primarily in Southern California.             The first problem I remember was irrigation. People did not know that these trees required watering less often. They were watering them much like any other landscape plant. These trees are very susceptible to over irrigating.             Although not a desert tree like the Acacia, it does handle arid climates and infrequent waterings. These waterings, when they do occur, should flood the entire root system about 2 to 3 times a month during the summer. The next irrigation should not occur until the soil is dry or you run the chance of getting root rot and the tree may suddenly die during the summer heat.             The next problem was how they were being used. The tree needs to be in full sun. They should not be planted against hot South or West facing wall. Very young, green trunks of this tree can get severe sunscald in these locations followed by limb and branch death.

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Shoestring Acacia Losing Lots of Leaves

9 Comments / acacia stenophylla, irrigation problem, phyllodes /

Freeze damage to shoestring acacia Q. I had three shoestring acacia trees planted 5 years ago and right now they are losing a tremendous amount of leaves. They are on high flow emitters that are adjustable and putting out a large amount of water. They get watered every other day for 15 minutes. The trees are approximately 20 feet tall.             Is there any reason why they would lose so many leaves?  My understanding with these trees is they produce very little litter but that is not the case. I would appreciate any help you could give me on this. Also there are 4 emitters for each tree about eight to ten feet from the trunk. A. Shoestring Acacias (Acacia stenophylla) has a long record of success in desert regions of the west.  This good history of success is often the result its adaptability and letting the soil dry between waterings.  Flowers of shoestring acacia             Your comment that the ‘leaves’ are falling (Oddity fact: The long thin ‘leaves’ are in fact phyllodes and not true leaves but do the photosynthesis) leads me to think the very frequent watering has set up conditions not conducive for a maturing tree.             After 5 years in the ground I would think your watering cycle could be as much an issue as anything.  Unless you live on some of the very sandy, stable dune soils of Palm Springs or in southern California/southwestern Arizona (Yuma mesa area) trees in the ground for 5 years would be better watered much less frequently with a larger volume at each watering.  This would also include having the source of the water being moved out away from the trunk targeting the water out closer to the drip line of the tree.              Whether there might be a disease involved and complicating the situation is nearly secondary.  The watering regime you described could easily have set up the conditions for the fungus to get started and any treatment would include a change in watering schedule to allow drying between waterings.             Please feel free to respond if you have any questions or other things that might have ‘hit’ the tree. Things like: root damage from digging, severe wind that may have damaged the trunk, certain herbicide (weed killer) usage, pool back flushing, inadvertent chemicals spilled in the area, compaction from parking vehicles in the tree’s shade, etc.              I would be interested if you live in a marginal cold area.  This tree begins to suffer if the temperatures drop to the high ‘teens. Terry Mikel

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