From: Gary W. Hickman, Horticulture Advisor
University of
California Cooperative Extension
August 8, 2001
BACKYARD HORTICULTURE
By Gary W. Hickman, Horticulture Advisor
University of California Cooperative
Extension, Mariposa County
In response to our newsletter mailing
list update, we received several questions. Since many are of broad interest,
some of these questions and answers are included here.
Q.
What is the difference between the USDA Climate Zones and the Sunset Garden
Book Zones?
A. The USDA zones are based on winter minimum
temperatures. However, whether or not a plant will grow well in a particular
location depends on many other factors. This includes summer high temperatures,
length of growing season, humidity and rainfall. The Sunset zone system
includes these factors.
Since Mariposa County has a wide range of
growing conditions, we are preparing a list of vegetables and fruit tree
recommendations for different locations. If you would like to help develop this
list, please call our office at 966-2417 and ask for the Garden Survey. You may
also print this form from our web site:
http://ucce.ucdavis.edu/counties/cemariposa Go to “Master Gardeners”, then to “Garden Survey”.
Q.
How can you control Japanese beetles on roses?
A.
Good news and bad news. There are no established Japanese beetle infestations
in California. A very common rose feeding insect, however, is the Hoplia
beetle. It is about ¼ inch long, mostly reddish brown with silver, black or
white markings. The whitish larvae eat roots. The adults chew blossoms,
especially the white and yellow colored flowers. For control, the beetles can
be hand picked. Several chemical controls are effective if applied to foliage
when adults are active. Garden supply stores should have some of these
products, with label directions for use on roses.
Q.
What Eucalyptus tree varieties would do well in Mariposa County?
A. Based on research conducted in other parts
of the state, the minimum temperature tolerance of several varieties has been
established and would be a guide for trials here. In most cases, the more cold
tolerant the Eucalyptus variety, the slower its growth rate will be.
Variety minimum
temperature tolerance
Eucalyptus
grandis 23 degrees (F)
(flooded
gum)
E.
camaldulensis 20 deg.
(river
red gum)
E.
viminalis 16 deg.
(manna
gum)
E.
dalrympleana 10 deg.
(mountain
gum)
E.
gunnii 0 deg.
(Cider
gum)
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