6 pests & weeds to watch out for during spring in WNY

pest and weeds in spring
Pests and weeds that you have to watch out for this spring include, from left, red lily leaf beetle, crabgrass, lesser celandine, ticks and creeping Charlie. Photos provided by Gordon Ballard; R Dyer, Bugwood.org; Connie Oswald Stofko; Jim Occi, BugPics, Bugwood.org; Connie Oswald Stofko

 

by Connie Oswald Stofko

Now is the time that certain troublesome insects and weeds can show up in your garden, and now is the time to take action.

Today we’ll talk about six insects and weeds to watch out for in spring: red lily leaf beetle, ticks, mosquitoes, lesser celandine, creeping Charlie and crabgrass.

Red lily leaf beetle

Calls have started coming in from gardeners who have spotted the red lily leaf beetle, so it’s time to look closely for it in your garden, said John Farfaglia, extension educator with Cornell Cooperative Extension in Niagara County.

red lily leaf beetles mating
The red lily leaf beetle is spreading in Western New York, causing damage to lilies and fritillaria. Photo courtesy Gordon Ballard

“People are still seeing the red lily leaf beetle for the first time,” Farfaglia said. “If you have lilies, the likelihood is that you’re going to see it. By now, I’m a little surprised if people say they don’t have it.”

The red lily leaf beetle, which we first talked about in 2015, is a fairly new invasive species in Western New York. It can cause extensive damage to lilies and a spring bulb plant called fritillaria. The pests aren’t a problem for daylilies, which aren’t true lilies.

Updates on the red lily leaf beetle

Please report on cedar mulch  

Last fall, Farfaglia told us that a gardener noticed that the red lily leaf beetle didn’t seem to bother the lilies in a bed covered with cedar mulch.

Did you try cedar mulch on your beds around your lilies? If so, Farfaglia wants to know if it worked for you. Just as important, he wants to know if it didn’t work. You can contact Farfaglia directly or leave a comment below. Thank you for being a citizen scientist!

Try coffee grounds

There have been some firsthand accounts that say placing coffee grounds around lilies could discourage the red lily leaf beetle. There isn’t any scientific evidence yet, Farfaglia said, but you could try it. Be prepared to let him know whether or not it worked.

Using wasps to battle red lily leaf beetle

A trial using certain wasps to reduce the numbers of red lily leaf beetles in Western New York is under way, but it may be a number of years before we hear whether it is having a significant effect, he said.

“I would like to think it will have a reduction in the population of red lily leaf beetles,” Farfaglia said. “My understanding is that it has at earlier sites” where the wasps have been released.

Watch to see which varieties of lily are least susceptible

While no lily is immune to damage from the red lily leaf beetle, Farfaglia said he thinks some varieties of lily will prove to be less attractive to the pest. In the future, we may be able to recommend certain varieties that are better than others.

Again, if you notice a difference among your varieties of lilies, please let Farfaglia know.

What to do now about the red lily leaf beetle

Now is the time to look for the red lily leaf beetle.

If you had a problem last year, you can start a preventive program applying a pesticide called neem oil now, at the beginning of May. Or you can monitor your plants and start treating them when you see the insects.

Farfaglia recommends neem oil for use by home gardeners because it is less toxic than other pesticides listed on the Cornell factsheet, and people have had reasonably good luck with it.

You can also try picking the adults off, but that’s difficult because they’re fast. The larvae are also difficult to handpick, and they’re gross because they cover themselves in their own feces to fend off predators. See the life cycles of the red lily leaf beetle here.

“As disgusting as it is, handpicking really does help,” Farfaglia said.

If you don’t want to handpick the pests or use insecticide, your final choice is to plant something other than lilies and fritillaria.

 

Ticks & mosquitoes

Ticks and mosquitoes are troublesome because they can cause disease in humans– and the number of diseases has increased.

blacklegged ticks, adults and nymphs
Blacklegged ticks are tiny. Here they’re compared to the head of a straight pin. Adults are on the top and nymphs are at the bottom. Photo courtesy Jim Occi, BugPics, Bugwood.org

The Centers for Disease Control (CDC) recently released a report that said nine new germs spread by mosquitoes and ticks were discovered or introduced into the United States from 2004 through 2016.

“Zika, West Nile, Lyme, and chikungunya—a growing list of diseases caused by the bite of an infected mosquito, tick, or flea—have confronted the U.S. in recent years, making a lot of people sick,” said CDC Director Robert R. Redfield, M.D. “And we don’t know what will threaten Americans next.

“Our nation’s first lines of defense are state and local health departments and vector control organizations, and we must continue to enhance our investment in their ability to fight against these diseases.”

Ticks are active now, Farfaglia said. Mosquitoes need warmer weather, but they will hatch around the end of May.

As gardeners, what should we be doing?

Learn how to protect your yard from ticks in this article we posted last year.

You can also take steps in your yard to control mosquitoes. Mosquitoes lay eggs near water, so once a week, look for items that hold water, such as tires, buckets, planters, toys, pools, birdbaths, flowerpots or trash containers. Turn them over so they don’t collect water, or empty them and scrub them, or get rid of them. See more tips for protecting yourself from mosquitoes here.

 

Lesser celandine

I see beautiful fields of lesser celandine when I stroll through my neighborhood. Unfortunately, those pretty little flowers will take over your lawn. Worse, they can end up in wild spaces and out-compete native plants.

lesser celandine in Amherst NY
Lesser celandine is a pretty little plant, but it can destroy your lawn and invade wild spaces. Photo by Connie Oswald Stofko

“At this time of year, it’s so obvious that the plants are here,” Farfaglia said, “but they go dormant in the summer and people forget about them.”

Just because you don’t see them in the summer, that doesn’t mean that the lesser celandine has gone away. It has actually spread. Next spring you’ll have even more. One reader said it covered 7/8 of her yard.

Don’t let it get that far! If you have just a few patches, dig it up now. Lesser celandine is so troublesome because you have to kill the roots, and that is difficult, said Carol Ann Harlos, Master Gardener, garden writer and speaker. It has tiny tubers. If you try to dig it up and miss a tuber or even break a tuber, the piece left in the ground can generate a new plant, she explained.

The spread of lesser celandine seems to follow streams and creeks, Farfaglia added. The plant is also spread through compost and topsoil, so be careful not to get any of the tubers in your home compost. And don’t put any tubers you’ve dug up in with your weeds and brush that you put out for your town to compost, either.

To kill the tubers, you can also use the herbicide Roundup, Harlos told us last year.

“Spray Roundup on the leaves and it goes into the roots,” she said.

Another idea, which may or may not work, is solarization. The idea is to cook the roots by covering an area with black plastic. Keep the plastic there for several months. See the previous article for a few more details.

Please don’t just ignore lesser celandine. Remember, it’s not just a problem for your yard. It’s a problem that is spreading to your neighbors’ yards and to wild areas.

Creeping Charlie

This is a weed that I struggle with. It gets everywhere!

creeping Charlie in Amherst NY
Creeping Charlie stretches from a lawn over a stepping stone. Photo by Connie Oswald Stofko

The Master Gardeners of Erie County published a great article on creeping Charlie by Lyn Chimera. The key to success with this weed, she said, is to dig it up as soon as it appears.

If an herbicide is required, now is the time to apply it. During the heat of the summer, plants are not growing as fast and are not as susceptible to the effect of herbicides, she said. Studies have shown that spring and fall are the best times to apply.

Keeping your lawn healthy can also help keep creeping charlie at bay. And if you can live with creeping Charlie in your lawn, just let it be. It will remain green in the summer. Oh, and you can eat it!

See the Master Gardeners’ article for more information.

 

Crabgrass

People have been calling with lawn questions, and one thing they ask about is crabgrass, said Farfaglia of Cornell Cooperative Extension in Niagara County.

crabgrass
If you need to apply preventive treatments for crabgrass, now is the time to do it. Photo courtesy R Dyer, Bugwood.org

If you need to apply preventive treatments for crabgrass, now is the time of year to do it, he said. Rule of thumb: Apply preventive crabgrass treatments when forsythia is in bloom.

But keep in mind that if you are reseeding or patching your lawn, crabgrass control could interfere with the sprouting of grass seed.

If your lawn is in good condition and fairly dense, crabgrass shouldn’t be a problem, Farfaglia noted. In that case, you don’t need to use a preventive treatment.

Get more information on caring for your lawn at this Cornell University site.

17 Comments on “6 pests & weeds to watch out for during spring in WNY

  1. Unfortunately the black mulch I piled sky high had no effect on the evil red lily beetle! I go out and squash them with needle nose pilers-yes I HATE them

  2. Thanks for the nudge! I made a fresh batch of neem oil spray and decided to spray the 2 dozen lily plants in my small city of Buffalo garden as a preventative. Wrong! Those darn red beetles are already emergent! I squashed three and thoroughly sprayed the emerging plants and surrounding soil.
    I was vigilant last year, hand picking every day and spraying every third or fourth day and my lilies survived, with only a few looking ragged. I’ll try the coffee grounds and let you know if they work.
    If not for this newsletter I probably wouldn’t have sprayed until this weekend, so thanks to you I have already started my beetle battle.

  3. I have found them 1 wk ago at my daughters in tonawanda
    Today in north Java
    I use dr jacks dead bug spray and powder with great effect

  4. I haven’t commented recently, you website is great for western New York. Always on point! Thanks for your excellent effort to help all gardeners.
    Rich – Lancaster Garden Walk

  5. I love this newsletter, but I’m terribly disappointed to see Roundup being mentioned for weed control. With all the information we have about how toxic this product is, I had hoped more gardeners were being responsible and avoiding it like the plague that it is.

  6. I found the red lily beetle this year, so dug out my dawn dish soap. Just a few drops of dawn in a spray bottle with water seems to help. I don’t see as many and new leaves are showing no holes. Time will tell.

  7. Catherine, thanks so much for your comment. When it comes to using any kind of pesticide, you have to weigh the pros and cons. You don’t want to use presticides routinely, as Paul Tukey said in an article in August. You can certainly try to dig up all the tubers of lesser celandine, and that is definitely the first route you should take. The problem is that some people just give up and let the lesser celandine spread. If you have pesky weeds like creeping Charlie in your lawn, just ignoring it is definitely an option. The problem with lesser celandine is that it can easily spread to wild areas and out-compete native plants. Using Roundup (carefully, according to the directions, not routinely) to eliminate lesser celandine may be better for the environment than simply letting this invasive plant spread. But yes, please try digging it up first.

  8. Anyone know what to do with daylily leaves that appear chewed and mushy and they come out of the ground? It is obviously some kind of insect that lives in the ground.

  9. Elaine – what you are seeing is a actually type of foliage. It will right itself as the season progresses, but looks bad in early spring. For more information, look for “evergreen daylily foliage”.

  10. Thanks, Kathy, but I’m not totally convinced that this is just a problem of poorly chosen plants. On some of the plants, it looks like there are holes up and down along the leaf edges. Yesterday I moved one of these plants to a different area and found inch long super skinny white worms in the soil nearby. However, I don’t know if they are the cause of the problem either, as I don’t know what these worms are.

  11. Bonnie B. Re; red lily leaf beetle. Over a week ago when the lilies first sprouted from the ground (maybe 1″ tall) I was out there smothering plant and ground with powdered Sevin. It may not be the proper item to use but it works. The plants are 3-4″ tall now and after it rains tomorrow I will give the plants another dose. I have lilies in 9 areas of my yard and so far I have only seen 2 beetles.

  12. I also found red lily leaf beetle all over my Chinese lanterns. Had to get rid of them. And ugh, those larvae are disgusting!

  13. I tried the coffee grounds. No luck, so I’ve been handpicking…probably over a hundred so far. And lots of mating pairs…at least they’re going out happy!

  14. FYI had red lily leaf beetle for 2 seasons, used Neem oil & dish soap and sprayed plants and soil for both seasons, this year no sign of the pest so far. Hoping that I winning the battle.
    Rich Groblewski

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