Horticulture Hotline 10/29/18
By Bill Lamson-Scribner
With the strange weather and record breaking attack of the
worms we had this year, the turf has been through a lot of stress. Cold, dry
period, rain period, dry period, and insect (chinch bugs, army worms and other
worms) outbreak stressed out the grass. Fall fungus, whether you call it Large
Patch or Brown Patch, is a regular occurrence as the grass goes into dormancy
in the fall and when the grass comes out of dormancy in the spring. With some
moisture, now is the time it hits in the fall, especially since the grass is
stressed!
Before we get into the nasty subject of fungus, I hope you
all experienced the sweet smell of Tea Olives last week. It was like they all
exploded open at the same time where I live and the smell was wonderful! I also
noticed my Cassia was blooming right on time for Halloween.
All fungus diseases must have three factors line up for
there to be an active problem. This is referred to as the disease triangle.
There must be a susceptible host (your grass), a favorable environment (in this
case cool nights, grass going into dormancy….), and the disease must be present
(in the soil in this case). When all of these conditions are met, the disease
strikes your grass. Once the grass is damaged, weeds take over the damaged areas.
The quick fix would be to apply T-Methyl throughout the
yard. T-Methyl is a systemic fungicide that gets into the plant (grass) and
protects it. Getting a flu shot would be a human equivalent. You want to do
this before you get the disease, just like the flu shot.
Your grass, trees and shrubs (the hosts) must be healthy to
fend off disease. A soil test and a program for feeding them the proper
nutrients the plants (grass) require will help insure your plants have what it
takes to fight off disease. Just like people in third world countries dying of
diseases that would not be an issue in countries with better diets, your plants
need food to defend against disease.
If you have ever noticed Holly Fern, Aucuba, Fatsia, or Cast
Iron Plant growing in full sun that looks burned, you have witnessed a plant
growing in the wrong place that has a fungus. These same plants planted in deep
shade would not get this disease. Grasses planted in deep shade or wet areas
will be more susceptible to disease because they tend to like plenty of sun.
For Large Patch (Brown Patch) disease in turf there are some
cultural practices you can do to lessen the effects of this disease.
1. Correct drainage problems.
2. Fill in low areas.
3. Manage thatch layers. Cotton Burr Compost will help with
this as well as SeaHume and other organic products. Core aeration and
dethatching will also help. Proper fertilization with slow release products
helps minimize thatch.
4. Manage compacted areas. Core aeration, Cotton Burr Compost
and SeaHume will also help with compaction. If the area is a high traffic area,
stepping stones, a sidewalk or some sort of path might be a better long term
solution.
5. Water as little as possible and still maintain a healthy
grass. Wetting agents will help you water less and save money on your water
bill. Wetting agents will help water penetrate the soil surface so there is
less run off and will help cure minor drainage situations.
6. Good air movement is important in managing all diseases
in the landscape.
7. A sharp mower blade is always a good idea.
8. Mowing at the proper height for your grass species.
9. Proper amount of sunlight for the grass you are growing.
10. Last but the most important, proper fertility program
based on a soil test for your grass species.
If you are a “Soil Geek” like me, time for the fun stuff.
Large Patch Fungus is a soil - borne fungus, so if you build up beneficial
microorganisms in the soil, they can compete with the disease organisms. We
have heard many success stories from homeowners and landscapers who have
lowered or eliminated their disease problems by using SeaHume and Back To
Nature products (Cotton Burr Compost, Nature’s Blend, and Flower Bed Amendment)
in their yards. These products increase beneficial microorganisms in the soil competing
with the bad microorganisms and improve the soil’s structure.
We also have been getting good results from people applying Neptune’s Harvest Organic Crab Shell product. Crab Shells
are high in chitin. Nematode eggs and the outside of fungus are high in chitin.
By putting this product in areas where you have the disease, you increase the
chitin eating bacteria in the soil. These bacteria then feed on the disease as
well as the nematode eggs.
Serenade is an organic product that contains the bacteria
Bacillus subtilis. This bacteria competes with Large Patch fungus as well. We
have also heard many success stories involving these products.
By combining the cultural practices along with the Back To
Nature products, SeaHume, the Neptune’s Harvest Crab Shell, and the Bacillus
subtilis, you should be able to “fix” your Large Patch issues, instead of
applying a chemical band aid.
Always read, understand and follow product label. The
product label is a Federal Law.
