University of Vermont Extension
Department of Plant and Soil Science
Summer News
Article
STAKING DAHLIAS AND OTHER JULY
GARDENING TIPS
Charlie Nardozzi, Senior
Horticulturist
National Gardening
Association, and
Dr. Leonard Perry, Extension
Professor
University of Vermont
Staking dahlias, proper watering of
tomatoes, and fertilizing blueberries and container plantings are some
of the
gardening tips for this month.
Don't let the wind or heavy rains
knock your dahlias to the ground. Stake individual stems or place
several
bamboo poles around a large plant and wrap twine around the poles to
provide
support. If staking individual stems,
use cloth or other materials (not twine) so not to cut into
stems. Tie at several places up the stems, including
near tops, otherwise they may break at these points in heavy winds.
You can get some great
deals on perennials now at garden centers, and even if you don't have a
spot
ready for them in the flower border, plant them in the empty spaces in
the
vegetable garden when you pull out broccoli and other early crops. You
can
transplant them into their permanent locations in the fall or spring.
Visit
specialty perennial nurseries every few weeks to see what is in bloom,
so you
can have flowering perennials in your garden at these times too.
You'll find a list of such Vermont nurseries
online (pss.uvm.edu/ppp/vpdgli.html).
Dark leathery spots on the blossom
end of tomatoes is likely to be a condition called "blossom end rot"
that's caused by uneven watering. Mulch will help moderate the
fluctuating
moisture levels that nature provides, and it's not too late to spread
some
around your plants.
Most poppies resent transplanting,
so a good way to propagate Oriental poppies is by root cuttings. Once
the
plants have dried up, dig up pieces of root and cut them into smaller
pieces.
Plant these sections, and sprouts will form this summer. By next year,
you'll have
new flowering plants.
Now through the end of summer is a
good time to divide bearded iris if they've gotten too large, flower
less, or
have gotten weedy (there's no easy way to weed them). Dividing
every 2 to 3 years helps lessen soft
rot and borers. When lifting the swollen roots (actually underground
stems
called "rhizomes") cut off any rotten parts, especially if they
contain white "worms" (iris borer larvae). Separate the sections
naturally by pulling
apart, not cutting. Cut leaves back to
six inches to help offset the loss of roots.
Replant in full sun, in well-drained soil. Make sure the rhizome
is planted near the
soil surface or the plant likely wont bloom next year. Keep
watered well.
Blueberries benefit from an acidic
fertilizer each year. Apply 1/2 pound of ammonium sulfate when the
bushes start
blooming, and another 1/2 pound four to six weeks later. If the leaves
turn
yellow with green veins, they may have an iron deficiency. Applying 2
to 3
ounces of ferrous sulfate or iron chelate around the base of the plants
will
help correct this.
Frequent rains leach fertilizer from
the soil of container plantings, so they need to be fertilized more
often than
plants in the ground. Mix liquid fertilizer into the watering can and
use it
weekly. Don't fertilize when the soil is very dry or it can burn the
roots, so
you may need to water plants first, then water with the fertilizer
solution.
Return to
Perry's Perennial
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