Q. I think you addressed this not too long ago but I give
your Saturday articles to my neighbor so I’m not sure what you said. The attached photos show two trees the builder put in my
front yard two years ago. I think they
are Texas Ash?
I have three yellow emitters and now water these trees
twice per week for 15 minutes. (I can’t
remember how many gallons the yellow ones due in an hour)!
A. Ash trees don’t like the heat all that much. All of
them including Arizona ash. So surrounded by rock (even though it is five feet away from the trunk)
is not the best thing for it. The roots of this tree can’t keep up with the demand by this tree for more water. The main reason you are seeing the leaves burning on
the outside (leaf scorch) is either because the soil needs improvement or the
soil is staying too wet or both.
If you can make that basin covered in wood chips about
three feet wider from the trunk it will help. Rake the rock back, get more
scalloped pavers and make it bigger.
Also, the wood chips should be about four inches deep. Keep the wood
chips from the tree trunk about six inches.
It helps to put a thin layer of compost on the soil
surface under the wood chips. If this is a burden then sprinkle it on the top
of the wood chips and water it in with a hose. Mixing it into the hole at
planting time should have been done at planting time but some of the less
expensive plantings (I have heard rumors of this happening with some “special
deals” from nurseries) don’t use much amendment at planting time or not much mixed in the
soil or the holes are dug too small or all of the above.
I am not sure how you are watering that tree (one of the
ash). There needs to be AT LEAST four drip emitters to that tree at planting
time about 12 inches from the trunk and enough water applied to wet the soil 18
inches deep each time you water. After the first couple of days the watering
should NEVER be daily. The first couple of days daily watering is okay to get
the soil wet and get rid of air bubbles. The soil needs to dry out between irrigations.
Use a four foot
piece of rebar from Lowes or Home Depot to judge if watering is deep enough. If not, water
more minutes or add drip emitters or get some that deliver more water until it
gets that deep.
In mid summer three times a week is plenty if they are
all alone and no other plants for the ash tree roots to get water from. Right
now once or maybe twice a week is plenty. In about two or three years you better add more
drip emitters in another ring out past these emitters about 18 inches away.