What's Eating My Garden??!!
Question. I gave up trying to have an in-ground garden because of Bambi and his 'stag parties' and now grow in large containers on my patio. But something is eating holes in the leaves of my peppers, basil and squash. No critters are visible—and I'm trying to be pesticide free. HELP!
- ----Cheri in Fairfax, VA
"But I haven't seen any slugs," yelled Cheri in reply to our emailed suggestion, "and I thought they munched on roots, not leaves." Nope. In your part of the country (just outside of Washington, DC) the only root munchers of any consequence are voles, small mammals with enormous appetites and even larger reproductive capacities whose numbers have exploded with the foolish trend of so-called "decorative mulching" with shredded wood and bark. When roots are devoured—especially in landscapes drenched in this wood waste masquerading as mulch—think voles.
And the only people who SEE slugs doing their dirty work are prowling around in the middle of the night (or on really rainy days). The fact that slugs are out when we're generally not often leads to an assumption that some kind of crafty invisible insect is to blame.
But British researchers proved slug guilt in a brilliant study published in the Journal of Ecology back in 1992. They saturated one field with insecticide, and treated a similar field with 'molluscicide', a twenty-dollar word for slug poison. (In their case, it was a pretty nasty chemical; today there's a wonderful non-toxic slug control option whose active ingredient is iron phosphate.) The insect-protected field suffered greatly, while the one adorned with slug killers thrived—despite, the researchers note, it being a dry year in an area not known for slug problems, and a lot of pest insects clearly visible.
It gets better. The researchers never saw live slugs—even after looking for the nocturnal nemeses at night. But they DID find lots of dead ones after each slug treatment. It's easy to replicate their experiment; just place little margarine tubs filled with fresh beer—NOT stale—around the plants that are under attack, after the sun goes down in the evening (NOT in the morning or heat of the day—the beer will go stale and repel the slimers). If slugs are to blame, the containers will be filled with dead drunken evidence in the morning. Then read our previous Question of the Week on slug control and give 'em heck!
Question. This season, I took the time to really plan my vegetable garden. I started the plants from seed and installed a drip irrigation system (of course, its been raining constantly now after two years of drought). But on a recent walk through my garden, I noticed that something had been munching on my corn, my eggplant leaves look almost translucent, my sunflowers are gone, the tops of my marigolds are eaten away, my string bean plants are disappearing, and all the new growth is missing from one of my young blueberry bushes. HELP! We put a layer of straw down to prevent weeds; could that be the cause of the problem? Thanks,
- ---Beth in Asheville, NC
When the tops of taller plants like corn and sunflowers suddenly disappear, think deer—same for the blueberry damage, and maybe the string beans. And because deer are most active in the very early morning, they often go as unseen as slugs. Luckily the damage—the tops of plants cleanly sawed off—is very distinctive. I aim a motion-activated sprinkler at the parts of my garden with low-to-the-ground plantings they enjoy, like bush beans, and place old tomato cages over my potato plants, another favorite of theirs. I also use deer repellant to protect the odd plant outside my garden proper; and I'm looking seriously at small electric fencing systems. You'll find more deer-deterring advice in a previous Question of the Week we'll link up to.
Damage to marigolds, string beans and other low to the ground crops (I'm presuming you have bush beans as opposed to pole beans) could also be deer—or rabbits or slugs. Rabbits eat entire sections of plants, while slugs tend to consume only leaves and fruits, leaving behind depressing little tree-like stems. And you generally see rabbits, as they do their dirty work during the day (groundhogs are even more obvious about their presence).
If all the eating is down low, and you've eliminated slugs (although your combination of a straw mulch, irrigation and lots of rain makes them a prime suspect here), get over any Disney delusions and install a small rabbit fence; it's very effective. You'll find other deterrents in our rabbit Question of the Week (you noticing a pattern here?).
And finally, 'translucent" eggplant leaves generally indicates flea beetles, devastating insect pests that turn plant leaves almost transparent by chewing hundreds of little shotgun shell-like holes into them. What's that? You'll look at our previous Question of the Week on flea beetles? What a great idea!