Monday, June 18, 2018

Biopesticides Are Getting Better And More Popular

Horticulture Hotline 06/18/18
  Bill Lamson-Scribner

Biopesticides (also called bioscience products) are pesticides that are found in nature. Do you remember studying in middle school how the black walnut tree exudes its own preemergent herbicide (juglone that causes an allelopathic effect) to keep other plant life from growing underneath it and competing with it?  This is definitely the way of the future! 

The most common biopesticides that you might have heard of in the past would be pheromone traps for catching flies or Japanese beetles.  Pheromones are natural chemical attractants (usually sexual) that animals as well as insects produce. You put these attractants on a glue board to attract flies and Japanese beetles and they get stuck. Bt or Bacillus thuringiensis is bacteria that controls many different worms, caterpillars, mosquito larvae or Lepidoptera insects.  Diatomaceous earth is a natural contact insecticide derived from microscopic plankton or algae with silica skeletons.  Roaches, ants, fleas, and snails walk across this product and it causes abrasions to their exoskeleton and they dry out and die.

Many of the major chemical manufacturers are spending more money developing these types of products (finally) because they are easier to get approved through the EPA, saving them money in the long run. The EPA doesn’t require so of the expensive testing for organic products. One of our main manufacturers recently introduced an insecticide that is approved by the National Organic Program; however, they didn’t market it as an organic product because some people in the industry feel that organic products do not perform as well as the chemical counter parts. At Possum’s, we hear all the time the organic products last as long as the chemical products.

Most bioscience products are very specific to certain pests; however, now many products are being introduced with a much broader label.  In some cases, it is required that you use them more frequently because the product breaks down in the environment very quickly.  Diatomaceous earth on the other hand lasts a very long time. It is important that you know the life cycle of the insect or pest that you are after because some bioscience products only attack the pests at a certain stage in their life cycle. 

Some bioscience products that we had had a lot of success with include; Harpin protein, Neem Oil, Spinosad, beneficial nematodes, various oils and insecticidal soaps.  Other bioscience products called bionutritional products or biostimulants that we have seen great success with include; humic acid (Possum Hume), seaweed products (liquefied seaweed and sea kelp products), and amino acid products.  SeaHume (a combination or seaweed and humic acid) is a proven performer in the Lowcountry.

To give you an example of a bioscience product, Harpin protein (found in Mighty Plant) is a bacteria’s (fire blight) waste product (poop) that is sprayed on the plant.  The plant thinks it is being attacked by a bacteria so it goes into its defensive mode.  The plant’s cuticle thickens preventing attack from certain insects, fungi and bacteria.  This cuticle thickening also conserves water.  The plant also flowers profusely in an effort to create seeds to perpetuate its species (war time babies) and also grows a larger root system.  Since most people grow plants for flowers, this is an obvious benefit.  A plant that has been treated with Harpin protein is more drought tolerant, has better flowers, has better foliage, can resist certain fungus and insect attacks, and has a stronger root system than an untreated plant. 

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 You can also call in your questions to “ The Garden Clinic”, Saturdays from noon to 1:00, on 1250 WTMA  (The Big Talker). The Horticulture Hotline is available 24 / 7 at 

Monday, June 11, 2018

Knowing How Big Your Yard Is

Horticulture Hotline 06/11/18
By Bill Lamson-Scribner

Knowing the square footage of your grass areas and bed areas are key to applying any fertilizer or control product correctly. Whenever we sell a bag of fertilizer at Possum’s we are going to ask, “how big is your yard?” You have to know if you need one bag or more than one bag. Some of our bags might be able to treat your yard twice. That is nice to know because that cuts the price per application in half, and also lets you know you still have product waiting in the garage for your next application. With the nice weather we are having, now is a great time to get out there and measure the yard.

I can remember several times hearing different variations of this same answer to my question while at the counter at Possum’s. “How many square feet is your yard?” Rough answer,” well, last year I put out that bag that covers 5000 square feet and it was perfect for my yard, so I must have 5000 square feet.”  Sorry, wrong answer.

Based on a pound of nitrogen, we sell 50 pound bags that cover as much as 23,000 square feet and as little as 1000 square feet. Unfortunately, the bag does not know the size of our yards or how fast we walk.

In the old days, yards were mostly square or rectangular, and they were easy to measure. Now most yards have curvy bed lines that sweep across the landscape, making them more difficult to measure. If you can break the yard up into little squares or rectangles, and measure the length and the width then you can get your square footage. Length multiplied by width will give you your square footage. Add up all the squares and rectangles that you measured the square feet of, and you will come up with the square footage of your yard.

If this sounds like total “Greek or Geek” to you, ask a landscaper, a realtor,  a landscape architect, someone that works with floors or carpets, an engineer, a construction worker, someone who pours driveways, or anyone else that regularly needs to measure the square footage of something to help you. Your plat map from when you purchased your house might help as well.

Now, there are even websites that you can log onto and they will tell you the square footage of your yard. Of course, I like to do it the old fashion way – length times width.

I know this measuring seems like a pain, but most of us stay in a house for several years or decades. A little pain spread over several years of having very useful information is worth it.

Once you measure the yard, put the measurements in about 5 to 10 locations throughout your house, your car (so you have it with you when you go to buy product) and the garage, so you do not lose them. I have learned over the years that I put information like that in one “special place” so I do not lose the information. I then forget where that “special place” is!
Yes, this rain has been perfect for mosquitoes! Yesterday, I was helping my mom with her hand pump up sprayer, so my hands were full. The mosquitoes knew it and launched a full attack. Buzzing around the ears where I could not see them and on the arms where I could see them but my hands were full so I could not swat them! It was already lightly raining, so I will launch my counter attack at a later time. First, I will attack their breeding sites (making sure there is no standing water), then I will go after them directly.

Japanese beetles are still eating their favorite plants and trees.

EcoVia (NOP Compliant) or Cyonara will work great on both of these insects and many  more insects.

Monday, June 4, 2018

Tropical Storm = Gray Leaf Spot - Non-Chemical Tips For Control

Horticulture Hotline 06/04/18

Wasp, biting flies, flies, fire ants, fruit flies, Japanese beetles, termite swarmers and mosquitoes – Tis the season. It is scary the amount of fire ant mounds you see when you get into an area that is not managed for fire ants.

The rains and high tides have the mosquitoes are out in full force. Protect yourself! 

Between pop up thunderstorms, people going on vacation, and people just not mowing enough, gray leaf spot has exploded on St. Augustine grass. I am seeing gray leaf spot on Zoysia as well.

Gray leaf spot (Pyricularia grisea) goes with St. Augustine like grits go with shrimp! Or like chinch bugs go with St. Augustine! To battle gray leaf spot, you are best employing many cultural practices and using limited control products if necessary.

Gray leaf spot looks like someone burned or dripped acid on the leaves of the plant.  There are little oblong spots on the leaf.  Eventually, these spots grow together and the leaf blade dies.  Whole areas of your grass can disappear at once when these leaf blades die.

Culturally there are several things to do to minimize your problem with gray leaf spot.  This disease likes high humidity and excessive nitrogen fertilizer.  To help alleviate the high humidity, mow your grass to a level that seems abnormal to St. Augustine.  Try to get it down to 2 ½ - 3 inches depending on the variety of St. Augustine grass.  Also try to mow every 3 – 5 days with a bagger.  This mowing will help get sunlight down to the crown of the plant, drying the leaf blades as quickly as possible.

With mowing it is always hard to get someone to modify the frequency of cuts. “The landscaper only comes every 7 or 14 days” or “I mow every Saturday morning”, is what I usually hear. If you don’t want to cut it yourself (saving a trip to the gym and I have been told a cold beer is extra good after mowing) in between visits by the landscaper, maybe you could hire a neighborhood kid or your kid to just mow the grass. No edging, blowing or weeding, just a quick mow.

Another alternative to you mowing is applying a growth regulator to your turf. These products work great at slowing your turf’s growth rate. Growth regulators are used extensively on golf courses and athletic fields. Growth regulators do a great job of managing your turf’s growth rate on your home lawn as well.

Consider trimming trees or shrubs to increase air movement through your yard.

This fungus like most fungi likes hot humid weather.  Minimize the amount you water as much as possible.  Wait until your lawn is getting a blue/green color and your foot prints stay in the lawn after you walk across it before you water. Unfortunately, you can not control rainfall as easily. In the Lowcountry, afternoon thunderstorms are a way of life, so keep the grass mowed as low as you can so it will dry out quickly. 

Hold off of the nitrogen fertilizer until you can get this disease under control.  If you need some color, you could add a product like Possum’s Minors to give you some green without all the nitrogen. Watch starving your grass because a malnourished yard is more susceptible to disease. Very low rates of an organic fertilizer or cotton burr compost might help it recover.

At Possum’s, I know we have had several customers that swear they control this disease by using our wetting agent with biostimulants, cotton burr compost, and / or SeaHume along with the above cultural practices. You will need to water less with the use of these products, and wetting agents help keep the leaves on the grass plant dry. These products are not fungicides, but customers have seen a correlation of using them and having less disease issues.

If you have to resort to a control product, make sure the product is labeled for Pyricularia grisea.  There are many leaf spot diseases on labels of control products but only certain products work on gray leaf spot on St. Augustine and Zoysia. We had one customer come in that had been applying a product that controlled Drechslera spp. and Biopolaris spp. leaf spot; however, the product was not labeled for Pyricularia grisea (watch where you shop). 

Honor Guard and Heritage are systemic products that you spray. Since this is a leaf spot fungus, the sprays seem to give good coverage over the leaf blade.  If you would rather use a granular product, Prophesy (same active as Honor Guard and Banner), Heritage Granular, and Fame are granular systemic products that are absorbed through the roots and will do a good job for you.

  Bill Lamson-Scribner can be reached during the week at Possum’s Landscape and Pest Control Supply, 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).  Fax your questions to 406-2700 or e-mail them to your newspaper’s editors. You can also call in your questions to “ The Garden Clinic”, Saturdays from noon to 1:00, on 1250 WTMA  (The Big Talker).