Monday, June 15, 2009

HELP! What's Eating My Basil?

This year I was psyched to have planted a nice large, healthy basil plant directly IN the garden (as opposed to an herb planter as I've done other years.) Given that the plant started out so big and healthy, and it would have all that great garden soil to grow in I was expecting huge volumes of basil this year. YUM! I love the stuff!

But the past week or so I've noticed an alarming fact. My basil seems to have about half the leaves it had originally. HALF. Really. Many of them are just completely eaten away. I can tell it's an insect of some sort because it started with little holes in the leaves. So, after googling this problem (Yes, I literally searched for "what's eating my basil") I have come to the conclusion that it is probably slugs. I have seen enough of 'em in our yard to know we have a ton. Note to slugs: The war is officially on! That's MY basil!!!

So I found the best collection of tips on ridding your plans of slugs at Check out this list if you think you're having some issues with these buggers too. And let me know how these work if you try 'em! For starters, this city girl is gonna head out there with some beer traps to confirm who my pests are, and also take the coffee approach. Now here are those tips courtesy of

1) Beer. Yes, it really does work. It’s also the best non-personal way to confirm that overnight damage is due to the slimy beasts. Just don’t use the often-cited “stale beer”, which slugs like about as much as you and I do. Place commercial traps or old margarine tubs on top of the soil close to the damaged plants, wait until dusk and then fill them with the cheapest—but freshest—beer you can find. The next morning, they should be filled with dead drunken slugs. Dump this defeated debris nearby (where it will attract their cannibalistic pals) and repeat every evening.

2) Coffee. New research has found caffeine to be very effective at dispatching slugs. Save your dregs and spray them full strength directly on the beasts in the evening. Surround plants under attack with a mulch of used coffee grounds to deter slugs and feed the plants.

3) Iron phosphate. Turns out that iron is very bad for a slug’s digestion. Like deadly bad. So a new generation of products with brand names like “Sluggo” and “Escar-Go!” wrap iron in a slug-attracting bait. You simply scatter the pellets around plants in peril to wipe out the pests without poisons. (And a little extra iron is good for your garden soil.)

4) Copper. Slugs get shocked when they touch this shiny metal. You can buy ready-made copper plant guards or just adorn your raised bed frames with copper flashing. Hot-glue rings of pennies around the tops of your containers. Drop captured slugs into a jar of pennies and watch ‘em spark!

5) Diatomaceous earth. Available at garden centers, ‘DE’ is the mined fossilized remains of dinosaur-era, sea-going creatures called diatoms. It looks like white flour, but is incredibly sharp on a microscopic level, dehydrating slugs on contact. Surround plants under attack with protective rings of DE (be sure to wear a dust mask); freshen them up if they get wet.

6) Boards. Lay some old planks between your garden beds. The vampiric slugs will crawl underneath to hide from the sun. Come morning, lift the boards and scrape the slugs into a bucket with a flat piece of metal. Then do with them what you will. Hey—got any pennies?

7) Human hair. Surround your plants with a protective barrier of hair. The slugs will get all tangled up in it and strangle (hey—it was them or the hostas!); and the hair will eventually add plant-feeding nitrogen to the soil.

8) Citrus. Leave lemon, orange and grapefruit rinds out overnight near slug prone plants, and then collect and trash them—covered with slugs—first thing the next morning. Old lettuce leaves work well too.

9) Vinegar. A spray bottle filled with plain white vinegar is a great cure for slugs that aren’t on plants. An extremely effective mollusk dissolver, vinegar is also an herbicide—so don’t spritz the salvia.

10) Toads. Avoid all pesticides, provide water low to the ground and a damp shady pot for them to hide during the heat of the day, and these wonderful nocturnal predators will eat lots of slugs for you.

11) Rove beetles. These big black bugs don’t bother plants, but do eat LOTS of slugs and their eggs. So don’t hurt them!

12) Lightning bugs. The larval form of these summertime entertainers, the fascinating “glowworm,” eats slugs and their eggs. To encourage adults to breed nearby, turn off outdoor lights at night, allow a small area of your garden to stay moist and a little weedy, and don’t use pesticides.

13) Ducks! Just turn a few loose in the garden—these feathered friends (and natural fertilizer providers) are among nature’s FINEST slug-eaters! And all together now: “We can always use the eggs”. Thank you.


  1. call your local cooperative extension service they should have an IPM person dedicated to finding any bug problems you have...and it's free :)

  2. You can also use crushed egg shells, and sprinkle it around the plant. The slugs would have to crawl through them to get to the plant, and they get cut up because egg shells are sharp.

  3. I just went out to pick some basil for the first time today and found half a dozen lightning bugs under the leaves. Since you list them as a deterent of slugs, I guess they won't hurt the basil?

  4. I also have a toad living under my tomato plant, so I don't think I'll be having any slug problems!