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by Rett Davis | |
Gardening Q&A by Rett Davis appears in
Alamance County's daily newspaper, The Times-News,
every Sunday in the Accent section. Each week's installment is
posted to this
website, beginning with January of this year. Scroll to the bottom of
this page to navigate to other Gardening Q&As. Please contact
Rett via e-mail with questions
or
comments in regard to this column.
Question:
I have been under my house to check on some drainage
problems. While under there I noticed that several of my floor joists
are turning black and the insulation was wet. Is this something I
should be concerned about?
Answer:
I alluded to this problem of mold and mildew last week as
another one of the disadvantages of a wet summer. Many basements and
crawlspaces have flooded or experienced excess water drainage this
summer. Moisture can cause serious damage to the structure of your
home. Wood decaying fungi will only decay wood with a moisture content
above the fiber saturation point, which is 30 percent by weight. Wood
with a moisture level above 20% is subject to decay and should be
closely watched. Our goal should be to keep wood under 20% moisture.
The only way to monitor this is use a wood moisture meter. It is a good
investment. I use one periodically to monitor the wood under my house.
I suspect what you are seeing is just a surface mold or mildew. This
will come from a short term wetting and does not cause structural damage
to the wood. Nonetheless, mold and mildew on wood does indicate high
moisture and prolonged periods of high moisture may support the growth
of wood decay. Efforts need to be made to increase air circulation
under the house and to eliminate the source of the excess water. We are
developing several handouts that we can mail homeowners on mold and
mildew control in and under houses. Call us for a free copy at
570-6740. If you are interested in purchasing a moisture meter, they
are available from Forestry Suppliers at 1-800-647-5368. We use the
Protimeter Mini C at work.
Question:
Soon after I mow my lawn there is a bright green grass that
comes up in spots. It is easy to pull up but seems to be throughout the
lawn. I have also noticed it in some of my shrub beds. Can you tell me
what this is and how to get rid of it?
Answer:
I suspect what you have is nutsedge. It is mistakenly called
'nutgrass'. The leaves are yellow green and slender. It does grows
very fast. Nutsedge is a perennial plant that sprouts each year from
underground tubers. This weed will spread throughout the yard and in
landscape beds by way of its rhizomes. At the end of each rhizome is a
tuber. A single plant may produce hundreds or several thousand tubers
in a season. There are many species of nutsedge in North Carolina.
Yellow, purple, and green kylinga are commonly found here. The
preferred method of identifying them is to look at the seedhead.
However, in a mowed turf environment the seed head is never allowed to
develop. Large infestations of nutsedge in a lawn require a broadcast
treatment of a selective herbicide. Manage (halosulfuron) and MSMA
products can be used when the sedges have reached the three to eight
leaf stage. A second treatment 6-10 weeks later will be needed when
using Manage. MSMA products will need to be applied twice, 7 to 10 days
apart. These herbicides are available through professional lawn care
companies. Because the timing of these sprays and the cost of the
material, it is best to use a professional lawn care service to
eliminate this troublesome weed.
Question:
I need to reseed my lawn this fall. It is covered in
wiregrass now. Is there time to kill the wiregrass and still get my
lawn sown?
Answer:
Time is running out to kill wiregrass or bermudagrass. The
herbicide Roundup or its generic equivalent is the preferred herbicide
to use. It will take 3 weeks to do its job. A second application is
often needed. If wiregrass is not totally eliminated before reseeding
it will only return next year and begin to spread out again. Because
there is plenty of soil moisture, wiregrass is still actively growing
and will absorb the herbicide quickly. Spray now using a 2% solution of
Roundup. Your goal is to get your fescue seed planted before the middle
of October. By the way, the generic equivalents of Roundup, or
glyphosate, have proven in research trials to be equal in performance to
Roundup. The generic verisons are sold under various trade names and
are great values.
Question:
I maintain several landscape accounts that have lawns that are
primarily crabgrass. I want to convert them to fescue this fall. How
do I deal with crabgrass that is there now?
Answer:
One option is to use a herbicide like Roundup (glyphosate) over
the entire lawn to eliminate the crabgrass and all other weeds. Once
the lawn is totally brown, aerovate or till the soil to prepare the
seedbed. Apply the necessary amounts of lime and fertilizer prior to
soil preparation. Another method is to use a relatively new herbicide
called Drive. Drive will kill mature crabgrass and not interfere with
the seeding of fescue. Drive is herbicide that is registered for
postemergent control of both smooth and hairy crabgrass, white and hop
clover, dandelion, foxtail, and dollarweed. The addition of methylated
seed oil is required for control. Regular crop oil is not recommended.
The beauty of this product is that it can be used before or after
seeding or overseeding a turf area and it will not significantly
interfere with the turfgrass seed germination and growing. It can be
safely used with tall fescue varieties. The exception would be fine
fescues unless it is part of a seed blend. But don't forget to prepare
the soil so there will be good seed/soil contact for your new fescue to
get off to a good start. Drive is available at BASF dealers.
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If you have any horticultural questions, please direct them to Rett Davis