Thursday, September 21, 2000
I have two very small flowerbeds on my property, one on the right side of our garage and one on the left. Both have been homes to Alice du Pont Mandevillas, aphids, sowbugs, earwigs, and Argentine Ant nests for five years.
In the right bed I spread a layer of worm castings about 1 inch thick and watered it according to the instructions provided by the Wormgold company.
Three hours later the bed was full of exit holes from sowbugs and earwigs (I knew which insects made the holes because I could see them climbing out of the ground and scurrying to the concrete walkway).
Even the ants have moved their traffic lanes a few inches, away from the bed of the ground to the concrete walkway beside it.
If the bed does not contain ants, sow bugs or earwigs after several months, I would consider myself satisfied with Hahn’s claims that insects hate to even walk on worm castings. However, I wonder if a layer of steer manure would provide the same results.
I also put a one-inch thick layer of worm castings underneath two of Sophie’s whitefly-infested hibiscus plants (she has five).
In watering these worm castings down, we hosed off all of the white, cottony masses left by the whiteflies so the leaves look fresh and clean. Sophie says she hoses the plants off every week, only to have the whiteflies return within 48 hours.
Friday, September 22, 2000
It rained lightly most of the afternoon and evening. Sow bugs are still climbing out of the bed of worm castings. The ant trails remain on the concrete walkway, but a new ant trail has formed on the worm castings. It starts on the walkway, crosses the worm castings and disappears into the brick siding of the garage.
Saturday, September 23, 2000
The new ant trail is, if anything, a little wider than before.
Sunday, September 24, 2000
The ants are gone. All that remains of the trail is a footpath worn into the powdery worm castings by millions of tiny feet. All ants are out of the bed, too. In the past, if I did any weeding or digging in the bed, I would soon be covered with ants. But today when I poked a dandelion digger deep into the bed, not a single ant appeared.
Monday, September 25 through Thursday, September 28, 2000
No ants in the bed.
Friday, September 29, 2000
The ants have returned. The sprinkler doesn’t cover the entire bed very well and there are little holes in the dry part where they’re entering and exiting.
Saturday, September 30, 2000
I adjusted the sprinkler head to cover the bed more thoroughly this morning. The ants took off, because by this evening, there are none in the bed.
Sunday, October 1, 2000
They’re ba-a-a-ck.
Monday, October 2 through Thursday, October 4, 2000
Ants remain in the bed. When I soak the bed on Thursday, they climbed out of the holes in the worm castings, carrying their larvae and eggs to higher ground, proving that have, indeed, made themselves most comfortable in the bed.
Sophie’s hibiscus are once again covered with whiteflies, but for those plants I’m giving the worm castings two months to work, the same amount of time it took the Los Angeles Times garden writer to see results.
March 15, 2001
It’s been several months, not just two! The whiteflies, while certainly diminished, are still present. We’ve had a lot of rain, which washes them off, but they come back quickly with the dry weather. Sophie thinks it’s about time to put these poor hibiscuses out of their misery.
April 1, 2001
It has been over five months since I applied worm castings as directed by the Wormgold instructions, and there are definitely ants in the flower beds. The Mandevillas are still struggling against aphids, which the ants ferociously protect from any predators. Sow bugs and earwigs have returned to the beds, too.
Sophie’s hibiscus plants are covered with whiteflies and I have to agree with Sophie… it’s time to conclude our experiment. While the castings may have caused the earwigs and sow bugs to exit the flower beds the repellency effect does not seem to last more than a few months against those critters, and seems to have no effect whatsoever on aphids, whiteflies, or Argentine Ants.
I do believe that healthy plants naturally repel insects, and perhaps worm castings will strengthen a plant with its superior fertilizing qualities, but the bags of Wormgold worm castings I applied did not seem to help these plants repel ants, aphids, or whiteflies.