Winter bug wars

Gypsy moth, with egg mass         Wisconsin Dept.of Natural Resources

Gypsy moth, with egg mass         Wisconsin Dept.of Natural Resources

More often than not, we in the Northeast experience a respite from the cold toward the end of January — in fact, it will be close to 50 this weekend.

Gardeners who have been nodding over their seed catalogs in stuffy, overheated rooms are ready to poke their noses outside and have a turn around the yard to see how things are faring. There’s still time before new growth starts to abort common plant diseases and tamper with the balance of good bugs vs. bad bugs — all without nasty pesticides.

Certain diseases can overwinter on dead leaves left lying at the feet of the victim, and raking them up now can help thwart a new cycle of pestilence. To get your heart rate up and keep yourself warm outdoors, grab a rake and head for the garden.

First check your roses, which by now should be largely defoliated. If you had troubles last year with black spot or powdery mildew, spores of these maladies can still be lurking in the dead rose leaves.

Rake them up, and if you’re feeling really ambitious, remove any faded leaves that may be clinging to the canes. Don’t compost them, lest the disease spores proliferate in your pile, but rather bag the leaves up and throw them away.

Next, look over your German (bearded) irises. Their only serious pest is the iris borer, which loves to huddle among the spent, sword-shaped leaves of this favorite perennial. Gather up the dead fronds and whack any fans of leaves remaining on the plant to about 6 inches. Here, too, is trash that should go in the garbage, not the compost bin.

You should be pretty toasty by now, but don’t stop yet — head for the peonies. Did you cut away and discard their foliage at the end of the season? No? You’re leaving yourself open to heartbreak, since botrytis blight can infect peony flower buds, leaving them blasted and blackened, and unable to open.

Cut any withered foliage back to the plant’s base. You know the drill — into the garbage with them. Other plants you can safeguard in this way from over-wintering diseases include lilies, phlox, bee balm (Monarda) and crocosmia, a vivid, late-blooming bulb whose acquaintance you should make, if you haven’t already.

Preying mantis egg case       Indiana Ivy Nature Photo/Flickr

Preying mantis egg case       Indiana Ivy Nature Photo/Flickr

Don’t head back indoors until you’ve inspected your evergreens. The evil bagworm, especially fond of arborvitae, junipers and pine, builds itself a case that resembles an immature pine cone. Hidden inside are hundreds of eggs that will hatch in spring, sending hungry hordes of worms out to defoliate your shrubs and trees.

Hand-pick and trash as many of these as you can to reduce populations. Controls like Bt, a bacterium that afflicts caterpillars, are only effective in late May and early June when the critters are small. Once they get older and wiser, these night-feeding worms retreat into their tough bags where pesticides can’t touch them.

Check the trunks of your deciduous trees, too, for gypsy moth eggs, which look like patches of beige foam on the bark. As with bagworm, removing them now, before they can hatch, is a pre-emptive strike that will make your trees happy and reduce any inclination to resort to pesticide treatments later on.

While you’re working, keep an eye out for the good guys. Once you recognize the egg case of the praying mantis, you may well find a few stuck to the branches of shrubs, perennials or small evergreens.

I nip off twigs with cases whenever I find them, and prop them up in the garden. Mantises are kind of neutral in the bug wars, eating harmful and beneficial types indiscriminately, but they’re fun to have around with their alien little faces and pious postures.

If you’re lucky, on some warm day in early June you may witness, as I once did, the sudden eruption of hundreds of tiny, perfectly formed mantid kids from this case that looks a ball of solidified meringue. They boil out and disperse on scampering little feet, running for their lives.

If they didn’t, their cannibalistic little siblings might make of them a first and fratricidal breakfast. That’s nature for you, red in tooth and claw, weaving mysterious patterns we don’t have to understand fully to appreciate.