Friday, August 26, 2016

Crape Myrtles

If you drive around Memphis, you'll be hard-pressed to find a home without a crape myrtle in the yard. Although in the past few years (since we've been battling crape myrtle bark scale), I've seen people remove them (or at least attempt it: they tend to re-sprout from the root). Still, I think most of us still love them, in spite of this new problem they're having. The young plants can be a bit gangly for the first few years, but if you are patient, they can become something truly beautiful. The branching structure of some varieties is a work of art. 

Consider, this huge, old 'Natchez' cultivar that belongs to my neighbor. He estimates that it is about 30 years old. While its lovely white blooms are almost finished, its bark and beautiful branching structure makes it a great tree year-round.

Here is a closer look at that massive, branching trunk. 

Natchez is one of the larger crape myrtle varieties, growing to over 30 feet tall. Jack and I bought one 4 or 5 years ago. One of the things we liked about it was its exfoliating bark, which peels away each year to reveal smooth, cinnamon colored wood. It takes several years for a young tree to develop this trait. 

In this picture of our young tree (at right), you can see three older trunks that have exfoliated and two younger ones that still have their immature color. Some of the peeling bark is visible at the bottom of the picture.

It's amazing how many different varieties of crape myrtles are available. In addition to an assortment of bloom colors, you can have your choice of size (3 ft. to over 30 ft), leaf shape (rounded short leaves to longer thin leaves), and bark texture. 

How did all these choices become available? I learned a lot about this subject from the speaker at this month's Master Gardeners meeting. Greg Touliatos of the Urban Earth garden center, spoke about crape myrtle bark scale, and in his introduction, gave us some history of the crape myrtle. 

The first species of crape myrtle, Lagerstroemia indica, was brought to the United States over 200 years ago. While a beautiful plant with long-lasting flowers, this variety has a smaller, bushy form and is prone to mildew and winter die-back. Around 1950, U.S. Arboretum personnel acquired seeds from Japan of a different species of crape myrtle (Lagerstroemia faurier), which has a taller, more upright form, is more cold hardy and less susceptible to mildew. They began to experiment with growing this species, and soon began to develop hybrids with the most desirable characteristics of both species. These hybrids are usually what we find at most nurseries today.

For years, we've enjoyed the beauty of these hybrid crape myrtles and considered them to be "bulletproof," pest-free and requiring little care. However, in the early 2000's, a new form of bark scale that infests crape myrtle found its way into the U.S. and began making its way across the country. Scientists still have much to learn about this new scale, but there is suspicion that some varieties of crape myrtle, specifically those bred from the Japanese species Lagerstroemia faurier, may be more susceptible than others.

The neighbor's huge crape myrtle (shown in the pictures above) was infested two years ago with crape myrtle scale, and he had it treated at that time. It has completely recovered and he has not seen any new infestation. So I suppose there is hope that we will not have to treat our crape myrtles every year. Only time will tell what the ultimate impact will be of this new type of scale. Until we learn more, crape myrtle lovers will need to be vigilant about inspecting their trees for infestation.

The presentation on crape myrtles will be given again in September at the Urban Earth Saturday seminars. Check their website or Facebook page for more information.

Saturday, August 20, 2016

Update on Armyworms

Yesterday we discovered that armyworms have infested our lawn. Apparently, there are a variety of chemicals that are effective against armyworms, so I called Dr. Chris Cooper at the Extension Office to ask his recommendation. I had one of the products he suggested (Ortho Bug B Gon) in the garage, and I also took a trip to Lowes to purchase one of the others (Spectracide Triazicide). While in Lowes, I ran into a friend who is the Plant Specialist in the garden center. I told her why I was there and she remarked that people had been coming in all day to buy treatment for armyworms. 

Yesterday, Jack mowed the grass and raked where the clippings were heavy. Since armyworms tend to feed in the morning and late afternoons, we waited until about 6:00 p.m. to spray. The Spectracide chemical I bought was a hose-end, ready-to-spray formulation that covered 5,000 sq ft area. This was enough to spray the area where we saw the caterpillars and a wide margin around that area. A large number of caterpillars like we have will eat all the green in an area (except the broadleaf weeds that we wish they would eat), then systematically march to the adjacent green areas to continue wreaking destruction. Thus, the name armyworms. I read somewhere that they can increase the margins of an affected spot by as much as 3 feet overnight. 

I suspect that the lawn services in our area are treating entire yards, not selected areas as we did. Treating the entire lawn makes sense for a lawn service because armyworms can move quickly across the turf. In addition, they may already be in areas that are not showing damage yet. But Jack and I wanted to the minimize use of chemicals as much as possible, while still achieving some control. As homeowners, we have the ability to check the turf every day and spray as needed.

One indication that we may need to do additional spraying is an unusually large number of birds on the lawn. We did not spray the backyard (where no damage was evident yesterday), but this morning there were about 6-8 robins feeding there. I went out to check the grass but did not see any caterpillars. Birds can serve as an early indication that armyworms may be present, but they cannot eat enough to control a large infestation.

The other yardwork we did today was to put the final application of fertilizer and a pre-emergent herbicide on our lawn. (This summer, we have used more lawn chemicals than we usually do, hoping to encourage a thick lawn that will not require a lot of chemicals to suppress weeds in the future.) Had we not been visited by armyworms, we probably would have waited a few more weeks for this, but we wanted to encourage re-growth in those bare spots and to stop the germination of weed seeds that are now getting plenty of sunshine. Or will be soon when we get rid of these clouds. We put those chemicals down this morning, hoping that the forecasted rain will come in this afternoon and water them in for us.

I'm curious about how widespread this armyworm outbreak is. I live in Germantown, and many people in my neighborhood have them. What about your area of the county?

Friday, August 19, 2016

Army Worms in the Lawn

For several days, I have noticed an area of our lawn that looked a little brown. Yesterday, a neighbor mentioned (on the Next Door computer site) that her back lawn had turned brown, almost overnight, and her lawn service had said it was fall army worms. So I checked our brown spots, which also seemed to have grown a lot bigger.  

Sure enough, there were numerous little caterpillars in the lawn. 
Here is what the caterpillars look like. When you see them in the lawn, they are usually curled in a tight ball, and they appear greener than they look in these pictures. 

I did some internet research, and it seems that they do not kill the grass, just make it very ugly for awhile. Some information I came across suggested that treatment was not necessary, especially if the infestation was not heavy. But our infestation seems to be pretty heavy, so we will treat with an insecticide. The recommendations I found often suggested mowing the grass before applying an insecticide, so Jack is out there now mowing, even though we normally would consider conditions too wet to mow. Apparently, the window to kill the caterpillars is short. They grow fast and then burrow themselves into the ground for the winter. In the spring, they hatch into moths and lays eggs which turn into caterpillars that eat your lawn next year. 

I will share with you what I've learned about treatment methods in my next post. Now I have to mix up insecticide.

Wednesday, August 17, 2016

Trapped Inside the House by Mosquitoes

What a weird, wet growing season this has been! One of the negative effects of an unusual amount of rain has been a perfect environment for mosquitoes to thrive. Today, I walked out to the back of our garden to see if the systemic insecticide I applied last week to our beautyberry had begun to work (it had not), and in those few minutes, I was swarmed by mosquitoes. I didn't put on insect spray because I thought I'd be moving quickly and would be out and back before they realized I was there. Wrong. I'm scratching my hands and arms as I type. The rest of me was covered up. I'm just thankful that we have not yet had any instances of locally-acquired zika virus in our area but I'm afraid it is just a matter of time. 

On a more pleasant note, on my walk to check on the beautyberry, I paused long enough to snap this picture of a stand of cardinal flowers. (That's probably when the mosquitoes got me.)  How these cardinal flowers got here is something of a mystery. I have cardinal flowers growing in an area nearby but these came up last fall (apparently from seed) in an area about 20 feet away from the other plants. This spring the little rosettes made a thick mass. I transplanted some of them to other places, gave away some, and tried to find new homes for the others. When I was not able to give them away, I just let them grow in the spot where they planted themselves and they are now beginning to bloom. For some reason, they don't seem as pretty this year as in past years. The hummingbirds feel the same way, I suppose. Normally, cardinal flowers are hummingbird magnets but I have not seen as many hummingbirds around this year.

While I'm complaining, I'll also mention that I have not been pleased with my annuals this year. I planted far fewer annuals this year than I normally do, but none of them have done well. The annual vinca I planted died. The petunias I planted are living but look scraggly and blighted. Looking around the neighborhood, it appears that no one is having much luck with annuals this year. How do the flowers look in your neighborhood?

Friday, August 12, 2016

Check your Beautyberry Bushes

Last night at our Memphis Area Master Gardeners' meeting, Greg Touliatos, owner of Urban Earth garden shop, spoke about crape myrtle bark scale. The talk was very informative and, even though I had thoroughly researched the topic in 2014 when I first discovered the scale on my own crape myrtles, I learned several things. Among them was that these scale are also thought to jump to several native varieties of plants, including the American elm and beautyberry Callicarpa americana).

Since my introduction to crape myrtle bark scale in 2014, I have checked our crape myrtles regularly to be sure they have not returned. So far, so good. But I didn't realize that these pests would move to other species of plants. This morning, I walked to the back part of our garden where we have a beautyberry planted and this is what I found. My beauty berry was not beautiful. It had only a few berries, yellow, sick-looking foliage, and darkened stems. Upon closer inspection, I discovered the cause. The picture below provides a better look at the culprit. 

Greg Touliatos talked at length about how to control crape myrtle bark scale, and the chemical he suggested was the one I had used in 2014. So this afternoon, I mixed up a drench containing imidacloprid and poured it around the shrub. It won't look like much this year (especially considering a systemic insecticide takes some time to kill the insects) but we'll see what happens next year.  By the way, the brand of insecticide I had on hand (shown here) is only one of several brands you can find available in garden centers. 

For those of you who might be lucky enough not to be familiar with these pests yet, click here for additional information on the them. If you have crape myrtles in your garden (or beautyberries), you'll undoubtedly need this information sooner or later. 

Monday, August 8, 2016


My brother is a fan of the herbicide Round-up. He uses it a lot around his farm. I was at his farmhouse recently and noticed a bouquet that his wife had picked from the flowers around the farm. Among the zinnias, butterfly weed, and buddleia blossoms, I spotted a strange specimen.

Here's a closer look at that strange green flower that caught my interest. While adding no color contrast to the arrangement, its odd form added an interesting structural touch.

I asked my sister-in-law, who happens to be a fabulous floral arranger, what that flower was, and she told me that it was an echinacea, deformed by my brother's fondness for spraying Round-up. I know that chemicals can do strange things to plants, but I had never seen this kind of thing. So I went home and posted the picture on the University of Tennessee's Soil Plant Pest Center Facebook page with a question asking about what caused the deformity. Here's their answer:
"This is a disease called aster yellows. It's caused by a phytoplasma; vectored by leafhoppers. Very common on Echinacea. Infected plants are reservoirs of the pathogen and should be removed to slow spread."

I forwarded this information to my brother and sister-in-law, and my brother replied, "so I am exonerated." I replied, "only for this specific incident." I don't think that there is any evidence that Roundup is unsafe, but history has shown us that chemicals thought to be safe can turn out to be otherwise. (Think DDT, BPA, agent orange, etc.) I'm not yet in the "never use" camp, but I like to minimize use of Roundup.

Finally, I want to say kudos to the Soil, Plant Pest Center for being such a valuable source of information. I posted my question on Facebook on a Sunday evening and had an answer less than 5 minutes! While I'm not expecting this speedy service every time, it was an appreciated surprise.

Tuesday, August 2, 2016

An Onion with a Website

Last week my sister shared with me some onion sets of a variety neither of us knew anything about. The sets were tiny little bulbs that grew as a cluster at the top of the onion stalk. Someone had given them to her and the only thing she knew about them was that they were suppose to be perennial onions.

An internet search identified them as Allium proliferum, commonly known as "Egyptian onions." They are also called "tree onions"and "walking onions" because of their growth form. They put up tall stalks like most onions, but at the top of the stalk, these little plants form. If left alone, the stalks fall over and the bulbs take root where they touch the ground  (thus the name "walking onion"). Click here for a website devoted entirely to this variety of onion.

I intended to plant these at the farm in Shelby County where I garden with my brother, but I forgot to take them when I went out there. So I stuck them in a very large container to see what they would do. With the first bunch, I separated the bulbs and planted each one separately. The second bunch, I simply planted as a cluster, thinking that this must be okay since that's how they naturally plant themselves.

I don't know what to expect from them, but I think I should see new growth before fall. Has anyone grown these? If so, I'd welcome  information and/or advice.