FOR RELEASE THE WEEK OF MARCH 8, 1999:
We’d like to plant some trees this spring and are wondering how to tell when the ground is ready.
You’ll want your soil to be warm enough and dry enough. It’s warm enough if it’s at least 40 degrees Fahrenheit four to five inches below the surface, says Yvonne Carree, University of Idaho extension forestry associate. To determine if it’s dry enough:
Dig a hole about a foot wide and a foot deep, then fill it back in. If the backfill comes up short and you can’t refill the hole completely, the conditions are too wet; working wet soils invites compaction, so hold off until the soil is drier. On the other hand, if you have too much soil left, it’s too dry; go ahead and plant, but water your new trees immediately.
"If you fill the test hole and have a couple of handfuls of soil left over, the moisture is just right for planting your trees," Carree says.
In the health food store, I saw advertisements that "genistein" can prevent cancer. What is it and does it really work?
Genistein is a chemical compound found in soy, says Martha Raidl, University of Idaho extension nutrition specialist. In laboratory test tubes and in animals, it has limited the growth of breast and prostate cells. Human cancer studies are under way.
We’ve already got aphids again on our roses, ash trees and peach trees. Is it too late to use dormant spray?
If the buds have begun to break and green leaves are showing, it’s too late, says Bob Stoltz, University of Idaho extension entomologist. Any insecticide spray–even a mild insecticidal soap–can burn tender young leaves. But if the swollen buds are still intact, go ahead and apply dormant spray when temperatures will be above freezing for at least a day (and preferably when they’ll be above 50 degrees Fahrenheit).
Chances are, if you had aphids on your roses, ash trees or fruit trees last spring, those aphids will have returned to the plants in the fall to lay their eggs. Without a dormant treatment lying in wait, the eggs will hatch as temperatures warm and the aphids will begin to feed. On ash and fruit trees, that feeding will curl and distort leaves–a harmless but unsightly condition that will last all season and that will protect the aphids inside from sprays.
Applying systemic insecticides to the soil around your roses is a good alternative this time of year, Stoltz says. For early-season aphid control in trees, systemic insecticides are best applied in the fall or early spring, depending on the chemical used.
Which raspberry varieties do you recommend for Idaho?
The two main problems we have with raspberries in Idaho are winter injury and root rot, says Danny Barney, University of Idaho extension horticulturist. For best results, pick varieties that are hardy enough for your area. Watering and fertilizing these adapted varieties regularly, combined with good weed control, will ensure healthy plants that tolerate winter’s stresses. To reduce root rot, plant your raspberries in raised beds or on 1-foot-high by 2-foot-wide ridges.
"Provided that you start with healthy, virus-free nursery plants, you can plant red, yellow, purple and black varieties together," Barney says. Listing the best-adapted varieties first for each color, he recommends:
For the Panhandle: Munger and Jewel (blacks); Brandywine, Royalty and Success (purples); Summit, Autumn Bliss, Amity and Heritage (red everbearings); Killarney, Newburgh, Haida, Taylor and Chilcotin (red summer bearings), and Amber and Fall Gold (yellow everbearings).
For southwestern Idaho and Lewiston: Munger, Jewel and Haut (blacks); Brandywine, Royalty and Success (purples); Summit, Autumn Bliss, Heritage, Amity and Scepter (red everbearings); Skeena, Newburgh, Haida, Taylor, Chilcotin and Killarney (red summer bearings), and Amber and Fall Gold (yellow everbearings).
For central and southeastern Idaho: Royalty, Brandywine and Success (purples); Summit and Autumn Bliss (red everbearings); Killarney and Boyne (red summer bearings), and Amber and Fall Gold (yellow everbearings). In these colder parts of Idaho, black raspberries aren’t hardy enough to be reliable, although Munger is probably the best, Barney says. Short seasons also make fall harvests questionable for red and yellow everbearings.