Slugs in Colorado: When It Shows Up and What Stops It
Slugs show up in Colorado mostly where someone is watering something. In a state where annual precipitation averages under 17 inches in most cities…
Gardening in Colorado
Everything we have worked out for Colorado: 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 Denver, the last spring freeze runs May 1 to May 11 and the first fall freeze runs September 30 to October 12, USDA zones 3b-7b, 3,401 growing degree days in the year.
Garlic does well: 30.4 weeks below 40 °F, comfortably past the six it needs to form a proper head.
Elsewhere on the property in Colorado: 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.
Corn earworm in Colorado: When It Shows Up and What Stops It
Corn earworm doesn’t overwinter in Colorado’s frozen ground, so its arrival depends entirely on when moths ride storm winds up from Texas and Oklahoma.
Spotted cucumber beetle in Colorado: When It Shows Up and What Stops It
Spotted cucumber beetles start turning up in Colorado gardens in late May at lower elevations and can persist into September, with the heaviest pressure…
Flea beetles in Colorado: When It Shows Up and What Stops It
Flea beetles wake up in Colorado when soil temperatures climb into the 50s, which typically happens between mid-April and early May along the Front…
Harlequin bug in Colorado: When It Shows Up and What Stops It
Harlequin bugs show up in Colorado gardens mainly in late spring through summer, typically from May through August, concentrated along the Front Range in…
Garden Pests in Colorado: What Shows Up, When, and How to Stop It
A season-by-season look at the ten pests Colorado State University Extension tracks in home gardens, with damage clues and real fixes.
Colorado Lawn Care: What to Plant and When to Feed It
Colorado sits in a lawn-grass transition zone according to Denver’s climate normals, and choosing, seeding, feeding, and mowing all depend on which grass you plant.
Garlic Varieties That Suit Colorado Winters
Colorado’s fourteen proven garlic cultivars all go into the ground in September, timed against NOAA’s Denver-area first fall freeze range, whatever variety you choose.
When to Plant Garlic in Colorado: Counting Back From the First Frost
Colorado’s fall garlic planting window runs early to late September, set against NOAA’s Denver-area frost data, with adjustments for elevation and local microclimate.
Growing Garlic in Colorado: Planting Dates, Varieties and Winter Cold
A practical guide to fall planting dates, hardneck and softneck varieties, soil prep and winter mulch for growing garlic in Colorado.