The long days of summer are upon us. The bugs, humidity and heat
can make a grown person
seek the shelter of air conditioners. You may be miserable, but
what about your trees? Should
you bring them a cool drink?

Summertime trees have full, functional sets of leaves. Besides
shading us from our ample
sunlight, leaves take in carbon dioxide and churn out tree
food.

They make food best just after they expand to their full size
and before the pests start nibbling,
sucking and invading. For trees, now is a great time to be
alive.

Soon, fungi will take up housekeeping. Multiple generations of
insects and other crawly things
will move in. And all sorts of animals will hang around for the
comfort, shade and food trees
provide.

All too soon, the tree’s bounty will go to feed many other
mouths, processes and organisms.

Healthy, structurally sound trees have plenty to share. Trees
that have been neglected, abused
and damaged have little food for anything but survival.

As far as the bugs go, trees shelter the good and the bad under
the same canopy of leaves and
around the same roots. Under some conditions, the bad things
reproduce fast. Only the good
bugs and the environment can control the fast-growing
populations of bad bugs.

A tree is a mini-ecological system with checks and controls for
living things. Under stressful
times, tree-damaging creatures can gain an upper hand.

For trees, it’s not the humidity. It’s the heat. High relative
humidities mean a tree needs to
spend less on water uptake and control. Leaves don’t lose water
as fast. With plenty of
moisture in the air, nighttime dews and fogs reduce water
loss.

Even on humid days, the humidity drops quickly with rising
temperatures. If leaves lose water
to the air faster than roots can absorb it from the soil, the
leaves shut down. They take a noon
siesta that ends when the roots catch up in supplying water.

Leaves begin work as the sun climbs 5 degrees above the horizon
and closes down at day’s end
when the sun falls below 5 degrees from the horizon. It’s always
a long summer work day for
a tree leaf.

Watering trees when they need it helps stressed trees make a
living. During even short drought
times, watering can greatly help young and old trees. Water is a
tree’s most valuable
commodity in summer.

Water evaporating from soil and tree surfaces provide some
cooling. Without water to make
food or cool themselves, trees can overheat. Be neighborly.
Provide a drink for your trees.

The summer heat forces a tree to use more of its food just to
stay alive. For every 18-degree
increase in temperature above 40 degrees Fahrenheit, a tree’s
respiration needs (or food use)
doubles.

At the same time, the tree’s food-making machinery breaks more
often and becomes less
efficient. In fact, at higher temperatures, one of the gas-
capture systems in tree leaves
mistakenly starts grabbing oxygen instead of carbon dioxide.
This costs the tree more food to
correct.

Next spring, you’ll be able to see how well your tree survived
this summer. That’s when
tree-food shortages, damaged tissues and health problems can be
finally tallied.

Is your tree gaining growth to survive and thrive another
season? Or will this summer be the
year when your stressed tree finally evaporates into the
environment from whence it came?

You can help save trees through timely and tree-literate care. A
summertime dream under the
spreading branches of a healthy tree can be well worth the
effort.