Margaret Lauterbach

How to identify, prevent curly top virus

Curly top virus, common in our area, seems minor or absent some years; other years it’s destroying gardens all over the Valley. I’ve heard of several gardens afflicted with this virus this year. Curly top is a virus spread by a tiny beet leafhopper, and if you’re not near beet fields (such as sugar beets), be aware these leafhoppers can ride the winds for up to 200 miles.

Whatever they bite transmits the virus to them. They do not suffer ill effects, but the next thing they bite receives the virus. One favored plant is tomato. Large vigorous tomato plants suddenly curl top leaves, showing purple veins on what had been the undersides of the leaves. Leaves at this point feel leathery. I discard tomatoes from diseased plants. Curly top virus may also damage and kill beets, squash, peppers, spinach, celery, melons, potatoes and several ornamental plants. In leafy plants, symptoms are distorted and discolored leaves, swollen dark veins, stunting of the plant and/or deformation of fruit.

Curly top virus is climate specific, occurring in arid areas such as the desert areas of the Middle East and the Intermountain West, from Canada to Mexico. If winds blow in the right direction, it may invade southeastern Colorado. The other “outside its normal range” area is the east Bay Area of California. Some years it has devastated the commercial chile pepper crop in southern New Mexico.

You may prevent the virus by planting tomato varieties known to be resistant to curly top virus, by shading crops that don’t require full sun exposure, or surrounding or interplanting treasured plants with strong-smelling herbs such as dill. The tomato varieties known to be resistant to that virus are all salad types of tomatoes; varieties are Rowpac, Columbia, Latah, Payette, Owyhee, Roza and Saladmaster. The only commercial seed source I know of for them is Sand Hill Preservation Center ( These seed vendors don’t claim that resistance, but these varieties were developed and tested by University of Idaho faculty members many years ago.

Keeping deer away

If you have deer predations in your garden, here’s an easy, inexpensive repellant. Scott Kunst, owner of Old House Gardens bulb and plant company in Ann Arbor, Mich., — and frequent visitor to Boise — included this tip in his latest blog: Get Vicks VapoRub on your thumb and forefinger, then lightly pinch plants deer have been devouring. It shouldn’t be necessary to touch all of the plants in a bed, but just here and there, pinching parts that will continue to thrive in that bed (not flowers). The strong odor might confuse and repel beet leafhoppers, too. Mentholatum might work too, if it’s as powerfully scented as it used to be.

Time to harvest garlic

Have you harvested your garlic yet? I planted mine on the shortest day of the year, harvested on the longest day. I didn’t have a cool place to cure it, so I laid it out on the wire “bench” in my shaded greenhouse. It’s better to dig it a little early than too late, because if you harvest it too late, the head will break apart and not keep until time to replant. Cure it in shade, preferably some cool area, for a couple of weeks before removing the stem.

Some garlic varieties have bulbils, small bulbs at what would be a seedhead in other plants (garlic doesn’t set true seed); other varieties produce small hard bulblets around the garlic head, some visible under the outer skin. You can plant either of these small bulblets or bulbils, but in one year they’ll just produce a single bulb. You can then replant that, and that will produce a head of cloves in another season. If you want to plant the hard bulblets, it helps to break the hold the hard coat has on the bulb by cutting it (not at the head or the base).

Send garden questions to or Gardening, The Statesman, P.O. Box 40, Boise, ID 83707.