Turns out a dead Japanese beetle IS a good Japanese beetle!

Mike McGrath explains when to plant a new lawn, why you need to keep your greenhouse cool, the best way to eradicate Fusarium wilt, how to feed your garden, tricks to protect your roses from viruses, and what to do with dead Japanese beetles.

Questions of the Week:

“The instructions on commercial Japanese beetle traps emphasize that you have to change the bag often or the smell of the dead beetles will repel the living ones. I decided to try and use that to my advantage. When a trap bag got full, I let the beetles in it die, punched some holes in the bag, pounded it a bit, and hung it on the cherry tree they were destroying. Complete success; no beetles attacking the tree. Now I’m going to trap some more and hang their corpses on my rose bushes!”

— Carol in Princeton, New Jersey

Learn how to keep Japanese beetles away »

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  Photo by Flickr user Sadik Kassam

Highlights from show for August 2, 2014:

When to plant a new lawn

Mark in Traverse City, Michigan is just thawing out from winter and lives on a small lake that is in excellent condition. He wants to plant some new grass, but wants to protect the health of the lake. The area is sloped and he wants to raise and level it off and plant some grass. Mike reminds him that grass never needed chemical inputs, so it should be no problem to keep this organic. “A true cool season grass is going to be relatively self sustaining.” If you cut it correctly you will never have to feed it. Mike says the choice of grass is going to be critical so he recommends a turf type tall fescue. He reminds Mark that he should get a named variety so he can over-seed bare spots with the exact seed. The other major point is to get the seed down by August 15th.

Keep your greenhouse cool

Sarah in the Mount Airy neighborhood of Philadelphia has a hobby greenhouse with lots of green growth. However, nothing is fruiting. Especially the cucumbers, which are huge, but their flowers are not turning into fruit. Mike says the only reason the plants aren’t dead is that Sarah has proper venting and fans. Greenhouses are meant to concentrate heat. “You can start all number of seeds and a great place to get early growth.” Mike says greenhouses can become torture chambers for plants in the summer and the pollen just fry’s. He recommends using shade cloth to cool it. In terms of getting the flowers to pollinate he suggests that Sarah do it by hand. In the future he says to just realize that the green house will be your best friend in the spring and in the fall. Over summer most people just close it up and let it bake to get rid of disease.

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  Photo by Flickr user Nick Harris

Fusarium wilt

Kristi is at Penn State in State College, PA and is working on her dissertation research, which focuses on Fusarium wilt. She is hoping that You Bet You Garden listeners will contact her to let her take soil samples of tomatoes and peas. Fusarium occurs more often in the South, so our southern listeners should take note. The fungus will produce resistant spores that can last for a long time and there is really no way to combat this. Herbicides don’t work and resistant varieties don’t always work either. Kristi is in Florida right now. August 8th – 15th she’ll be driving through Ohio, Indiana, Illinois, and Wisconsin to Minnesota and back. August 18th Kristi is heading to New England (NY, CT and MA) Kristi is hoping to hit the west coast after September 1st. If you’ve been growing tomatoes or peas send her an email and maybe she can take a sample of your soil. Your plants do not have to be diseased for her to sample the soil.

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  Fusarium wilt.

Harry Lauder’s Walking Stick

Ron in spokane washington has a contorted filbert tree and he has no clue on how to trim or care for this interesting plant. Mike informs Ron that the most common name is Harry Lauder’s Walking Stick and he tells Ron that he won’t find it under the other name. He is one of a group of crazed fanatics for this unique plant. Ron says it is so full you really can’t see the contortions of the branches, so he wants to trim this back safely. The winter time is your time to trim this, says Mike. That’s when you can look at the bones of it. “In the dead of winter in January that’s when you can go out and look at this tree and say if I remove this branch here and here then there is going to be some space open in the center.”

How to feed your garden

Alan has a garden located in Cherry Hill, NJ where he has a planter box made of paver material that is about 20 feet by 3 feet and every year he plants veggies there. This year he decided to try Zucchini and the plants came up, but all the flowers are male so he thinks he needs females to get fruit. He admits he fed them miracle gro so Mike says that is 90% of the problem. “If the plants are stressed, too much rain, not enough sun or chemical fertilizer than the plants will continue to produce male flowers and you won’t get very much zucchini.” Mike says a two inch layer of compost is all the gentle feeding they need.

Protecting your roses from viruses

Worth in Oklahoma City, OK has a pink climbing rose that is well over 50 years old and for the first time the foliage and flowers started dying and now it just looks like a pile of dead thorns. There is a rose virus going around that causes distorted growth and Worth admits he did see some of the signs of this virus. The good news Mike says is it is not Wroth’s fault. Worth says there is still one green cane left. Mike recommends continuing to prune off the dead stuff and keep it well watered. “First I want you to mulch it with compost and put a good two inches of that around it.” Then Mike says to let a hose drip at the base of the plant to really saturate it. That green cane is Worth’s hope for next year.

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  Photo by Flickr user maorlando

Troubled tomatoes

Matt near Doylestown, Pa has tomatoes that turned yellow and brown and the leaves and branches started falling off from the bottom up. Matt says they have been in the same place every year. Mike tells Matt that he has one of the two soil born wilts Verticilium or Fusarium wilt. “These are diseases that build up in the soil around the roots of susceptible plants. Tomatoes are the most effected.” Mike recommends taking off all the yellow leaves and not planting in the same place next year.