“
Some plants, shrubs, and even trees have a very
limited ability to cope with heat or drought stress,
ESPECIALLY DURING LIFE STAGES LIKE FLOWERING OR FRUITING.”
A
s gardeners, we choose plants that
seem like a good fit based on our
experience, or the recommendations of
people like friendly nursery managers
or neighbors with green thumbs and
great gardens. In a predictable world,
that’s fine. But when nature takes
a sharp left turn into unchartered
territory, one option is to choose hardy
native varieties that already have
an affinity for a specific region. They
are less likely to develop problems
for reasons other than unseasonable
weather and may be in a better position
to survive. This is becoming a popular
trend, so there’s plenty of information
about native species for different areas
of the country. Another is to prefer
drought- and heat-tolerant cultivars.
Let’s look at some of the symptoms
plants exhibit when they’re not getting
enough water or are experiencing
heat stress. Then we’ll explore several
ways to avoid problems.
SIGNS OF DROUGHT OR HEAT
STRESS IN PLANTS
High heat and drought often crop
up simultaneously, or drought
will follow a prolonged period of
higher-than-normal temperatures.
Both conditions can have a negative
impact on photosynthesis and
other plant functions. Keeping
a gardening log will help when
closing in on the most likely or
pressing diagnosis. Look for these
early signs of stress on your plants
when it’s extremely hot and dry:
• Wilting leaves and stems
• Dropped leaves, blossoms, or
immature fruits
• Leaves that turn yellow or
appear burnt along their
margins
• Slow or stunted growth
• Curled or rolled leaves
• Bolting (life cycle escalation
from heat stress)
• Blossom-end rot
You can see some of these symptoms
are generic and can have more than
one cause. Making the right judgement
call usually involves observing
several factors operating in concert. It
bears repeating that keeping a garden
journal can be very helpful.
The good news is many popular and
important plant varieties do have ways
to protect themselves when water
is scarce, or temperatures become
damaging, and can recover after limited
exposure to adverse conditions. For
example, to conserve moisture, some
can take up carbon dioxide at night
rather than during the heat of the day
or can store water reserves in fleshy
leaves or roots. Others develop more
robust root networks to search for water.
Research into developing heat and
drought-tolerant cultivars is ongoing,
which will likely result in better choices
at the garden center going forward.
Now, let’s get to the bad news. Some
plants, shrubs, and even trees have a
very limited ability to cope with heat
or drought stress, especially during life
stages like flowering or fruiting. In the
case of fruiting plants, a specimen may
appear to recover and look fine until the
fruits themselves fail to mature, become
stunted, develop split skins, or exhibit
other symptoms. It can be difficult or
impossible for these plants to recover
and perform normally after even one bout
of extreme heat or water deprivation.
Maximum Yield
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