Category Archives: Turf

The Green June Beetle

Recently I noticed a large green beetle in a butterfly bush. It was a dull hunter green color with brown stripes. I’ve seen a few of them in the past but I didn’t know what they were. It didn’t take long to learn that these beetles are green June beetles (Cotinus nitida).

Green June beetles are common to the eastern US, especially in the south. While these insects haven’t received a lot of attention in the past here in PA, they have now been recognized as a turf pest in southeastern and southwestern Pennsylvania.

Green June Beetle

Green June Beetle

The adults are 3/4 -1″ long and have a velvety green to dull brown color with stripes of green with yellow-orange margins. The underside of the green June beetle is either a metallic gold or green. Adults also have a distinct flat horn on the head. The adults are active fliers and sound like a bumblebee as they move through the air.

While the adult can attack some fruits, the real problem of this insect is its larval stage. The female green June beetle lays eggs in turf in the summer and these eggs develop into grubs. The grubs feed on organic matter in the soil and the roots of grass. Active grubs will burrow to surface of the soil in the evening and often leave piles of accumulated soil on the lawn’s surface that look like earthworm castings. While the damage to a healthy lawn is minimal, stressed lawn may be damaged by the grubs feeding habits.

Green June Beetle - Note the Small Horn on the Head

Green June Beetle – Note the Small Horn on the Head

When the weather turns cool, the grubs burrow deeper into the ground and overwinter. They resume feeding in the spring and then pupate in the soil during May and June. After pupating, the grubs are transformed into adults which emerge from the ground to mate and start the cycle once again.

A well maintained lawn will be able to survive the damage of green June beetles. If the grubs are causing a problem, there are insect-parasitic nematodes that can be applied to control the grubs naturally. Also green June beetle grubs are parasitized by a type of digger wasp, Scolia dubia. This naturally occurring wasp can be seen flying above turf with a green June beetle infestation, seeking grubs in which to lay its eggs. There are also chemicals that can control severe infestations of green June beetle grubs. You can check with your county extension agent for recommendations.

I’ve never noticed mounds of soil on the grass from the green June beetle grubs. I also haven’t seen that many adults. It’s obvious that I don’t have a green June beetle problem. Maybe there are enough digger wasps in the area to keep this insect in check. What I do know is that I now can give a name to this beetle – the green June beetle.

2,4-D and Mecoprop-p and Dicamba – Oh My!

Ever since starting this blog, I’ve been more aware of what’s in the herbicides or insecticides that I might use. I’m sure most people just look at what the pesticide controls; I look at what the chemical(s) is (are) and then do some checking to see how it works.

I recently picked up some Weed B Gone Max to use on the lawn. I’ve stopped using the Scotts Step 2 Weed Control plus Lawn Food. When you use this product, you’re applying herbicide to the entire lawn. That makes sense if the lawn is really weedy but the weeds in my lawn are limited to the edges. The majority of the lawn is weed-free. I can’t justify applying herbicide where it isn’t needed.

As a result I’ve started using the Weed B Gone Max spray to apply directly to the weeds. When I looked at the active ingredients, I was a bit surprised. I expected the spray to contain 2,4-D (2,4-Dichlorophenoxyacetic acid) – this broadleaf herbicide has been around for ages. But the other chemicals, mecoprop-p and dicamba were new to me.

Untreated Hairy Bittercress

Untreated Hairy Bittercress

2,4-D, mecoprop-p and dicamba all have the same mode of action. These chemicals mimic the naturally occurring plant hormone indole-3-acetic acid (IAA or auxin). Auxin was the first plant hormone to be discovered and it helps to control and regulate the development and growth of a plant. When any of these three synthetic auxins are applied to a plant, they disrupt the normal growth patterns and cause the plant to twist, the leaves to cup and the stems to crack. Eventually this leads to the death of the plant.

Grass plants are tolerant of artificial auxins because they have specialized cells around their vascular tissue called schlerenchyma which prevent the vascular tubes from closing as the stems twist. The amount of schlerenchyma increase as the grasses grow; that’s why it’s not recommended to apply 2,4-D to a newly seeded lawn – the young grass plants don’t have enough schlerenchyma cells to withstand the herbicide’s action.

Treated Hairy Bittercress - note the stems beginning to twist after herbicide application (one day)

Treated Hairy Bittercress – note the stems beginning to twist after herbicide application (one day)

Artificial auxins are absorbed through the leaves of a plant. That’s why when you’re using a granular formula like Scotts Step 2, you have to apply it when the grass is wet so it will stick to the leaves of the weeds, otherwise it won’t work. The effects of the herbicide can be seen in about a day but it can take up to two weeks to kill the plant.

But if all three of these artificial auxins work in the same way, why are there three of them in Weed B Gone Max and not just one? Come to find out, some weeds are more affected by one artificial auxin than another. 2,4-D is great on dandelion and plantains but not chickweed and ground ivy. Mecorpop-p controls chickweed, clovers and ground ivy and dicamba is effective for controlling chickweed as well but doesn’t control plantains. By combining these three herbicides, overall weed control is better.

So that’s why all three herbicides are in Weed B Gone Max – any one artificial auxin wouldn’t kill all of the weeds but the three together will take care of most weed problems in turf. When I use pesticides, I usually prefer to use just one but in this case I can make an exception. I know what these herbicides do, I understand their mode of action and the combination of three makes sense. But I’m still not going to spray it indiscriminately on the lawn. Spot application makes sure that the least amount of herbicide is used in the most effective way.

The Lawn Mower – It’s Not Just for Mowing Lawn

Last week I mowed the lawn for the last time. Over the years I’ve gotten used to the fact that here in south-central PA, the final mowing of the season is usually in early December.

Besides just mowing the lawn, there were two other chores that I finished with the hold of the lawn mower. The first was dealing with leaves and the other was cleaning up flower beds.

When it comes to leaves on the lawn, some people are out raking every time a leaf falls; others seem to ignore the leaves and let nature take its course. I fall somewhere in the middle. While I’m not obsessed with getting rid of every leaf, I do know that a thick layer of leaves on the lawn can smother the grass. If the layer of leaves is very thick, I vacuum and shred the leaves . (The shredded leaves make a great mulch for the asparagus bed.)

But if the leaf layer isn’t too thick, I use the lawn mower to clean them up.  That was the case last week. The mower did a great job of shredding the leaves and removing any matting of leaves on the grass. Over the winter the shredded leaves will break down and I didn’t have to rake nor did I have to think about what to do with the leaves. I just let the mower do the work for me.

Perennial Bed before Mowing

Perennial Bed before Mowing

By December the perennial beds have finally gone dormant. There are always a lot of dead leaves and stems that I like to get rid of before winter. Some wait to clean the beds until spring, letting the dead plant material serve as a winter mulch. But since the winters aren’t that bad here, I don’t worry about a winter mulch – I just want to clean up the beds.

Perennial Bed after Mowing

Perennial Bed after Mowing

In years past I’ve gotten down and pulled the dead leaves and stems but now I’ve found an easier way to clean the beds. I raise the lawn mower to its highest setting and run it over the perennials. Daylilies are my favorite to handle this way. A couple passes over them and the clumps of dead leaves are shredded and laying on the soil. Chrysanthemums also clean up well this way. By the spring, most of the debris is broken down and any that hasn’t just gets covered with mulch. This trick also works well for cutting down a raspberry bed.

The lawn mower got a workout last week but now it’s tucked away in the garage. The lawn is neat and trim; the leaves are shredded and off the grass; the perennials are cleaned up – three late fall jobs taken care of with one machine. The lawn mower.

The Grass Is Greener

I’ve never been much of a lawn person – grass just never captured my attention. In my mind, if you were planting a lawn, you bought seed, spread it on the soil and watered it until it started to grow. Once it was growing, you were done.

While I wouldn’t say that I’ve developed a love of turf, I do have a greater appreciation for what goes into growing a good lawn. The inherent problem with turf is that it’s a monoculture (the practice of growing a single kind of plant in a given location). Monocultures are hard to maintain because everything in nature wants you’re monoculture to become a polyculture! Every weed that takes root in the lawn is nature’s little challenge to your monoculture of grass. A monoculture needs special care in order for it to flourish.

The foundation of a good lawn is choosing the right seed for the monoculture. I had always thought that grass seed was grass seed – there wasn’t that much difference – but I’ve realized that this isn’t true.

Last fall I replaced the strip of grass growing between the road  and the sidewalk. It had been planted by the people who put in the sidewalk and it was slowly dying. Others in the neighborhood had grass in this same location and theirs was growing fine. I wondered why one lawn would be growing while another was dying. I came to the conclusion that it had to be because of the kind of grass that was growing in each of the lawns. Whatever seed the sidewalk installers used in that space between the road and the sidewalk led to a lawn that couldn’t survive the stresses of the location.

This set me on a quest to learn about grass seed. I found that there are a lot of different seed mixtures available to homeowners. Most of them contain a combination of the standard grasses for the northeast: rye grass, fescue and bluegrass. But within these three types of grass there are different varieties of each which are better suited to different locations. So this time, instead of buying a generic grass seed mix, I went to a local store that had seed formulated for this part of Pennsylvania. It was more expensive but I thought the specialized mixture might be worth the extra cost.

It was a little slow to come up but I expected that – the better lawn grasses tend to germinate more slowly. The grass has filled in and is growing well. Every time I mow the lawn I notice the difference between this grass and the next door neighbor’s grass. Their grass has a coarse texture while the grass I planted has very fine leaves. It’s obvious that we used very different seed mixes! Also the new grass is a deeper green – this might be due to the kind of grass that’s growing, fertilizer usage or a combination of both. All I know is that the new grass I planted looks really good.

Time will tell if this special grass seed was worth the price. Summer drought will be the test to see if it’ll survive. But for now, I’m pleased with the results – the grass is greener on my side of the fence.

Controlling Crabgrass

Early spring is the time of year to prevent crabgrass in your lawn. I just spread Scotts Turf Builder with Halts crabgrass preventer on the lawn. A few years ago I tried going the organic route and used a corn gluten product that was supposed to stop crabgrass. It smelled nice, like masa harina, the corn flour used in making corn tortillas! The problem was it didn’t work very well for me.

Crabgrass

So I’m back to Scotts. The product that I put on the lawn has a high nitrogen fertilizer in it that will help the grass green up quickly. It also has a crabgrass preventer that Scotts calls Halts. I did some checking to find out what  Halts is – it’s the chemical dithiopyr.

In the world of herbicides, there are preemergent and postemergent herbicides. Preemergent  herbicides prevent weed seeds from germinating and/or developing normally. Postemergent  herbicides affect weeds that are already growing.

Dithiopyr is a preemergent herbicide – it doesn’t kill crabgrass that is already growing. Instead it prevents the crabgrass seeds from growing into crabgrass plants. It’s put on the lawn in early spring when the forsythia bushes are blossoming. This is the time to apply dithiopyr because crabgrass seeds haven’t started to germinate but they will begin to grow within the next 2-3 weeks as the soil warms.

I’m fascinated by the way this chemical works. Dithiopyr is a mitotic inhibitor of normal cell division in the germinating crabgrass seed. If you remember back to biology class, mitosis is the process by which cells multiply. During seed germination, mitosis is happening at a rapid rate.  Dithiopyr affects mitosis in germinating crabgrass seeds by inhibiting the formation of the microtubules which are necessary for the chromosomes to separate correctly during cell division.  When dithiopyr is present, the germinating crabgrass seeds are unable to grow into healthy plants because its cells can’t divide normally. And that means no crabgrass!

But whether you care about how this herbicide works or not, the important thing is that it works. If you want to have a crabgrass-free lawn, a preemergent herbicide is the way to go.