Greetings fellow growers and floral designers, seed producers, plant breeders, agriculture educators, policy makers, wholesalers, writers, and everyone else connected with the production and distribution of fresh cut flowers. Here in the northeastern states and Canadian Maritime Provinces we’ve had a luxuriously long spring. Steady weather has allowed for prolonged harvest of flowering branches, early bulbs, and winter annuals. Highlights for us have been star magnolias (white, pink, and yellow), two months of tulip harvest, and several nigella varieties that grow strong and tall in these cooler temperatures, but bolt short and weak when the weather heats up fast.

Fortunately, nigella is not attractive to the voracious pill bugs that love the environment in our greenhouse beds. Our greenhouse functions as both in-ground season extension space and benches for seedlings. The in-ground beds produce early season crops; the benches hold seedlings until they’re strong enough to be moved outside to harden off. We had a plague of pill bugs that colonized the in-ground beds, decimating some crops (tuberose, star-of-Bethlehem, saponaria), while not at all interested in others (lily, agrostemma, nigella, crocosmia). They especially love saponaria stems – every morning we’d find several plants toppled over and a pile of pill bugs huddled at the base of the stem.

Then we noticed holes on the leaves of the young ageratum transplants. Inspecting the leaves’ undersides revealed armies of pill bugs, happily munching away in broad daylight. Though the ageratum plants would successfully grow past the infestation (the leaves of more mature plants aren’t appealing to the bugs), still it was time to get serious. We tried three approaches to minimize their impact:

1.  Sluggo. The active ingredient is iron phosphate, a compound that breaks down into fertilizer. Once the bugs have consumed the Sluggo, they cease eating and crawl off to die from iron overdose. Although Sluggo is approved by OMRI (Organic Materials Review Institute), several sites question the safety of this product, based on an unlisted ‘inert ingredient’ called EDTA. Google ‘sluggo inert ingredients’ to read all about it!


2.  Diatomaceous earth is a naturally-occurring siliceous rock that is crumbled into a powder and sprinkled on the soil surface. The silica is supposed to act as a mechanical insecticide, due to its abrasiveness that causes the bugs to dehydrate. However, we saw pill bugs marching across the stuff without any aversion, since it appeared to be quite sodden after taking on moisture from the soil itself.

3.  Beer. Save lots of tuna or cat food cans, set them into the soil, fill with any type of beer you don’t mind parting with, and you’ll be thrilled with your daily catch—a can full of drowned critters. Empty daily before they ferment into a new micro-brew. Obvious results, most cost-effective method—I recommend it.

Even though all the greenhouse crops (except saponaria) survived the pill bug plague, the beer diet hasn’t completely eradicated them. Dig around and there they are, lurking beneath the edges of the landscape fabric, waiting for the next mini-keg to arrive and the party to continue. Our plan is to put chickens in the greenhouse once the early-season crops are finished, then sit back while they dine on pill bugs and fertilize the beds. But first I’ll trial the idea by tossing a few handfuls of roly-polys to the chickens to be sure they find them palatable.

Pill Bug Fun Facts

A pill bug goes by many names: roly poly, wood louse, armadillo bug, potato bug. They curl into tight balls when threatened, hence the nickname roly poly. Their ability to curl up distinguishes them from another close relative, the sow bug.

Their blood is blue. Many crustaceans, pill bugs included, have hemocyanin in their blood. Unlike hemoglobin, which contains iron, hemocyanin contains copper ions. When oxygenated, pill bug blood appears blue.

Pill bugs are crustaceans, not insects. Though they’re often associated with insects and are referred to as “bugs,” they actually belong to the subphylum Crustacea.They’re much more closely related to shrimp and crayfish than to any kind of insect.

Diana Doll

StrayCat Flower Farm

Diana Doll StrayCat Flower Farm Contact her at [email protected]