Battling Japanese Beetles

Soapy water in a coffee can early morning is the best time to catch Japanese beetles. (Photo by Charlotte Ekker Wiggins)

“Hi Charlotte, what are nematodes and where do I get them? I have heard that suicide beetles kill Japanese beetles also, saw two yesterday on a butterfly bush….” — Elaine

Battling Japanese Beetles

Hi Elaine,

Nematodes are microscopic parasitic roundworms that live in soil and destroy Japanese beetle grubs before they start the next growing cycle. You can find nematodes for sale at most home and garden centers. You are looking for the species that specifically targets Japanese beetles.

Your best bet for battling Japanese beetles is to remove them early morning by knocking them into a pan of water with drops of Dawn dishwashing liquid. They tend not to move as fast when the temperature is cooler.

Japanese beetles are lovely irridescent green invasive bugs. (Photo by Charlotte Ekker Wiggins)

Japanese beetles tend to show up in USDA Hardiness Zone 5 around early July. Their main purpose is to procreate during the 4-6 weeks they are in gardens consuming most edible plants from fruit trees to grape vines, Rose of Sharon to edible wildflowers.

Japanese beetles damage leaves but don’t kill plants. (Photo by Charlotte Ekker Wiggins)

If there is one consolation about these invasive bugs, their hearty appetite does not kill the plants, just disfigures them.

And most recently, assassin bugs have been noted as catching and eating Japanese beetles.

Charlotte

Dead Mums Good?

Three of my “dead” mums on one of my flower beds. (Photo by Charlotte Ekker Wiggins)

“…what’s the big deal about mums? I do like them. It’s trouble to have to water them through winter. Dead mums look bad. What do they do in garden?” — Andy

Dead Mums Good?

Hi Andy, oh, my, where to start. They are practical, they are easy to grow, they are pretty AND they are long-lasting. And there’s a good reason why you should appreciate them when the top is dead.

First, there’s no getting around that dead chrysanthemums (also called mums) in a garden are not pretty. Unless they are covered in snow, and then they are quite sweet-looking, little mounds of white scattered throughout my hillside. The value of the dead chrysanthemums is that they are protecting new growth developing underneath, at the heart of the plant.

If you have some in your garden, go out in daylight and take a peek. These three mums in the photo were planted last fall and photographed January 9, 2020. I have been ensuring their roots were hydrated by periodically watering them, which also gave me an excuse to walk through my garden and see how things were doing.

If we had rain, or snow, I didn’t bother because nature was taking care of watering duties. In general, plants need an inch of rain a week.

Natural Bug Deterrent

My goal is to have mums scattered throughout my garden. Mums are a natural bug deterrent. Most of the “safe” garden insecticides you find currently on the market are made with pyrethrins, which is essentially essence of mums.

By having mums scattered around, you are using them for bug deterrence as well as enjoying some of the longest lasting fall flowers, when most of the color comes from deciduous tree leaves changing color.

And as an added benefit, mums are also one of the longest lasting cut flowers you can find in any garden. That’s why you will find florists using mums in flower bouquets.

Checking Mums for Growth

So what are you looking for when you peek through the dead mums? As you approach, it may seem like there is no sign of life. Be patient, and gentle. Look into the mum at the bottom of the center.

This is the first mum, bottom right in the photo. See the green growth in the center?

A mum planted last fall is showing new growth dead center. (Photo by Charlotte Ekker Wiggins)

What still amazes me is how a little patch of green in winter can turn into a full blooming plant by the next summer.

If you were to dig up and separate this little patch of green, you will find several plants growing together.

Here is the second mum, mid level on the left of my hill. See anything?

New growth is farther along in this mum planted last fall. (Photo by Charlotte Ekker Wiggins)

This one also has new growth a little farther along than the first one photographed. If I had to guess, this will have a good half dozen plants started if they all make it until spring.

And no, I won’t cut off the dead mums from last year. Those dead stems are protecting the new growth from cold and wind, which can kill them.

One more mum to check, the top left one.

Top left mum is also showing new growth at the base. (Photo by Charlotte Ekker Wiggins)

This mum developed new growth later than the middle one, maybe about the same time as the bottom one. I thought I had planted all three about the same time but maybe not.

All three are showing good new growth so far so I will keep an eye on them as winter unfolds, making sure their roots are hydrated and growth protected with shredded leaves and wood mulch. The mulch will help keep the soil from heaving and thawing, which stresses out young plant roots.

Come spring, I will start the vigil of pinching growth when it reaches about 4 inches. I just tuck the extra growth in the ground next to the mother plant and let that piece root on its own.

By fall, this is what I should have again along my garden paths, mums in bloom.

Some of the yellow mums in bloom last fall in my garden. (Photo by Charlotte Ekker Wiggins)

Mums are definitely among my top 10 must have garden plants for any garden. Once established, they take very little effort to grow and they are helpful as well as pretty and long-lasting. My kind of flower!

Charlotte

Mums Dead or Alive

Mums are favorite fall flowers often tossed after they bloom. With a little care, they can get established. (Photo by Charlotte Ekker Wiggins)

“…you said something at the last lecture about Mums being natural bug deterrents. I planted several but now I can’t tell if they are dead or alive. What’s the secret?” — Lisa

Mums Dead or Alive

Hi Lisa, if you couldn’t tell, Mums are one of my favorite all time flowers. In addition to being long-lasting as cut flowers, they are a great bug deterrent and so easy to grow.

it helps to understand a little about how Mums grow. Mums, or chrysanthemums for short, are pinched during spring growth to make them bush out into the round shape we are used to seeing, and buying, in fall. I have several in my garden I miss pinching so I know how long and leggy they can grow. I don’t mind, though, because those are easier to add to a vase to bring inside and enjoy by themselves or with other cut flowers.

The round, bushy shape makes it hard to see new growth, which takes place at the base of the plant. Growth can also occur when you sneak a branch into soil and roots develop at the growing nodes, which are the bumps you feel along the plant stem.

So take a look at this Mum and tell me if you think it’s dead or alive:

Red mum covered in snow in my Missouri hillside garden. (Photo by Charlotte Ekker Wiggins)

It looks dead, doesn’t it. And yes, it was cold and windy when I took this picture to show you looking at the plant is not how you determine if it’s surviving. Gently push the dead stems apart and look at the base. If the Mum is still alive, you should see tiny green growth:

New growth at the base of the dead-looking Mum. (Photo by Charlotte Ekker Wiggins)

Be careful when you move the dead branches, it’s easy to break them. If it’s too cold to move them, peer through the top and see if you spot any green at the bottom.

I’ve been known to sneak peeks at the base of my new Mums through winter as I water them. There is something magical about seeing the dead top and then spy new growth underneath at the root. Leaving the dead branches also provides the new shoots protection from winter elements.

Why bother? Besides being pretty and easy to grow, Mums are bug deterrents. Many of the “organic” and “safe” insect sprays these days are made with pyrethrins, basically essence of Mums. By adding a few Mums throughout your garden you can help deter insects and still enjoy pretty fall flowers.

Yellow fall Mums join a sprig of red Peruvian lilies, both long-lasting cut flowers. (Photo by Charlotte Ekker Wiggins)

Just remember to water them a couple of times a month through winter to help the roots get established.

if you want that fall round shape, pinch them through spring growing season once very 4 inches. When I pinch mine, I just stick the cut off portion back in the soil to grow new roots. Or move that bunch of pinched branches to another spot and push them into the ground for a new mum. It may take a couple of years in my rough hillside soil but they do grow quite nicely.

We are having our first snow of the season today. Time to start dreaming about next year’s garden!

Charlotte

Systemic Insecticide & Japanese Beetles

A Japanese beetle on a wild grape leaf at Bluebird Gardens.

"My knockout roses are being eaten by the Japanese beetles.  Why doesn't the rose food with systemic insecticide bother the beetles?  Thanks."  -- Lynn

Hi Lynn,

For systemic insecticides to be strong enough to kill Japanese beetles, they would kill the roses first.

Have you tried hand-picking the beetles? Do it early morning. Sneak a container with soapy water under the leaves with the bugs and the bugs will fall into your container.  If you get them early enough, they won't leave a trace pheromone for other beetles to follow.

You can also try wrapping your roses in cheesecloth or fruit tree netting.

Let me now what ends up working best for you. The good news is that they only live for about six weeks. Good luck!

Charlotte