You're new to the Treasure Valley and love to garden.Congratulations. You'll fit right in.
"Gardening is very popular in this area," Master Garden Program assistant Lynnette Flerchinger of the University of Idaho Extension Office said. "We have garden clubs of every sort. Our master gardening class has 50 people and a waiting list."
North Carolina transplant Elaine Walker, one of the program's students, was surprised by the level of interest.
"In North Carolina, we had 16 in the class and only eight finished," Walker said. "They're thinking of cutting the class back to every other year."
Even in the garden-happy Treasure Valley, however, gardening is challenging. In fact, the area's long, hot summers, lack of rain and variety of soil conditions can make it especially challenging. Knowing the basics will help you save time and money and minimize frustration. Here's what you need to know.
WHEN TO PLANT: This part of Idaho is in the U.S. Department of Agriculture's Hardiness Zone 6. Our range of average annual minimum temperatures is zero degrees to 10 degrees below zero. In Boise, the average date of last frost varies from May 6 at the airport to May 10 at Lucky Peak. Either wait until then to put out tender plants or plan on covering them up on cold nights.
"I wait until the snow is gone from Shaffer Butte (the peak overlooking Bogus Basin) before planting corn," Flerchinger said. "By then the cold air is high enough it won't get down to the Valley."
SOIL: The thing to remember about average soil conditions here is that there aren't any. Soil types very widely; the type you have depends on where you live.
If you live on one of the Boise Benches, your soil is likely to be heavy clay. Some parts of the Valley have sandy soil. If you live near the Boise River, you may well be inclined to think your "soil" is mostly rocks.
You can get a fair idea of the type of soil you have, Flerchinger says, by testing it yourself. Put a clump of it in a jar and fill the jar with water. Put a lid on, shake it and let everything settle. Clay will rise to the top, sand will sink to the bottom and silt will settle in the middle. Eyeballing the result will give you an idea of the percentages of each. The one with the highest percentage is your basic soil condition.
Soil-testing kits that provide additional information are sold at nurseries. For more details, you can pay the University of Idaho's analytical sciences lab to test your soil. Costs vary depending on how much detail you want. For information, call 208 885-6275.
Regardless of the type of soil you have, it's likely to need compost or other organic material.
"Some areas like the North End have been settled long enough that the soil is loamy," Flerchinger said. "But even then you need to continually add organic matter because it mineralizes and breaks down. The best time of year to apply it is in the fall."
Most soils in the Treasure Valley are alkaline and may need phosphorus. Liquid fertilizers or slow-release fertilizer granules may be added during the growing season.
WATERING: How often you need to water depends to a significant degree on the type of soil you have. The soil type doesn't change how much water plants need, but it does change the intervals between watering.
Sandy soil doesn't hold water and may require light, daily applications. Heavy silt or clay soils may need water only every five or six days, but the applications need to be heavier. Water penetration can be improved in clay soils by adding organic matter.
The amount of water used also depends on the types of plants you have and the type of irrigation system. If you're starting your yard from scratch, you'd be wise to consider drip irrigation and native plants and grasses that need relatively little water.
Don't let the Valley's shade trees and green lawns fool you. This is a desert. Droughts and water shortages are facts of life. Planting climate-appropriate vegetation will not only save precious water; it can result in less frustration and an attractive, low-maintenance landscape.
"If the sun beats on it and you don't want to use a lot of water, try black-eyed Susans, wildflowers and rabbitbrush," Flerchinger said.
In the fall, be sure to water trees deeply enough to saturate the root zone. Too little water in the fall can mean a dead tree the following spring.
Go to IdahoStatesman.com for help in calculating water requirements for trees and lawns, and for information on garden-related subjects, from ornamentals to fruits and vegetables.
Tim Woodward: 377-6409
