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Old 03-02-2003, 08:57 PM
Allegra
 
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Default How, when and why to apply dormant spray.

Hello everyone,

Different strokes for different folks, but spraying dormant spray to protect
the roses is a good practice whether you are in Alaska or in Florida.

The reasons to spray roses with dormant spray are various and different in
any case but I venture to say that they all have a common cause: to ensure
that the plants are healthy and free of both fungal diseases and insects.

Most spores from fungal diseases will overwinter both in leaves and debris
at the surface of the rose. All the good and well established cleaning
practices
can be for naught if some pathogens are present either under the leaves left
on the bushes or in the ground, regardless of where you are. They are the
trouble
in the making for the coming year for the roses (and you).

Copper compounds are used as a fungicide on dormant roses. The two most
common products are copper sulfate and Bordeaux mixture, a copper sulfate
and hydrated lime mixture. Copper has a toxic effect to many fungi and
algae. When applied as a dormant spray, these copper compounds help to
eliminate overwintering pathogens. Spray roses with dormant spray using the
same spray technique used on trees and hedges: up from the bottom, then down
from the top.

Horticultural oil is the other material that you could use in a routine
dormant spray program. The dormant spray oil actually suffocates insects
that overwinter on roses and has a similar effect on insect eggs that may be
present. Both horticultural oil and copper compounds can be purchased from
your nursery or as we do, from a nearby feed store that provides for farm
needs. Frequently, the copper and horticultural oil mixture may be applied
at the same time. Follow label directions carefully and wear protective
clothing when applying pesticides.

If you want to have a plan for February here is a suggestion:

Apply dormant spray as indicated above starting at the bottom of the rose
and coming back from the top. Make sure to spray around the base of the
plant
as well to catch any "stray". We strip our roses early on in January by
doing maybe
10 to 20 every day until the whole garden is done. By January normally there
isn't
much to strip (take that back for this January) and clean very well around
the beds
or pots. The first application of dormant spray (Bordeaux) is done then plus
a spray of Wiltpruf and we check the ground for any kind of trouble. This is
the time when we also apply pre-emergent weedkiller. You are always grateful
to remember this in June ;)

In February we again make a second pass with the dormant spray to make sure
that anything that survived the first spraying is taken care of by the
second. It sure helps with all fungal diseases and we have seen very little
insect damage on the roses, except the holes of the carpenter bees and those
are welcome in our garden.

Here is a link to Sheridan Nurseries with some info about dormant spray and
its uses.
http://www.sheridannurseries.com/Gar...3mainframe.htm

Good gardening everyone,

Allegra