Monday, February 3, 2020

The Fungus Among Us


Horticulture Hotline 02/03/20
By Bill Lamson-Scribner

While walking and driving around it seems that brown patch/ large patch/ Zoysia patch has invaded the Lowcountry. As the cooler weather comes and the grass growth rate slows down, large patch / brown patch / zoysia patch fungus will begin to show up in our lawns. This disease is always present in the lawn, it just manifests itself when the environmental conditions are right and your grass cannot outgrow the damage. Without any sustained cold temperatures, this disease is slowly spreading across lawns as the temperatures that favor its growth keep coming into play. Our temperatures keep creeping into the high 60’s even though it is winter. Brown patch loves temperatures in the 60”s.

Since this disease is a big problem in the Lowcountry, knowing that it is a soil borne disease can help you with control strategies.  Being a soil borne disease, you know that it will reoccur in the same areas year after year.  There are not any spores flying through the air like many of your leaf spot fungi, so the disease is easier to control.

As a soil borne fungus, if you map the areas that you have the disease, you can concentrate your control efforts (dollars) into a smaller area, putting less control products into the environment.  If your yard is 5,000 sq ft usually you might have a few infected areas which might total approx. 500 ft.  Instead of buying control products to treat 5,000 sq ft, you can concentrate your efforts into the 500 ft (i.e. 10% of your total yard).  If Large Patch was an air borne fungus with spores, you would have to treat the entire yard because air borne fungi spreads a lot quicker than soil borne fungi.

As your grass is going into dormancy and the temperatures begin to cool at night, large patch is ready to attack your grass. Large patch will go inactive when the temperatures get very cold; however, it will become active again when the temperatures favor the disease. If you have discolored areas in your yard that appear to be a disease, check with someone that knows. Even if it is during a cold phase and the disease does not appear to be active, you can still put out a systemic fungicide for protection. Our soils do not get so cold that the plant will not absorb the fungicide with its roots. Remember treating a fungus with a systemic fungicide is like getting a flu shot – you do it preventatively before you have the disease. In this case, when you want the disease to stop spreading.

 A good granular one-two punch control strategy is T-Methyl and Strobe Pro G (all systemic fungicides that get into the plant).  Use these products in areas where you have had Large Patch previously at the preventive rates and intervals recommended on the labels. Be sure to use T-Methyl with Strobe Pro G, so you are switching chemistry classes and modes of action. Good control early on can help avoid flare ups in the spring also.



Large patch usually likes wet, heavy thatch, improper nutrition, and/or compacted soils.  Culturally you need to manage your irrigation system, raise any low areas, and correct drainage problems.  Reducing thatch (at Possum’s we have a great organic granular product for controlling thatch), maintaining proper fertility levels, and aerating to alleviate compaction, will also help control large patch. A healthy turf (following soil test derived feeding schedule) with a soil with a lot of bio-diversity (use of cotton burr compost, SeaHume and other organics) has shown to help manage this disease.  

Always read, understand and follow product label. The product label is a Federal Law.

Monday, January 27, 2020

Crepe Myrtles / Winter 2020


Horticulture Hotline 01/27/20
By Bill Lamson-Scribner

I got a call yesterday about mosquito control around soccer fields. It is the end of January! Not usually what I would consider prime mosquito season. The weather is crazy. I’m enjoying the smell of my neighbors’ and my tea olives during the warm spells! The fire ants are mounding above ground when they would usually be below ground at this time of year.

The question about pruning Crepe Myrtles and other plants seem to top the list of questions for this week. The butchers are out there! The time is now for getting in your soil test, so you can amend the soil by spring time. Do you have any disease prone plants (roses, etc.) that could benefit from a little sanitation? What is the population of moles in the Lowcountry? What is the population of moles in your yard? Have you applied Neem Oil for overwintering insects and disease?

Crepe Myrtles are the most abused tree in the landscape. Since they bloom on new growth, someone “topped” them a while back and notice the flush of new growth and the prolific blooms. These heavy blooms are supported by wimpy 18 – 24 inch sprouts that just developed that growing season and are the diameter of a pencil. When it rains, the bloom catches water and becomes even heavier. The bloom will hang down and eventually the wimpy new growth supporting the bloom will split off tree leaving an open wound for insects and disease.

Instead of “topping” the tree to increase blooms, a good fertility program will accomplish the same thing without ruining the beautiful natural branch structure of the tree. A soil test and program can guide you to the right fertilizer for your tree. Have you ever seen a Crepe Myrtle in the winter when the leaves are gone, and sense the tree’s embarrassment, like a dog with the cone on its head? A tree that has been “topped” is standing there naked of any foliage with these big nasty swollen knobs at the end of the branch, like huge warts. The tree that is pruned correctly is standing there naked and proud, like a nude Greek Statue.

The correct pruning for a Crepe Myrtle involves removing dead limbs and crossing limbs. Any limbs growing toward the middle of the tree are good candidates for removal. If a limb is growing to the outside of the tree let it be. Opening up the center some for sunlight penetration and air movement is always a good idea to help prevent disease. Sometimes Crepe Myrtles, being a multi-trunk tree, can have too many canes growing from the ground, and one of these needs to be removed. Removing these canes is best done while the tree is very young; however, you can prune these canes out once the tree is older.

There is a very rare occasion that a landscape designer orders that a Crepe Myrtle should be topped. Under certain circumstances usually involving safety concerns or visibility concerns a designer will recommend keeping the tree at a certain height. When I worked on Hilton Head, we had a safety situation by a guard gate that required us to “top” the Crepe Myrtles; however, we did not “top” the other Crepe Myrtles in the project. Some businesses want their sign to be seen, and Citadel Mall is practicing pollarding, a type of severe pruning that the Crepe Myrtle and Sycamores can tolerate.

Now days, Crepe Myrtles are available in all different sizes from 3 feet to 30 feet, so planting the right one to fit the scale of your landscape is crucial. Much of this “topping” can be avoided with the proper plant selection and proper fertility. Whoever is planting the tree (or any plant) should look at its mature height and spread. Then plant the right plant for the space.

If you live in Mt. Pleasant, learn the local ordinances because they have laws about the proper pruning of Crepe Myrtles.

After you prune your Crepe Myrtle properly, now is the perfect time to add Cotton Burr Compost as a mulch, SeaHume as a biostimulant and minor nutrient treasure chest, and a tree and shrub drench for insect protection.

Spring is coming. Preemerge?  

Monday, January 20, 2020

Get Ahead of Your Weeds


Horticulture Hotline 01/20/20
By Bill Lamson-Scribner

The Saucer or Tulip Magnolias are blooming, which usually indicates spring is rapidly approaching. In NASCAR terms the pace car is pulling off the track onto pit row and the green flag is waving. If you are more of a swimmer or track person, the starter has said, “take your mark” and is squeezing the trigger. Yes, a new growing season has arrived! The red maples are tasseling, Sweetgum trees are blooming, some Prunus trees are showing color, brown patch / large patch is everywhere, and fresh fire ant mounds are visible.  

The soil temperature indicates that it is just about time to apply preemergent products to your beds and turf. Valentine’s Day and the running of the Daytona 500 are just around the corner. The time to apply the magical weed preventer is coming up fast.

Depending on which Phd doctor you believe, crabgrass germinates when the soil temperature (3 inches deep) stays above 55 degrees (some people say 57 degrees), for 3 straight days provided adequate moisture in the soil. Now some doctors say remains 57 degrees or above for 24 hours at a depth of 3 inches with adequate moisture.  The manufacturers of the preemergent products suggest that you apply the product 2 weeks before the temperatures are right, so you have to be able to predict the future. If you are not in to monitoring the soil temperature and do not have ESP (do people still use the term ESP), Valentine’s Day or the running of the Daytona 500 should work for you.  Spreading a preemergent product now could save hours of spot spraying later.

The turf areas as well as the landscape bed areas will greatly benefit from the use of preemerge products. Not only will the yard look better, but your plants will not have to compete with the weeds for sun, nutrients, and water. If you are controlling weeds with preemergent products, there are less weeds there for you to spray or pull, saving you time. There is also less stress on you trying to find time to control the weeds in your yard later once the weeds have emerged. Control them now with a preemergent control product!

For those new readers of the Horticulture Hotline, preemergent control products kill weeds as they germinate.  The weeds never come up and you never have to worry about them.  Crabgrass, goosegrass, barnyardgrass, crowfootgrass, dallisgrass (seedling), foxtail, annual bluegrass, smutgrass, barley, kikuyugrass, wild oats, bittercress, carpetweed, chickweed, Carolina geranium, henbit, knotweed, lespedeza, marestail, black medic, mustard, oxalis, pineappleweed, pigweed, redroot, parsley-piert, purslane, rocket, shephardspurse, speedwell, spurge, and woodsorrel are examples of weeds controlled by preemergent products.  Small seeded annual weeds are controlled by preemergent products.

Read the label of the specific product that you are using to get an exact list of weeds that the manufacturer has tested and shown to control. Preemergent products applied now do not control winter annual weeds that are already up like annual blue grass. To control annual bluegrass, you would have used a preemergent in August and again in October (this could vary with products and rates).

Clover, Florida Betony, Nutsedge and Dollar weed are not controlled by preemergent control products.  These are perennial weeds. Weed Free Zone is a liquid that will do a good job on controlling many of your broadleaf weeds. The Nutsedge will require a different product and is most likely not visible right now.  It is important to control these weeds now before they go into their reproductive stage.  A weed in its reproductive stage is harder to control than a weed in its vegetative stage. By controlling the weed now you avoid having to deal with more weed seeds next year.

It is very noticeable when you ride through the Lowcountry which homeowners and which businesses used preemergent products last fall at the correct time. One business or home lawn will be nice and brown and dormant without a spec of green in sight. Right next to it will be brown turf mixed with green weeds. Again, it is very important to control those weeds now before they begin to flower.

If you are trying to control weeds in the lawn that are up and starting to flower or seed, mow – wait 2 days and spray – then wait at least another 3 days before you mow again. The mowing will get the weeds actively growing and weeds that are actively growing are easier to kill. If the product is root absorbed, be careful around desirable plants, and water-in properly. If you water in too much, you could move the product passed the shallow root zone of the weed you are targeting.

Always read, understand and follow product label. The product label is a Federal Law.

Bill Lamson-Scribner can be reached during the week at Possum’s Landscape and Pest Control Supply. Possum’s has three locations 481 Long Point Rd in Mt. Pleasant (971-9601), 3325 Business Circle in North Charleston (760-2600), or 606 Dupont Rd, in Charleston (766-1511). Bring your questions to a Possum’s location, or visit us at http://www.possumsupply.com. You can also call in your questions to “ The Garden Clinic”, Saturdays from noon to 1:00, on 1250 WTMA (The Big Talker). Saturday's show is replayed Sunday from 11:00 - Noon.