FOR RELEASE THE WEEK OF JUNE 14, 1999:
I’ve started a kitchen herb garden and am wondering when and how to harvest. Are there any tricks to this or do I just start snipping?
For peak flavor and fragrance, harvest leafy herbs just before the plants bloom, says Jo Ann Robbins, University of Idaho extension educator. Because hot afternoon temperatures dissipate the essential oils, gather herbs in the morning after the dew has dried from the plants. Using a sharp tool and avoiding cutting into woody growth will stimulate new growth throughout the summer.
Annual herbs and established perennials can be harvested for drying at least twice in the season, Robbins says. "For fresh use, go out and pick a few leaves any time. That’s the beauty of growing herbs." Just don’t chop them down to the ground. Whether you’re harvesting for drying or for tonight’s supper, leave at least 4 inches of stem.
To give them time to harden for winter, don’t cut perennial herbs in late summer or early fall. Later in the fall, cut lightly from hardy perennials and from overwintering biennial herbs that are in their first season. According to Robbins, the flavor of some herbs such as sage is improved by a couple of frosts.
Cut annuals and tender perennials–plants that will not overwinter--completely to the ground in the fall before the first expected frost. If they freeze in the garden, these plants will lose most of their herbal value, she says.
We water our lawn for 15 minutes every day, but it’s still not getting enough moisture. What’s the problem?
Turfgrass should be watered deeply, not daily, says Michael Colt, University of Idaho extension horticulturist. Deep watering encourages deep rooting. Frequent, shallow irrigations moisten the blades and soil surface but probably not much else.
For most Idaho soils during peak summer heat, Colt recommends a total of 2 inches of water weekly, divided over two separate applications. Apply water slowly to prevent runoff and to allow infiltration to a depth of 8-12 inches.
To make sure you’re irrigating adequately, set four to five same-sized cans–such as soup cans–under your sprinklers. For a useful average, add up the heights of water you collect in all of the cans and divide by the number of containers. Finally, check to see how deeply the water is penetrating by using a soil probe or spading out and then replacing a small section of turf.
You’re irrigating too much if you squish around on your turf 24 hours after watering.
We’ve had Fusarium wilt in our tomatoes and would like to try solarizing our soil to destroy the disease organisms. When and how should we go about it?
Research suggests that you time your soil solarization attempt for six to eight hot, sunny weeks when you can expect daily temperatures to reliably reach or exceed 80 degrees Fahrenheit. Prepare the soil to a fine tilth and then moisten it. Cover it with clear–not colored--plastic, burying the edges to create a tight seal. Krishna Mohan, UI extension plant disease specialist at Parma, says the moist heat trapped beneath the plastic will "slow-cook" the disease spores, weakening or killing them.
Tilling under the finely chopped green residue of a previous mustard, broccoli, cabbage or cauliflower crop appears to boost the practice’s effectiveness.
According to Mohan, soil solarization can reduce–but not eradicate–the fungal spores responsible for Fusarium and Verticillium wilts and for Pythium, Phytophthora, Fusarium and Rhizoctonia seed rots, root rots and damping off. It also puts the heat on weed populations, weakening or killing seeds.
"You don’t have to treat your whole garden during the same year and forego the whole summer’s production," he says. "You can treat a part of the garden each year and even harvest a cold-tolerant, early maturing vegetable before you start preparing your soil."
I know it’s disgusting, but neighborhood cats sometimes use our raised vegetable bed as a litter box. Does this pose a risk of E. coli 0157:H7 transmission when we eat the vegetables? Besides rinsing, what else should we do?
When vegetables are contaminated with E. coli 0157:H7, rinsing won’t make them safe to eat, says University of Idaho microbiologist Carolyn Bohach: thorough cooking is required.
Fortunately, no cat has yet cultured positive for E. coli 0157:H7–although the frisky felines are notorious for carrying toxoplasmosis. (A parasitic disease that can cause swollen lymph nodes, fever, sore throat and other symptoms in adults and that can kill unborn children, toxoplasmosis is the reason pregnant women are advised not to handle litter boxes.)
Bohach isn’t absolutely convinced that raw cat manure is risk-free when it comes to E. coli 0157:H7. "Very few cats have been tested, so we can’t conclude that they never carry it," she says.
Cats–like weeds–are attracted to bare soil. Discourage them with straw or fabric mulches, window screening or netting, or small sticks poked into the ground.