Pests and Diseases: June Bugs

june bugs
Photo courtesy of www.missouribeginningfarming.blogspot.com

 

Just a quick note for those who live in Virginia: those big green beetles that are flying around a couple of feet off the ground are June bugs. They’re not hornets, Japanese beetles or cicadas. And yes, people have asked me if what they are witnessing is an invasion. Rest assured that it’s not. The recent heavy rains have stimulated the bugs to get their rear ends out of the soil. And don’t stress over them…they don’t bite although they will leave a mark on your forehead if they fly into you (don’t ask me how I know!). Chemicals aren’t necessary. They generally are gone before you can reach for the pesticides.

Their life cycle is very similar to Japanese beetles and they can cause damage to your turfgrass. If you want to treat for them, follow the recommendations that I made in this article on Japanese beetles. Or you can just plant more perennials…or vegetables…or shrubs…or trees.

Let me know the funny things that you’ve heard regarding June bugs. My all-time favorite was the concern that they were hornets. If I ever see that many hornets, all you’ll see of me is my tail lights as I pack up and leave. ūüôā Leave me a comment or e-mail me. Don’t forget to like the Facebook page and follow me at Twitter. Happy gardening!

Pests and Diseases: Japanese Beetles

Well, the Japanese beetles are zooming about and hiding out in your roses. They can quickly turn your prized plants into skeletons of their former selves. There are tons of chemicals that people use to kill them each year but is it really necessary? Do we really have to drench our beloved plants in insecticides to withstand the deluge of Japanese beetles? Let’s look at the life cycle of Japanese beetles to determine the best time to treat them.

 

japanese beetles
Photo courtesy of USDA

 

The winged insect that you see flying around in July is the culmination of a full year’s work. The eggs were layed in the soil the previous July or August and quickly hatched into grubs. Those tiny grubs eat plant roots until the temperatures cool down in the fall. At this point, they burrow down 4″-8″ to wait out the winter. In the spring as the temperatures rise, the larvae rise back to the surface where they mature into the adult that eats your plants. Now, thinking about how to successfully treat them, it only makes sense to treat the grubs when they are small in the late summer. In Virginia, August is the best time. If you wait until the spring, the grubs are large (over an 1″) and it takes much more chemical to kill them.

As you all know, I don’t like applying pesticides. As much as I don’t like them and won’t use them in my yard, I understand that many homeowners still prefer to use chemical methods. I would rather educate people so that if they apply chemicals they do so at the proper time instead of applying chemicals willy nilly. I am often asked in the spring what chemicals can be applied to take care of Japanese beetles. People are discouraged when I tell them that missed the boat and need to wait until late summer. At least you all know now.

In regards to more organic methods of Japanese beetle control there are a few options. The first is milky spore. It’s a soil dwelling bacteria that attacks the grubs and then reproduces in the soil. It is slow to establish itself but the magic of milky spore is that it continues to propagate itself without any effort from you. Another control option is trapping. There are the conventional yellow bag traps that have been used for decades and there are all sorts of newfangled ones. I saw an interesting video on a new type of trap that is renewable. I am by no means recommending it since I haven’t tried it but it’s still a great idea that I thought that I would pass along.

If you watched the video, you saw that backyard chickens are an integral part of the system. Chickens are a wonderful means of pest control that should be considered as part of any backyard garden. They provide pest control, manure that can be composted for your garden and “hen fruit”, the name that Joel Salatin has given to eggs.

Is your garden being inundated with Japanese beetles this year? What control methods are you using? Leave me a comment below or e-mail me to let me know. If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me on Twitter. Happy gardening!

Pests and Diseases: Squash Bugs

I hate them. I hate them, hate them, hate them. Squash bugs are my nemesis in the vegetable garden. Hate is a very strong word that I reserve for only the most vile of creatures. Squash bugs fit that description. In past years in the veggie garden, they have decimated the squash and zucchini. Once they finished up there, they moved onto the cucumbers, then the muskmelons and then the watermelons. I hate them.

Squash bugs resemble stink bugs and they smell like them too. Side note: if they release their smell on you, the smell is pretty yucky. But if you get them first and smush them, they smell like green apple Jolly Ranchers. There’s your useless trivia for today. Squash bugs are particularly fond of the cucurbit family which explains why they traveled throughout the garden destroying our veggies as they did. They usually start with squash and zucchini and kill them first. They don’t seem to prefer the cucumbers, muskmelons and watermelons but once the population has exploded, the critters need something to eat. I have to tell you this story about just how bad they were a few years back. The kids had helped get the garden established and took a lot of pride in it. They noticed that the zucchini leaves were wilting and turning yellow so they ventured in to see what was the matter. Once they got close to the zucchini, they discovered that the leaves were covered in squash bugs of all ages…old, new, and in between. They blazed a trail out of the garden screaming the whole way. Hilarious! I didn’t take the picture below but I could have…they were that bad.

squash bugs
Photo courtesy of www.umn.edu

 

If your garden is infected with squash bugs there are several approaches that you can take.

  1. Conventional pesticides – sadly, I’ve taken this route. The ubiquitous Sevin dust was used one year and a chemical containing bifenthrin was used the next year. Neither had very good results. And I felt horrible afterwards…what if a honeybee walked through the insecticide and took it back to the hive…what if the ladybugs pranced through it…what if a praying mantis was looking for dinner at the time…what if, what if, what if?
  2. Trap crops – I’ve read of this technique but never practiced it. I understand the principle but not the logistics. From what I read, you plant a susceptible crop (Zucchini Black Beauty comes to mind) and let the squash bugs take over. Then you treat the trap crop or dispose of it. Sounds good right? BUT if you treat the trap crop, whose to say the beneficials aren’t there trying to feast on the squash bugs? If you dispose of the trap crop, how do you do that so that the majority of the squash bugs are killed? I don’t have the answers…please fill me in if you do.
  3. Hand picking – this works if you have a few squash bugs here and there. If your plants look like the picture above, you better enlist some extra hands and pray for more hours in the day.
  4. Wooden boards – I’ve read that you can lay down boards and the squash bugs will congregate underneath overnight. Then you can take care of them. My problem with this treatment method is two-fold: first, my garden is not at my home…too much shade. Secondly, I have a full time job that requires me to leave the house at 6:15 AM…not much time there to go hunting for squash bugs.
  5. Planning – I had the perfect plan this year to beat the squash bugs. We would plant squash and zucchinis everywhere in the garden and harvest, harvest, harvest. When the squash bugs became overwhelming, we’d pitch the plants and move on. What happened in reality? Pretty much, nothing. Life happened and we have a few¬†squash and zucchini plants. Perhaps this technique will work for someone else…
  6. Diatomaceous earth – I did a post about this wondrous compound yesterday but I haven’t tried it…yet. My only concern with using DE is killing the beneficials too. I’m sure that I’m overthinking this, as is my nature, but it really bothers me to think that I could be killing all of those beautiful creatures.
  7. Chickens – this is the best option…ever…when it comes to getting a handle on squash bugs. Luckily, my garden buddies, Sean and Anna, are raising hens this year. They have six young girls that would love to get in the garden and peck the squash bugs. If you have chickens, let them out to free range in the garden. If you usually keep them in a tractor, you’ll have to let them out so that they can access the base of the plants. The key here is to monitor the hens and only allow them in long enough to get their fill; otherwise they’ll peck all of the veggies that are meant for your plate.

 

So…after all of that, what have you done to control squash bugs in your garden? What has worked and what hasn’t? Let me know so that I can share it with other Mid-Atlantic Gardening readers. Leave me a comment below or e-mail me. If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me on Twitter. Happy gardening!

 

 

 

Pests and Diseases: Colorado Potato Beetle

 

colorado potato beetle
Photo courtesy of www.ca.uky.edu

 

Does this guy look familiar? On our way into church Sunday, my son, Myles, spotted one of these insects and asked “Momma, what is that?”. “It’s a Colorado potato beetle” I replied, wondering why it was there. You know that it’s the season for them when they’re hanging out on the car next to yours in the church parking lot. The name “Colorado potato beetle” may make you think that they’re only a pest of potatoes…it isn’t true. These buggers enjoy all members of the Solanaceae family which includes potatoes, tomatoes and eggplant.

I have found that they do the most damage to my tomatoes when the tomatoes are wee little fellows. Once the tomatoes get above a foot tall, the larvae of the beetles can’t compete with the tomatoes’ rapid growth. Here’s a picture of the larvae…they look nothing like their adult counterparts.

 

colorado potato beetle
Photo courtesy of www.ca.uky.edu

 

But eggplants are usually more of a pipe dream in our garden than a reality. Last year, the Colorado potato beetles stripped the leaves off before the plants had a chance at growing. This year, my gardening partners, Sean and Anna, bought some eggplants with some size on them and they are doing wonderful. Perhaps size makes a difference with the eggplants too.

Potatoes are the creme-de-la-creme for the Colorado potato beetle. I guess that’s fitting considering their name, huh? All types of chemicals have been deployed in the battle against Colorado potato beetles through the years including DDT. Who’s hungry?

There are more friendly ways that you can deal with Colorado potato beetles. Let’s look at a few, after we briefly discuss their life cycle. The beetles overwinter in the soil and then emerge in the spring to lay their eggs. The females lay bright orange egg masses on the undersides of the leaves. When these eggs hatch, the larvae feed on the leaves and after 10-20 days, depending on the temperature, the mature larvae drop from the plants and enter the soil to pupate. After a few days in the soil they¬†emerge as¬†full on adults. This first set of adults repeat the pattern and they finish the season by overwintering in the soil. To the control measures:

  1. Rotate your crops. Due to the fact that the adults emerge in the spring ready to carry on the love affair with your plants, be sure to not plant members of the Solanacaea family in the same plot as last year.
  2. Hand pick the larvae and adults. You can either put them in soapy water or feed them to your backyard chickens. They’re free protein for your girls if you have them.
  3. Floating row covers. These lightweight covers can save your plants from all sorts of insect pests and Colorado potato beetles are no exception.
  4. Bt. If all else fails, you can apply Bt to control them. Make sure to apply Bt when the larvae are small as this is when control is most effective.

 

Have you experienced the misery that comes along with a Colorado potato beetle infestation? How have you dealt with them? Send me your ideas or leave me a comment below. If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me at Twitter. Happy gardening!

 

 

 

Pests and Diseases: Galls on Trees

I have a white oak (Quercus alba) that lives in my backyard. It’s home to birds and¬†squirrels and galls. Galls on trees are a pretty common occurrence but they can cause great concern to gardeners. Is there really cause for concern? Let’s take a look.

Galls are a growth that occurs on the leaves or branches of trees as a result of a myriad of pests. These pests can include fungi, bacteria and nematodes although the most common are insects and mites. When the insects and/or mites invade the tree, a gall is formed by the tree and the pest is protected inside. The gall also serves as a food source for the pest. For the pest, it’s pretty much a win-win; it’s protected and fed by the gall.

Galls on trees may be unsightly but there really isn’t much need for concern by the gardener. Once the gall has formed it’s going to stick around for a while. No amount of spraying will remove the galls and they don’t take a tremendous amount of energy away from the tree. Consider them an anomaly and let them be. If you are truly concerned about them, consult a Certified Arborist or your local extension agent.

For curiosity’s sake, let’s take a look at some pictures of galls.

galls on trees
Photo courtesy of www.unl.edu

 

galls on trees
Photo courtesy of www.duke.edu
galls on trees
Photo courtesy of www.foxtreeservice.com

 

Do you have any¬†experience with galls¬†on trees?¬†If you’d like to share with the Mid-Atlantic Gardening community leave me a comment below or send me an e-mail. If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me at Twitter. Happy gardening!

Pests and Diseases: Lace Bugs

If you have azaleas growing in your garden, you’ve probably had lace bugs at one point or another. Perhaps you didn’t know that lace bugs were the culprit¬†but if the top side of your azaleas leaves were stippled you did. Here’s a picture…

lace bugs
Photo courtesy of www.ufl.edu

 

Lace bugs are capable of turning your azalea’s leaves silver in appearance in no time. They breed quickly and can have several generations a year in the Mid-Atlantic gardening region, although two generations per year is the norm. As with most insects, the real damage is being done on the undersides of the leaves. It is here¬†where the lace bugs reside and also where they feed. Lace bugs have piercing-sucking mouthparts; this means that they pierce the leaf tissue and then suck out the plant juice…that’s why you end up with the stippled appearance on the surface of the leaves. If you were to flip over a leaf, you’d see this:

lace bug
Photo courtesy of www.ces.ncsu.edu

 

The black shiny blobs are the droppings of the lace bugs and the lace bugs themselves look like this:

lace bugs
Photo courtesy of www.americaninsects.net

 

So what can you do if you have lace bugs?

  1. Let’s talk about prevention first. Insects are amazing creatures that have the innate¬†ability to know when a plant is stressed. If your azaleas are in full sun, they are naturally stressed…azaleas are shade loving shrubs. If your soil is poor, add some compost each year as a topdressing to improve soil fertlity. If your soil pH is higher than 6.5, add sulfur or HollyTone¬†to lower it. By replicating an azalea’s natural environment, you can drastically lower your incidence of lace bugs.
  2. A strong blast of water to the undersides of the leaves can knock the nymphs off of the shrubs and there is a great chance that they will perish before they can make it back home. The nymphs are usually present in early to mid-May (later in colder areas) so keep a watchful eye for them.
  3. Insecticidal soap is¬†an effective control method if you aren’t able to control them with other methods. There are also plenty of nasty pesticides that can control lace bugs but you’ll have to do your own research if you choose this method.

 

It’s interesting to note that lace bugs can attack all sorts of plants: azaleas, rhododendrons, mountain laurel, sycamores and serviceberry. Don’t be discouraged if you have lace bugs on your plants…try changing the cultural conditions as noted above and then move on down the list. If you have other recommendations for treating lace bugs, please leave me a comment below or e-mail me. If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me at Twitter. Happy gardening!

 

 

 

Pests and Diseases: Cabbage Worms

Have you noticed the onslaught of white butterflies flitting aroung your garden? It seems that they’re everywhere this spring but they’re particularly noticeable around the veggie garden. There’s a good reason…they’re after our cabbage. The butterfly is the adult version of the cabbage worm.

cabbage worms
Photo courtesy of Utah State

 

But it’s not just cabbage that they’re after…they enjoy all members of the Brassica family which includes cauliflower, broccoli, collards, kales and other salad crops. The larval form is the one that really does the damage. It’s green in color and is easy to miss when quickly glancing at your plants. If you see holes in the leaves of your plants, flip over a few leaves and see if this guy is hanging around:

cabbage worms
Photo courtesy of University of Maryland

 

CONTROL OPTIONS

If you only have a few plants to monitor, hand picking and squishing is the easiest method; it also has the least amount of negative impact on the environment…unless of course you’re a cabbage worm. If you can’t bring yourself to squish them, carry a small bucket or mason jar full of soapy water and just drop them in when you see them. If you have chickens, offer the cabbage worms to your flock as a tasty, high protein snack.

Floating row covers are especially effective at deterring the moth from laying its eggs in the first place. If you grow rows of brassicas, applying floating row covers before you see the moths will reduce your population of cabbage worms to virtually zero. If you’re not familiar with them, floating row covers are comprised of lightweight woven fabric that still allows the sunlight through. They are¬†a great physical barrier to keep the butterflies away from your cabbage.

If the number of cabbage worms is too great for you to hand pick, you can¬†spray Bt to control them. Bt (Bacillus thuringiensis) is a bacteria that only affects caterpillars so you don’t need to be concerned with assaulting your beneficials like ladybugs and lacewings. Just be aware that Bt is not effective on the adults or the eggs…it only works on the caterpillar stage of the cabbage worm life cycle.

Have you seen the white butterflies flitting around your garden this year? Have you noticed any cabbage worms? If so, what methods do you use to control them? Leave me a comment below or send me an e-mail. (I’m going to stop putting my e-mail address in the posts…the spam is eating me alive!) If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me at Twitter. Happy gardening!

 

 

 

Pests and Diseases: Moles and Voles

The mole and vole population is booming here in the Mid-Atlantic gardening region…I’ve spoken to three people about control measures within the last 24 hours. There seems to be much confusion about moles and voles so let’s¬†talk about the differences between¬†the two.

MOLES

moles and voles
Photo courtesy of TermiGuard Pest Services

 

Moles have¬†a face that only a mother could love. They are beastly looking little creatures even though they are only 6″ or so long (and that’s a big one…the ones that my kitty brings home are usually in the 3″ to 4″ range). You’ll notice their large front feet that are adapted to moving a lot of soil. They dig with their front feet and then push the soil behind them¬†with their back feet. The tunnels that they leave behind in your lawn are a sure sign that trouble lies underfoot. It’s interesting to note that the tunnels that you witness aboveground are their temporary tunnels. The main source of the action lies farther underground where the moles have their permanent residence. The temporary tunnels are used for gathering food and once the mole has had a nice dinner, the tunnels aren’t usually used again by the moles. So what’s for dinner? Grubs, snails, earthworms, insects, spiders, that sort of thing. The moles are NOT eating your plant roots but that leads us to our next suspect…voles.

VOLES

moles and voles

These mousey-looking creatures are the bane of many gardeners’ existence. Generally speaking, voles are lazy and they use the mole tunnels to get to your plants’ roots. I all but gave up gardening here at my home several¬†years ago. I had beautiful, 3′ diameter hostas when I put the garden to bed in the winter. When the garden awoke from its winter slumber in spring, I had 3 leaved hostas…literally. Those little monsters ate almost all of my hostas in a single winter. The tell-tale sign of voles is a hole where your plants used to be. Not a large hole…the hole is usually 1″ or so in diameter but that’s all that it takes for them to decimate your plants. Plants aren’t the only things that voles eat but it’s the only thing that matters to gardeners. They can eat all of the fruits and nuts they want without any complaints from me…just leave my plants alone!

CONTROL OPTIONS

moles and volesHere is my best defense against moles and voles. My kitty Bilbo (about the name: we thought that her and her sister were boys so we named them Bilbo and Frodo from the Lord of the Rings. Turns out they were both girls so Bilbo is now known as Bobo and Frodo was better known as Frodie). Back to control options…You just can’t beat a good mouser for vole control. I have to thank Bobo and Frodie and Kiki for knocking out the vole population at my house.¬†The hostas that the voles didn’t eat that fateful winter owe a debt of gratitude to these girls.

Another option for controlling voles is peanut butter baited mouse traps. I know a local landscaper that caught over 100 voles in a single season using this method. A word of caution: cover the traps with a pot that your pets and birds can’t readily flip over or you’ll have another set of issues to contend with. Put the traps near the holes that you find and you’ll likely have great success.

There are all sorts of poisons that are touted to kill moles. If you choose to go this route, understand the repercussions of your pets getting hold of the dead voles. Consult your local garden center if you decide that this an option for you.

To control moles, you really need to focus on controlling their food supply. Now that doesn’t mean that you go out and kill every living insect on your property. Hopefully you know that I would never recommend something like that. But you should make an effort to control the grubs. Japanese beetle and June bug grubs seem to the creme-de-la-creme to moles. If you want to treat for grubs, spring is NOT the time to do it. As with most insects, it is much more effective to kill them when they are young. At this time of the year, the grubs are large and you just won’t get the same effect as you will if you treat them in the fall when they are smaller. I don’t give chemical recommendations but I can refer you to the Virginia Cooperative Extension Pest Management Guide which has treatments for virtually any problem you may have. In fact, download the free pdf before you read any further. You won’t be sorry. A more environmentally friendly treatment is milky spore but it takes awhile to be effective. Milky spore is a soil dwelling bacteria that kills the grubs and then reproduces in the soil. There are lots of products that contain milky spore…again consult your local garden center for product recommendations.

I hope that I’ve helped you determine if you have moles or voles and what you can do about them. I know that other Mid-Atlantic Gardening readers have suggestions for how they’ve dealt with moles and voles. Leave your comments below or e-mail me at stacey@midatlanticgardening.com. If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me at Twitter. Happy mole and vole-free gardening!

 

Pests and Diseases: Tent Caterpillars

Today’s topic is about tent caterpillars. I remember that they used to set up shop in my Grandma’s crabapple tree. When they were finished, the poor crabapple was almost strip naked of its leaves. My grandma would go out to the tree with a stick and whirl it around in the tent to get rid of the nest. Heaven help any caterpillar that she could get a hold of. It was smushed by her arthritic hands and feet; that caterpillar paid dearly for eating her crabapple’s leaves.

Had Grandma known, she could have went out to her crabapple in the fall and looked for egg masses that look like these:

tent caterpillar

Photo courtesy of Henderson State University

The adult moths lay their eggs in the fall and these masses can be clipped from the tree and disposed of. Or they can be physically removed if the masses are in areas that aren’t suitable for pruning. Once the days warm in the spring, the tiny black caterpillars emerge from the egg mass and relocate to a nearby tree crotch. Here they work on forming their tent which they return to at night. In the mornings, the caterpillars head out to the newly emerging leaves and feast for the day. Once they’ve gorged themselves, they head back to the tent to go nite-nite. This cycle continues for four to six weeks until the caterpillars are ready to strike out on their own. At this point, they travel to other trees to build the cocoon from which the adults will emerge. The adults make their grand entrance into the world in two to four weeks. The adults find their soulmate and after a brief romance, the eggs are deposited for next year. And the cycle continues…

WHAT TYPES OF TREES ARE USUALLY AFFECTED?

Tent caterpillars generally prefer cherries (wild and cultivated), crabapples, apples, peach and plums. But they can also make themselves at home in maples, oaks, poplars and ash. The good thing about tent caterpillars is that they are easy to spot.

tent caterpillar

Photo courtesy of Purdue University

CONTROL METHODS

Since the best defense is a good offense, look for the egg masses in fall if your trees are susceptible to them. If your trees are attacked one year, the chances of your tree falling victim to them in subsequent years is high. Break the cycle by removing the egg masses before the caterpillars have a chance to wreak havoc.

If you don’t catch them before they emerge from their egg masses, consider taking Grandma’s approach.¬†You can physically go after them with your stick and try to remove them by hand. Consider that the caterpillars return to their tent at night so late evening or early morning will be the best time to attack them.

I wished that chickens enjoyed them but from everything I’ve read, they don’t. Do you know of any animals that enjoy tent caterpillars as snacks? If so, please let the other Mid-Atlantic Gardening readers know. Leave me¬†a comment below or e-mail me at stacey@midatlanticgardening.com. Happy gardening!

April 17, 2012Permalink 2 Comments

Pests and Diseases: Glyphosate Damage to Trees

 

Today’s Pest and Disease post is a little different than some of the other topics that we’ve looked at such as gloomy scale or aphids. Today we are going to look at something that you may not even think of when you’re spraying weeds in your garden: glyphosate damage¬†to trees. In case you’re not up on your chemical names, glyphosate is the active ingredient in products like Roundup and RazorPro. We have been told for years that glyphosate is biodegradable and has no residual impact on the soil that it touches. More and more, people are beginning to realize that may not be the case.

glyphosate damage to trees

Photo courtesy of Ohio State University

Dr. Hannah Mathers of Ohio State University has led the research on determining if glyphosate is responsible for cankers on trees where the chemical has been applied. The cankers resemble frost cracks that can occur during cold temperature extremes. The difference is that frost cracks generally appear on the south side of the tree whereas “glyphosate cankers” can occur on any side of the tree. The long and short of her research is that glyphosate is accumulating in the phloem of the trees and causing cankers and ultimately death. The death is a slow one as microorganisms move into the canker and set up shop. Glyphosate may not be the cause of death in the end but it is what allows the microorganisms a chance to kill the tree.

So how does the glyphosate end up in the phloem of the tree? It generally occurs one of two ways: the first way is by applying the herbicide around the base of the tree and having it come into contact with the trunk. You may not be trying to spray the trunk directly but if there are weeds at the base of the tree, you may inadvertently spray the trunk. The second way is through killing the weeds that grow within the root zone of the tree. That is, after all, probably why you are spraying herbicides to begin with. When these weeds die, they exude a small amount of the chemical into the soil which can then come into contact with the roots of the trees. The roots take up the small amount of glyphosate into the xylem of the tree but as it is transported throughout the tree, it ends up being stored in the phloem. Research indicates that the glyphosate can build up in the phloem for years and continue to cause problems for the tree for a long period of time.

Dr. Hannah Mathers has found that using glyphosate products that contain a surfactant exacerbates the problem. Surfactants are added to many pesticides to allow the chemical to “stick” to the target pest. The stickiness that results also allows the glyphosate to adhere to the trees if they are inadvertently sprayed. Unfortunately, virtually all of the homeowner versions of glyphosate contain surfactants.

So what can you do to avoid glyphosate damage to trees? MULCH! While I certainly don’t advocate the practice of mulch volcanoes, a 3″-4″ layer of mulch under your trees will keep most of your weed problems at bay. For the weeds that appear, hand weeding is going to be your best option. Also, consider planting perennials under the trees. A groundcover of plumbago (Ceratostigma plumbaginoides) will thrive in sun or shade and will form a dense mat that is almost impenetrable to weeds. If you don’t have to have the perfectly manicured garden, consider planting a nitrogen fixing plant under your trees so that the trees have a free source of nitrogen. Examples include members of the legume family such as peas and beans, alfalfa and clover.

I hope that you’ve gleaned a bit of useful information from today’s post. Take a look around your yard and other landscapes to see if you spot any of the “glyphosate cankers”. Let me know what you find by leaving me a comment below or sending me an e-mail at stacey@midatlanticgardening.com. Happy gardening!

March 13, 2012Permalink 2 Comments