- Make sure the irrigation system is working. Run a test cycle, walk around and
unclog or replace nozzles, spray jets, and emitters. In this dry heat, some
species with large thin leaves like avocados and loquats will get toasted,
especially if there is wind. Even if the soil has optimal moisture, the water can't
move from the roots to the leaves fast enough to keep them from drying out.
Wetting the leaves frequently during peak heat will cool them off, raise humidity,
and reduce the damage.
- Washing the leaves discourages mites that thrive in hot, dusty, and dry
conditions. I've seen Japanese black pines with deep green needles where the
sprinklers hit the foliage regularly, but with yellow leaves above the reach of the
spray where the mites had sucked the chlorophyll out.
- Keep suckers pruned off. Suckers are sprouts that originate from the base of
the tree. On grafted trees, its important to keep them pruned or you will get
trunks of root stock forming.
- Prune vigorous rogue sprouts. Sometimes sprouts form in the spring that grow
way faster than everything else. If they are badly located, prune them out
completely. Otherwise, pinch the terminal bud or clip them back to a node or
side branch.
- Prune to reduce the length and weight of overextended branches. Rapid growth
at the branch ends can exert enough leverage to cause them to break. Be sure
to leave enough exterior and interior branches to provide shade for the bark to
prevent bark death from overheating. Foliage on the canopy interior helps the
branches grow thicker and stronger.
- Palms are in full bloom right now. It's a great time to remove the flowers, flower
buds, and dead leaves. Remove as little green as possible to preserve health
and vigor.
- Prop the branches of your fruit trees. Nothing is more disappointing than to
have a heavy crop of peaches break the tree apart. Drill holes at a 30° angle into
old tree stakes and insert large nails to act like hooks.
- Maintain the mulch layer under the tree canopy. Remember that trees drop parts
of themselves on the soil to make the kind of soil they need to have. The stored
energy in the leaves, bark, and twigs feeds the soil web of life that transforms
the soil into good habitat for tree roots. Remember, leaves are called leaves
because you're supposed to leave them under the tree. The mulch conserves
moisture and recycles nutrients. Grass clippings are good mulch, too. Why pay
to plant, water, fertilize, and mow the lawn, pay to throw the clippings away—and
then go and buy mulch. Keep mulch a few inches away from the trunks so that
area can dry out.
For help or more information, call your local ISA Certified Arborist®. You can
find us at Trees are Good online.