Q. I was cleaning up the leaves from my Fan-Tex Ash
tree and noticed that there was sap leaking from 4 different limbs of the tree.
Attached are some pictures. The tree is about 18 years old.
Although the first picture shows a small number of leaves remaining, the
tree has always has had a nice canopy of leaves including this past year.
The tree is in rock much, but it receives nutrients (24-8-16) from an
in-line liquid fertilization system.
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| Readers Fan Tex ash tree |
caused by stress (not enough water) or some type of borer. The tree
receives about 30 gallons of water each time it is watered. In the winter
it is watered once a week, spring and fall twice a week, and in the summer 3
times a week. Is it common for this tree to have borers or is this
problem likely caused by insufficient water?
A. The amount of water it is receiving sounds about right or
possibly a little bit on the light side. It is definitely not being over
watered. Your frequency of application also sounds about right seasonally. If
this tree is surrounded by rock mulch then the amount of water applied may not
be enough.
Look at New Growth
year. At eighteen years of age the tree is in youthful maturity. The tree
should be growing at least 8 to 12 inches minimum every year of new growth. If
new growth is less than 8 inches every year then there is a problem.
be damage from borers. It could also be from stress such as a lack of water.
Ash Decline Disease
ash has a problem with ash decline disease. For this reason, I no longer
recommend planting any of the Arizona ash trees including Fan Tex. The tops of
the trees could have developed ash decline even though this look is not typical
of ash decline.
Ash decline usually hits one or two branches at a time and
causes dieback and slow growth and leaves scorching. It is also possible it has
sooty canker disease. Borers are usually associated with sunburn of limbs lower
in the canopy. If this tree were topped with a chainsaw it is possible that any
of these three possibilities could be a problem.
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| Dieback of ash due to Ash Decline |
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| A severe case of ash decline on Modesto ash |
is a goner and it will continue to slowly decline in coming years. I would
recommend that it would be removed. If this is borers or sooty canker disease
then some pruning might help it recover. If you decide to keep this tree, I
would have a qualified arborist selectively remove the damaged parts of this
tree. Certified arborists know how to prune trees and improve their ornamental
value.
Fertilizer Injector
getting part of what they need through an injection system that deliverables
mineral fertilizers.
Rock Mulch
successfully growing ornamental trees in desert soils. If these soils are
covered in rock mulch then the soil is probably low in organic content. The
organic content can be very important to ornamental trees growing in desert
soils. Rock mulch causes desert soils to slowly become less and less organic
over the years. Mineral fertilizers will not solve this problem. Either
covering the soil with woodchip mulch that decomposes or continually adding
compost to the soil will work. As this soil becomes more “mineralized” over
time the tree may continually decline.
compost to the top of the soil and water it in. You would do this once a year
for the next three or four years but it is a slow soil improvement process.
This is all hinged on whether you have rock mulch or not. The faster option is
to make vertical holes with post hole diggers throughout the root area of the
tree and backfill these vertical holes with compost. This gets the compost
mixed into the soil much faster and produces faster results.
applications of systemic insecticides may be her only solution to the problem.
In any case, someone needs to make a decision about what the problem is which
determines the course of action.