Carol O'Meara - Colorado State University Extension

Carol O’Meara – Colorado State University Extension

BOULDER – In an election year like this one, it’s good to have a garden that’s waking up early. As canvassers at the door make polite conversation, softening me up before pitching the worthiness of their candidate, they glance about for something to compliment. With herbs, perennials and bulbs all waking up, they pick the garden for their ice breaker.

In return I tell them I miss the snow. Smiles firmly fixed on their faces, they nod knowingly and say thank goodness there’s plenty of snowpack in the mountains for skiers like me. “Oh, I don’t ski,” I reply, leaning slightly closer for emphasis, “I miss the snow because it’s the only thing keeping those creatures away.  They’re out there now, busily – quietly – enacting plans to take over more territory in everyone’s yards.”

A statement like this, delivered with a touch of drama, is enough to pause the canvassers in mid-offering of their candidate’s brochure, unsure if I’m allowed to attend caucus unsupervised. But I’m not unstable; I’m just worried over the lawns.

A dry March is the mitiest month, because it heralds the climax of the smallest nuisances in the yard: Grass mites.   Between feeding on the lawn and entering our homes, they’ve launched a campaign of annoyance.

Perhaps the most startling phenomenon that happens to many in the Front Range is the annual migration of clover mites into our homes. Moving by the hundreds, the tiny, bright orange arachnids clamber walls and slide in around windows. But try asking a stranger at the door if they, too, can see the little aliens invading your home and they’ll usually go to the opponent’s camp and move their signs into your yard. 

Normally, I’m not given to fear-mongering, especially about bugs and arachnids. Outside, Clover mites feed on turf grass or other plants.  They’re unremarkable in the landscape; they don’t damage a lot of the lawn and won’t cart off the cat for a luau on the deck. But they leave a red-orange smear once squished.  Leave a barrier between the lawn and your house to discourage them.

Within, controlling these mites is fairly simple.  Simply place a quarter inch wide line of powder along the window-sill from side to side, being certain that the powder touches the side walls. Any powder works, such as baby powder, corn starch, or baking powder. As the mites crawl into it, they’re rapidly incapacitated, and dry out.  Vacuum it up and apply a fresh barrier every few days until May, after the mites are actively entering homes.

Keep an eye on the lawn; more damaging mites are at the peak of feeding this winter. Hatched in October, mite numbers increase into winter and during warm spells, mite populations explode.  Pointing this out to the canvassers as they turn to leave is a great way to hustle them along, especially if you encourage them to look closely at a mite-infested spot as they leave.

Mites feed by rasping off the leaf surface and sucking up tender, interior cells; the damage appears as small yellow speckles on the grass blades. As feeding intensifies, the grass becomes straw colored and eventually dies, leaving large patches that don’t green up in spring.

This damage is often miss-diagnosed as winterkill or desiccation. If you’ve had mite damaged lawn, take a quick look to see if they’ve returned.  Check the base of the plant for congregations of them during the day.

If you see them, irrigate the lawn to raise humidity or check with a local lawn care company for stronger treatments. Snow cover doesn’t put a stop to their feeding, since it provides protection, but as it melts, the moisture helps drive off the mites.