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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:
All of a sudden in the last week there has appeared brownish
red spots in my fescue lawn. It seems to be taking over my entire
lawn. The grass is losing its green color and I am worried it is going
to kill my entire lawn. What is happening and what can I do to stop it?
Answer:
I have been seeing this problem for over a month in many fescue
lawns across the county. It is a turf disease called 'red thread' that
infects not only fescue but bentgrass, bluegrass, and ryegrass. The
symptoms are just like you described which include irregular shape
patches of rapidly dying grass. The patches will have a tan color.
Dead leaves are often interspersed among uninfected leaves. The patches
are often widely distributed across the lawn. This disease thrives when
the temperatures remain cool and during prolonged periods of rainfall.
This fungus will kill the leaves of grass within 2 days. Control for
most homeowners is not very easy. Bagging your clippings will help by
removing the fungal threads that would have gone back into the soil.
Upon closer examination of your infected leaves you will see the
characteristic 'red threads' on the tip of many leaves. The severity of
red thread is also associated with low soil phosphorous, potassium, and
low pH. A soil sample taken this summer should identify what kind of
fertilizer you will need to apply this fall to correct deficiencies.
However, you can still have this disease in lawns that are fertilized
and limed on a regular basis. It is even present in my own lawn but
only to a small degree. Hopefully homeowners with irrigation systems
have not turned them on this year. We have had adequate and frequent
rainfall up to this point and home lawns do not need to be supplemented
with irrigation water yet. Overly wet grass only increases the severity
of this disease. As warmer and dryer weather arrives this disease will
be on the wane.
Question:
Our two crabapple trees appear to be wilting. The leaves are
all curled up and drooping. Is this tree dying?
Answer:
Your crabapple is infected with a disease called apple scab.
Although the disease is unsightly, damage to the tree is not usually
serious. Leaf diseases such as this are more severe during periods of
continued cool and wet weather. Many of the leaf diseases I have
written about in the last few weeks such as red thread, fire blight,
black spot, and powdery mildew literally explode when we have springs
like the one we are experiencing. Other diseases are ready to flourish
too but I am saving them for future articles. The best way to avoid
apple scab on crabapples is to plant resistant varieties in the future.
There are many on the market. Those recommendations are listed in our
publication 'Superior Crabapples for the Landscape'. Older trees such
as yours will shed the infected leaves over the coming weeks and then
new leaves will reappear. Fungicidal sprays can be applied next spring
when the leaves are emerging to reduce infection. But it is too late
for this year. Many older trees may be too difficult to spray because
of their size.
Question:
How and when do you prune lilacs?
Answer:
Lilacs in the genus Syringa which are the large flowered
lilacs and fragrant are all pruned the same way. This includes the
common lilac, Persian, and Chinese lilac. Pruning is necessary in order
to continue to have healthy, vigorous plants. There are several ways to
do this. In the winter you can remove 1/4 to 1/3 of the largest stems
close to the ground. Try to maintain 6 to 12 healthy stems. Space them
so the the stems do not rub. Height control can be accomplished by
pruning a foot or so lower than the maximum height you desire. This
should be done immediately after flowering or now. Removing the spent
flowers is not necessary. Tree lilacs should have the suckers removed
that appear from the base. Limit your trunks from one to three.
Smaller varieties such as 'Miss Kim' rarely need pruning.
Question:
There is sap coming out of my young peaches. They are about
the size of a global and there is a clear sticky sap stuck to the side.
What is this?
Answer:
Cut open the peach carefully and you will see a little tunnel.
At the end of that tunnel near the pit is a nice healthy worm. This
little worm is the larval stage of the plum curculio. This insect
entered your peaches shortly after bloom. It is too late to control
this pest for this year. Next year you will need to spray your peach
trees with a Home Orchard Spray or Fruit Tree Spray. Begin spraying as
the blossoms fade and repeat every 7 days throughout the season. Other
pests await your peaches too. Most homeowners will quickly learn that
it is cheaper to buy your peaches than raise them at home.
UPCOMING EVENTS
Mark your calendar for Saturday, June 7th and attend the daylilly show
at Colonial Mall in Burlington. Daylilles of all types and colors will
be on display. Many of which can be grown in your own home landscape.
This show is sponsored by the Central Daylilly Club of North Carolina.
Come out and meet the growers and gain valuable information on growing
daylillies.
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If you have any horticultural questions, please direct them to Rett Davis