When Sweet Corn Is Ready in Idaho, and How Fast It Fades
Sweet corn in Idaho goes in when the soil, measured 4 inches down, holds at about 60 F. That day arrives well after the last frost, not with it.
Idaho
For homeowners and renters in Idaho: the planting calendar, the maintenance schedule and the local programs worth knowing about.
Gardening in Idaho
Everything we have worked out for Idaho: what to plant and when, which varieties finish in time, the pests that actually turn up here, and the jobs that pay off month by month. We also cover the rest of the property, from lawns and soil to home care and energy, because a garden rarely stops at the vegetable bed.
The numbers first, because everything else follows from them. Measured at the weather station in Boise, the last spring freeze runs April 23 to May 7 and the first fall freeze runs October 7 to October 21, USDA zones 3b-7b, 3,309 growing degree days in the year.
Garlic does well: 26.1 weeks below 40 °F, comfortably past the six it needs to form a proper head.
Elsewhere on the property in Idaho: the pests that turn up here.
Figures from NOAA's 1991-2020 climate normals. A state is not one climate: elevation, a large lake or the coast can move these dates by two weeks either way, so check your own county with the extension service before you spend money.
When to Stop Cutting Asparagus in Idaho, and How to Keep the Spears
Stop cutting when most of the spears coming up are thinner than a pencil. That is the signal, and no calendar date replaces it.
Heat Pump or Gas Furnace in Idaho: Which Costs Less to Run?
For the same house and the same winter, a natural gas furnace costs less to run in Idaho than a heat pump, and electric baseboard costs the most of the…
When to Plant Grass Seed in Idaho
For most Idaho lawns, the best time to sow grass seed is late summer into early fall, while the soil is still warm and frost is weeks away.
When to Dethatch a Lawn in Idaho
Most Idaho lawns never need dethatching. Before you rent a machine, cut a wedge out of the turf and measure the spongy brown layer under the green.
How High to Mow a Lawn in Idaho
Mow tall fescue at 3 to 3.5 inches, Kentucky bluegrass at 2 to 3, perennial ryegrass at 1.5 to 2.5, and zoysiagrass or bermudagrass at 1 to 2.
When to Aerate a Lawn in Idaho
Aerate a cool-season lawn in Idaho in fall, while the grass is still growing, and finish before the first frost.
When to Winterize Sprinklers and Outdoor Faucets in Idaho
Finish before the first hard freeze. In the Boise valley, NOAA’s 1991-2020 Climate Normals put the first 32°F freeze between October 7 and October 21…
How Late Can You Plant Trees and Shrubs in Fall in Idaho?
For Boise, the conservative deadline for planting trees and shrubs in fall runs from August 26 to September 9, which is six weeks before the first fall…
When to Mulch Strawberries and Perennials for Winter in Idaho
Wait for the ground to start freezing. In Boise, NOAA’s 1991-2020 Climate Normals put the first 32°F freeze between October 7 and October 21, and winter…