THE AFTER EFFECTS OF DROUGHT
By Dr. Leonard Perry
Extension Greenhouse and Nursery Crops Specialist
University of Vermont
The damage is done. Most parts of Vermont
experienced a drier than usual summer this year that
affected many perennials, trees, and shrubs. It doesn't
matter how much rain we get now. It may be too late
for some plants.
So, just what can you expect now? Is there
anything you can do to help the still living?
If you have very dry sites, like sandy
soil, medians near pavement, or new plantings, you may
have already lost some plants. There's not much you
can do here except replant and help plants get established
in future years.
But don't be too hasty. A little patience
may go a long way. What appear to be dead may actually
have living tissue underneath the bark or in the ground.
Scratch the bark of trees or shrubs to see if it is
still green underneath. It's best to wait, if you can,
until next spring and see if these plants leaf out.
The same applies to woody plants that
are living but may appear to have "dead" branches.
Again, use the fingernail test to see if these still
have some life. If so, wait until spring to prune. For
perennials, prune off obviously dead growth and branches.
If the whole plant appears to be dead,
mark it to remember its location, as it may produce
new shoots next spring. Browning on the leaves may not
be aesthetically pleasing, but leave these are they
still are helping the plant.
Whether you have a sandy or heavier soil,
top dressing with compost will help. Organic matter
is key to soil health and soils retaining moisture.
Generally, the more, the better. This also will help
lawns that may have suffered or died during a drought.
Speaking of lawns, you may wish to rent
an aerator or get some aerator blades for a mini-tiller
to help heavy, baked soils. For clay, as well as lighter
sandy soils, you might want to top seed grasses in early
fall prior to topdressing lightly with compost. If seeding,
make sure you can keep lawns watered until the new seeds
germinate and begin to establish.
Keep all plants watered as well as possible.
This means a good soaking. Light watering fosters shallow
roots, which are quite susceptible to drought. If you
only have a few perennials, or a shrub, watering by
hand or a slow trickle from the hose may work. For a
whole perennial bed, overhead sprinklers are often the
best. Just water early in the day to allow foliage to
dry before night.
From late September into October keep
evergreens, such as rhododendrons, well watered. This
will help them get through winter with a minimum browning
Soaker hoses also work on many perennial
beds and shrubs. These are porous rubber hoses that
allow water to soak right into the root area and not
on foliage. These don't foster leaf diseases, and they
don't waste water to evaporation and other areas as
do overhead sprinklers.
Don't fertilize woody plants in fall as
fertilizing in early fall may promote non-hardy growth,
and in late fall it does little good. However, many
herbaceous perennials will respond to fall fertilizer
(an organic, slow release form works well) by going
into the winter hardier and with more food reserves
for the following year.
Just keep in mind, too, that what happens
one year with woody plants, such as this year's drought
stress, often shows up the following year or even for
several years after. You may see plants with less vigor,
increasing dieback such as from winter injury, or more
susceptibility to diseases and pests.
Many woody and herbaceous perennials that
bloom early in the season set their buds the previous
year. These include lilacs, peonies, and many daylilies.
Even the later bloomers may have less growth next year
as a result of the stresses this year. So, keep an eye
on these, and if they are not at their best this coming
year, don't despair but again, have patience!
If in any given year, your plants don't
bloom or perform well, ask yourself what happened last
year. Were there stresses? Or, did the plants bloom
quite well and now are taking a year to recoup? Understanding
what happened the year before will help you provide
proper care--and extra help if needed--for your plants