We planted two of these last spring as part of our foundation planting
in an northwest facing area that gets about 4 hours of afternoon sun but
is otherwise shaded. They've fallen prey to all kinds of insects which
seem to just laugh off the systemic insecticide that the knowledgeable
lady at the garden center suggested. I think they have root weevils,
plus various caterpillars and other bugs. All the other plants we put
in at the same time are doing fine (a burkwood viburnum, pyramidal yews,
rosebud azaleas and Blaaw's Pink azaleas.)

My question is this: if I pull out theses miserable plants, what do I
have to do to the soil to make sure that replacements don't have the
same problems (root weevils in particular).

I'm thinking of putting in more pyramidal yews where these were.

Thanks for your ideas!



Also, any suggestions for

Insufficient information.
Location / zone
Soil ph
Moisture

wrote:
Insufficient information.
Location / zone
Soil ph
Moisture


Location: Western Massachusetts, close to VT/NH border. Zone 5 but barely.
Soil Ph slightly acid. In addition, I mulched with coffee grounds last
year.
Moistu It rained all last summer and fall and we had snow cover all
winter. However, the drainage is very good where these were planted
since it is the foundation and there are curtain drains underneath.

Jenny wrote:

Location: Western Massachusetts, close to VT/NH border. Zone 5 but barely.
Soil Ph slightly acid. In addition, I mulched with coffee grounds last
year.
Moistu It rained all last summer and fall and we had snow cover all
winter. However, the drainage is very good where these were planted
since it is the foundation and there are curtain drains underneath.

Most rhododendrons including chionoides are acid loving plants. Your
soil may be slightly acidic, but near a foundation it will be alkaline
due to the lime in the foundation. Wet conditions on an unhappy plant
will make it susceptible to most anything. The plant should thrive if
given more sun and acidic soil. When healthy they transplant very
easily. They have very shallow roots.

The bugs were in the soil already, either in the soil from the garden
center or your soil. Weevils live in the ground but come out at night
and chew on the edges of the leaves. This is a very common problem in
many areas.
--
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Visit my Rhododendron and Azalea web pages at:
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Also visit the Rhododendron and Azalea Bookstore at:
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Cheers, Steve Henning in Reading, PA USA Zone 6

Stephen,

I put a lot of coffee grounds around these plants all last summer,
hoping that would help acidify the soil. What else would help?

More sun isn't an option here. There are about 4 hours in the afternoon
and that's it.

Any suggestions as to what to do about eliminating those weevils? I'm
assuming they came from the garden center (which grows its own plants)
as none of my 4 other azaleas or 2 yews show any signs of damage. I've
been spraying once a month with a systemic insecticide as directed by
the "expert" at the locally owned Farmers Ag coop. After 2 sprayings,
I'm not seeing much progress. I've also hit them with "rose spray" to
take care of the caterpillars which also showed up this spring.

The rhodos did put out big clumps of leaves this past week, so they're
still alive.

Any detailed suggestions would be very much appreciated.

Stephen Henning wrote:
Jenny wrote:


Location: Western Massachusetts, close to VT/NH border. Zone 5 but barely.
Soil Ph slightly acid. In addition, I mulched with coffee grounds last
year.
Moistu It rained all last summer and fall and we had snow cover all
winter. However, the drainage is very good where these were planted
since it is the foundation and there are curtain drains underneath.


Most rhododendrons including chionoides are acid loving plants. Your
soil may be slightly acidic, but near a foundation it will be alkaline
due to the lime in the foundation. Wet conditions on an unhappy plant
will make it susceptible to most anything. The plant should thrive if
given more sun and acidic soil. When healthy they transplant very
easily. They have very shallow roots.

The bugs were in the soil already, either in the soil from the garden
center or your soil. Weevils live in the ground but come out at night
and chew on the edges of the leaves. This is a very common problem in
many areas.

Jenny wrote:

I put a lot of coffee grounds around these plants all last summer,
hoping that would help acidify the soil. What else would help?

Powdered sulfur is best. If there are signs of chlorosis (Yellowing of
a leaf between green veins) then acidity may be increased by adding
flowers of sulfur (powdered sulfur) or iron sulfate. I add 1 tablespoon
of sulfur powder around the base of any plant showing signs of chlorosis.

More sun isn't an option here. There are about 4 hours in the afternoon
and that's it.

That will reduce the number of flower buds but is not a big problem.

Any suggestions as to what to do about eliminating those weevils? I'm
assuming they came from the garden center (which grows its own plants)
as none of my 4 other azaleas or 2 yews show any signs of damage. I've
been spraying once a month with a systemic insecticide as directed by
the "expert" at the locally owned Farmers Ag coop. After 2 sprayings,
I'm not seeing much progress. I've also hit them with "rose spray" to
take care of the caterpillars which also showed up this spring.

Leaves chewed on edges is a symptom of chewing insects. Most are
nocturnal feeders and can be found at night with a flashlight. The most
prominent chewing insects on rhododendron and azaleas are the Black Vine
Weevil and Strawberry Root Weevil. Feeding is done at night. Specimens
may be collected at night for identification. The major damage is caused
by weevil larvae which girdle the roots and kill the plant. Larvacidal
drenches may be used to kill them but are of limited effectiveness. A
more effective approach is to use nematodes. They are very effective
against weevils. Foliar sprays are very effective at controlling adult
weevils when leaf notching starts. Foliar sprays must be repeated until
no adults emerge. Since weevils feed at night, you can hand pick adult
weevils at night using a flashlight. Since weevils spend the daytime in
the soil and come out at night to feed, you can paint the trunk with
Tanglefoot to stop them, but make sure no branches are touching the
ground. Other chewing insects include caterpillars, cut worms and
loopers.

The rhodos did put out big clumps of leaves this past week, so they're
still alive.

This is a very good sign. Resist the temptation to fertilize. I good
fertilizer like Hollytone now is OK but none later.

Good Luck!
--
Pardon my spam deterrent; send email to
Visit my Rhododendron and Azalea web pages at:
http://home.earthlink.net/~rhodyman/rhody.html
Also visit the Rhododendron and Azalea Bookstore at:
http://home.earthlink.net/~rhodyman/rhodybooks.html
Cheers, Steve Henning in Reading, PA USA Zone 6