Tips for a healthy summer garden
WASHINGTON - Gail in Kensington was one of many listeners who emailed after hearing me discuss mosquito control on the air last week, and every listener asked about the same thing: the non-toxic backyard ‘foggers' made from garlic oil that keep mosquitoes—and gnats and ticks—away from your outdoor space for a solid month.
The original garlic oil product is called Mosquito Barrier. It's a concentrate that you dilute with water and use in your own sprayer. It comes in several sizes and gets rave reviews from many communities that use it instead of toxic sprays.
Another popular brand is mosquito repellent from St. Gabriel's Labs. It's a ‘ready to use' product that comes packaged in its own hose-end sprayer. The company also sells the milky spore powder that you use in late summer to kill beetle grubs in your lawn.
You'll find these and other brands for sale online and at larger independent garden centers. Make sure to look for outdoor mosquito replants with ‘garlic oil' as the active ingredient.
Does ‘Rabbit Scram' Make Rabbits Scram?
Karen in Leesburg writes:
"I recently planted new flowers in my garden and the rabbits are eating them. Does Rabbit Scram work? Is there any natural repellent I can use to keep them away?"
"Rabbit Scram" is a combination of blood meal, meat meal, white pepper, garlic, and cloves in granular form. In my experience, you can't depend on things you simply spread around the garden to keep herbivores (such as rabbits) away.
Now, since you're growing flowers, you can use a spray-on repellent. Sprays are much more effective than granular products. You can use a spray designed for rabbits or a deer repellent made from putrescent egg solids - those things repel pretty much any herbivore.
But spray or shake, you have to keep buying and reapplying repellents, and that can quickly get expensive. Instead, consider once and done fencing. Because the rabbits endemic to our area don't dig, you can easily keep them out of growing areas with a fence that's a mere one foot high and sunk a few inches in the ground.
Mysterious Damage? Suspect Slugs!
Mareta in Arlington writes:
"Help! My impatiens are being cut off at ground level. I did some research and have concluded that I have cutworms for the first time ever. Any suggestions on how I can rid myself of these things?"
Cutworms are traditionally an early season pest. I've never heard of them going after impatiens—so I asked Mareta if she had actually seen any of those nasty little caterpillars.
"No, but now the pest is chewing holes in my hostas!"
Aha! Holes in hostas equals slugs, guaranteed. Slugs are also a prime suspect when other shade lovers—like impatiens—are attacked.
Put out little saucers of fresh beer at dusk near the attacked plants to verify the criminal. Check them in the morning and you should see lots of dead, drunken slugs. (Note: Don't use stale beer; only fresh. And don't put them out during the day—the beer would go bad and repel the slugs.)
Then spread a slug bait - whose active ingredient is iron phosphate - around the plants to get rid of them. These non-toxic slug killers are packaged under a variety of brand names, often fun ones like "Sluggo" and "Escar-Go!" These baits are great - totally harmless to people, pets and the environment, but death to slugs.
Slime Mold? Wood Mulch!
Jane in Rockville writes:
"This morning, I discovered that the mulch under a newly planted rose bush was covered with a bright yellow slime mold. I looked on the internet and found ideas ranging from applying vinegar to just leaving it alone. What do you recommend?"
I recommend that you get rid of the trashy wood mulch your slime mold is growing on, Jane! You didn't need to tell me that your rose was mulched with wood or shredded bark—the slime mold did.
Get rid of that trash mulch ASAP. Although foolishly popular, these wood mulches breed all sorts of nuisance molds and plant diseases, like the dreaded black spot. Your roses will do much better with a mulch of black yard waste compost (which prevents diseases instead of incubating them).
Yellow Leaves on Tomatoes? Don't Spray!
Sal in Prince William County writes:
For the past two years I've been having problems with my tomatoes. The leaves turn yellow, wilt and start to die from the bottom up. An article in the Washington Post recommended using Daconil Fungicide. I used it, but the plants continued to turn yellow and eventually died. This year, I began the Daconil treatment right away. However, the plants are still turning yellow and wilting."