Soil Testing - How To

Judging from the response in the stores about custom programs, this week’s article about how to take a soil test might be of some help. I like to compare a soil test for a gardener to a blood test for a doctor. When I have a physical, my doctor has me take a blood test about two weeks in advance. She (I have a lady doctor) has time to look at the results and make recommendations based on the results by the time I get there for my appointment.

If the blood lab mailed me the results directly or I picked the results up from the lab, I’m sure I would not be able to tell if my good cholesterol was high enough and my bad cholesterol was low enough. What is the ratio of these two numbers? Are my thyroid, liver, and gizzard working properly? Am I getting enough vitamin A, B, C and D? Are they in the right ratio? What is my blood sugar? I end up paying the blood lab over 500.00 for the lab fees, and the doctor her fee for her interpretation of the results, which usually goes something like this - eat like a vegetarian only in very small portions and exercise like an Olympic athlete.

The custom program is similar to the doctor’s visit. When most people look at soil test results from the lab, they comment on the soil pH. They never comment on the buffer pH, which is more important in determining lime recommendations. In all my years of working with soil tests, I have never heard a customer comment about calcium to magnesium ratios, or it looks like I need 5 pounds of ProMag 36 per thousand square feet to get the 1.8 pounds of magnesium I’m lacking.

 SOIL TESTS

Turf grass areas

Proper interpretation of soil test results depends upon collecting a representative sample of the soil. Soil samples can be taken at any time of the year.  Samples are most easily collected using a PVC pipe, garden trowel or spade.

¨       Each soil sample should be a composite of subsamples collected from randomly selected spots within the chosen area.

¨       Soil Sample should be 3 inches deep straight down.  These samples should be equal parts of the first 3 inches of soil.  Avoid pie shaped samples that have more of the 1^st inch of soil and less of the 2^nd and 3^rd inches.

¨       Take 5-10 subsamples for relatively small areas (less than 1000 square feet) in home lawns.

¨       Collect the subsamples in a clean plastic pail, mix the soil thoroughly, and put about one cup of this mixture in a sample bag.

¨       Remove grass, thatch and debris from sample.

¨       One sample per lawn should be good unless you have different types of soil or grass.

Landscape Beds

¨       Soil Sample should be 6 inches deep.

¨       Repeat the steps above.

¨       Please remember to record the location of your samples

(Rose bed, flower bed, shrub bed etc…)

Test results include

¨       pH, Buffer pH (when needed), Available Phosphorus, Exchangeable Potassium, Calcium Magnesium, Cation Exchange Capacity (CEC) and Percent Base Saturation

With recommendations for:

            Nitrogen, Phosphate, Potash, Magnesium and Lime - based on plant type and use

¨       Sodium can be tested for an additional charge. Very important in Lowcountry. We see a lot of high sodium yards in areas that you would not expect sodium to be an issue. Many wells around here also have high sodium (salt) in the water they put out.

¨      Other tests are available including tissue samples; however, these are our most common two. 

Spring is Upon Us

Well, I got called out over the weekend for mentioning the dreaded mole in my last article, and I did not go into the details on how to control them in the article. For the long version, go to possumsupply.com under the Horticulture Hotline tab and look in the archives, or go by your local Possum’s Landscape & Pest Control Supply near you for a handout we have for mole management.

The quick and dirty method involves three steps. Be sure to do these steps in order.

1. Kill the mole. Traps, proven baits (Mole Patrol, Talpirid, etc), smoke bombs.
2. Manage the food source. Sevin or Aloft granular are very effective for managing the food source of the mole. Many products do not kill sub surface insects, so be sure to use an insecticide that does.
3. Repel new moles from your yard. Holy Moley (granular) or one of the liquid mole repellent products will help deter new moles from entering your yard and occupying the old tunnels.

If you have liriope, holly fern, cast iron plant, pampas grass or other ornamental grasses, this is the time to cut them back.  A sharp pair of hedge shears will do a nice job on the larger stuff, and a lawn mower with a sharp blade will take care of the liriope.  Mexican heather and other burnt back perennials could also be sheared at this time. 

Using Neem Oil now will help kill over-wintering insects as well as adults.  This product also controls certain diseases.  Insects and disease love the new foliage that your plants are getting ready to put out, so kill them before they munch on or damage your new foliage.  This product is organic and very safe for the environment.

Your trees and shrubs are going to do most of the growing for the season during the next month.  Put out fertilizer so they will have plenty of food to put out new foliage and grow.  17-00-09 a 100% slow release fertilizer, or many of the organic products in combination with SeaHume will be a sure way to get your plants off to a good start in 2013. 

If you have any perennial insect problem plants (white flies-gardenias, scale-magnolias, scale-camellias, scale-hollies, lace bugs-lantana, aphids-crepe myrtles…), try Dominion Tree and Shrub.  This product is a drench that lasts a long time in the plant, so you don’t have to worry about spraying weekly. 

If you have not put out your preemergent product for your turf and beds, consider one that contains Dimension for its long reach back potential. Be sure to you use the proper amount of Dimension for this area. There is some low active ingredient Dimension in the area (ai amount 0.1%, 0.13%, or 0.15%) which is fine if you spread the proper amount of product; however, not everyone realizes this (ex. If a 50 pound bag of a 0.20% Dimension covers 10,000 square feet, then a 50 pound bag of a 0.10% Dimension only covers 5000 square feet). Do not be fooled by the low bag price.

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

Spring Time in the Lowcountry

What a beautiful weekend we had this past week! I finally took the time to do some work in my yard, and I was glad I did. Many of my deciduous trees (trees that lose their leaves) are either just starting to put on new leaves or still naked. The green weeds are easy to spot in the lawn or beds (yes, I get weeds too). Insect inventory, especially scale, is easy to evaluate at this time. Any sooty mold left behind from last year indicates other insects. With the recent rains, a search for any mosquito breeding areas was easy to do. I hate to ask this, but does anyone have moles?

Right now, before your deciduous trees put on new leaves, is an excellent time to take a close look at them. If your trees are larger, it is a great time to get a professional tree company in to look at them. Look for crossing and rubbing limbs or limbs that are growing towards the middle of the tree. Look for limbs that have died or look unhealthy.

By pruning these limbs now you can direct all the new leaves and growth to limbs you want to keep long term, and not waste the energy of the tree to put on new leaves that you are going to remove later.

When your tree is naked, vines growing up into the canopy are easy to spot along the trunk of the tree. Since the tree does not have any leaves, these vines are easier to remove than when the tree and vine have leaves. I pull these vines away from the tree, scrap off some bark and apply my “vine killer” to the open wound.

Weeds growing beneath the tree are easier to spot and deal with if you have a low branching deciduous tree. My fig tree has these big leaves, so once the leaves come out, it is very hard to spray a herbicide underneath the tree without hitting the fig tree’s leaves. Spray now before the flush of leaves.

In the beds my main weed to deal with was wild onions. Wild onions are not controlled by preemergent herbicides; therefore, this weed was no surprise. I did see a perfect triangle of chickweed in one of my beds, indicating that I missed a spot last fall while I was applying my preemergent herbicide. It always amazes me how many weed seeds are waiting to germinate if you miss them with a preemergent herbicide.

If you have any Asiatic Jasmine or Ivy that has grown into areas you do not want it, right now, while it is putting on young tender growth, is going to be your best time to control it.

If you have been plagued by black sooty mold in the past, right now, apply Dominion Tree & Shrub as a drench to these plants to control the insects that produce the black sooty mold. Get it out now to protect the new foliage from insect attack. Insects, like us (cabbage, spinach, lettuce), like that young tender foliage.

The cooler nights have given us a longer window for preemerge products. Get them out now for less hot, gnatty, summertime weeding and competition for your plants.

"Green" Killers 3

The last 2 articles about “green” products for the industry raised some questions, concerns and comments from readers of the Horticulture Hotline. If you missed these articles, you can find them at www.possumsupply.com under the Horticulture Hotline tab.

The concern came from this statement, “IC3 can also be used safely on docks for spiders, mosquitoes and gnats. Bees, wasps, flies, and biting flies are also on the label.” This statement was cut and pasted off the product’s information sheet (with permission), since it does not technically have a label because it is exempt from EPA. A beekeeper was concerned that Possum’s or myself was advocating the killing of bees.

We are not advocating the killing of bees at Possum’s. My sister and cousin are beekeepers. I just had some of my cousin’s honey over the weekend -  tasty. Having worked in the Citrus industry and other areas of agriculture, I certainly understand the important role bees play in the food chain. With the declining bee population, try not to spray on or near blooming plants, and try to limit your spraying when bees are foraging or in the treatment area.

Most spiders are also considered beneficial, so if you would like to have them around (which I generally do and I almost lost my finger to one), no worries. Possum’s or myself is not advocating the wholesale slaughter of spiders either. I’m just trying to provide information.

The fact that IC3 can be used on or around docks is what differentiates this product from many others, and is why I included this statement in my article. There are a lot of docks in the Lowcountry. Many products now days have aquatic setbacks, IC3 does not have these restrictions.

The use of InVade BioDrain in a house with a septic tank also came up. All of the products in the InVade product line are safe for septic tanks and sewer systems. The Invade products help to reduce grease and solids in the tanks and are considered beneficial. InVade SeptiTreat is a great product to apply every 3 months to your septic tank. The InVade blend of microbes digest fats, oils, grease, carbohydrates, proteins, cellulose, and urea (InVade BioZap is great for cat litter box odors, I am told).  There are many formulations including foams in this product line.

The cool temperatures have given us a longer period of time to get out our preemergent weed control products in our lawn and bed areas. If you are getting the spring itch, now is a great time to apply SeaHume, Cotton Burr Compost and other organics to your landscape.

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