Garden docs: Are ‘roly-poly' bugs a problem?

Mira M. of Sebastopol asks: I have quite a few of those ‘roly-poly’ bugs in my garden. A friend called them ‘sowbugs.” Are they a bug that I need to control? Will they do any damage to my plants?

Answer: Compared to other insects, rolypoly bugs, aka sowbugs, aka pillbugs, are low on the enemies list. They usually eat decaying organic matter, but they also like to chew on tender stems and young seedlings. If you have a problem with your plants, you can sprinkle diatomaceous earth, or washed crushed eggshells, around the little plants.

Jeanne W. of Sonoma asks: How can I tell if a plant can be divided?

Answer: To tell whether a perennial can be divided, look closely at the base for spreading roots, rhizomes or stolons. You’ll see many stems coming out of the ground, not just one or two. If you see many, then it can be divided. If they’re not divided every 3 years or so, they’ll soon overtake other plants or the garden. The old centers then die out as the plant gets older and older, ruining the beauty of the plant.

Many common flowering perennials do spread and need dividing, including Agapanthus, Alstroemeria, Armeria, Aster, Astilbe, Campanula, Coreopsis, Geum, Helenium, Hemerocallis, Lychnis, Rudbeckia, Stachys and Veronica. Some will actually grow poorly if they’re not divided and restarted in amended soil as often as every two to three years.

To divide a perennial clump, use a sharpened flat-bladed spade, not a shovel. Push the spade into the root mass to break off good-sized pieces - those that are about six inches across will become established faster than smaller pieces. Dig these vigorous outer pieces from the ground, then dig out the tired old center part and toss it into the compost pile.

Sometimes it’s easier to dig the whole clump out of the ground and then split it with the sharpened spade or knife. If the roots are too tough, cut sections apart with an inexpensive, long, serrated kitchen knife.

Try to plant the pieces at the same depth they were before you divided them. As a bonus, you’ll have enough extra plants to pot up and give to your friends.

Steve H. of Healdsburg asks: Is there a way to keep my leafy vegetables from bolting as the weather warms up? I would like to keep them going for as long as possible.

Answer: To delay the inevitable ‘bolting’ process (where the plant stops producing leaves and start developing the seed stalk), to your kale, lettuces, Oriental greens, Swiss chard, etc., keep the soil moist and cover the plants with a floating row cover or some shade cloth. If you don’t have any, then use anything that will help keep the afternoon sun off the plants. Even an umbrella anchored into the ground will work. You can remove it when it gets cool, and put it back on when it gets hot. This will help slow the bolting process.

Dana Lozano and Gwen Kilchherr are garden consultants. Send your gardening questions to The Garden Doctors, at pdgardendoctor@gmail.com. The Garden Doctors can answer questions only through their column, which appears twice a month in the newspaper and online at pressdemocrat.com.