Will Spinach Bolt Early in Colorado?
Spinach bolts early almost everywhere along Colorado’s Front Range, and the trigger is daylight, not the mountain air staying cool.
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.
When to Sow Pumpkins in Colorado
Most Colorado gardeners get this right by sowing pumpkin seed outdoors between mid-May and the first week of June, once the soil has warmed past 65 F.
Will Pumpkins Ripen Before Frost in Colorado?
Pumpkins can ripen before frost in Colorado, but only if the flower that made that fruit opened by roughly mid-August.
When to Sow Parsnips in Colorado
Denver’s frost calendar answers this in one line: sow parsnip seed directly in the ground 2 to 3 weeks before the last spring frost, which falls between…
Will Parsnips Sweeten in Colorado?
Yes, parsnips will sweeten in Colorado, at least along the Front Range where Denver’s climate data applies.
Growing Spinach in Colorado: When Will It Bolt?
Spinach in Colorado runs on borrowed time twice a year. In spring, the crop is racing a calendar that closes as day length climbs past 14 hours; by early…
When to Sow Carrots in Colorado: Counting Back From the Last Frost
Colorado carrots go into the ground directly, seeded in place a few weeks ahead of the last frost since young plants shrug off a light chill.
Will Carrots Fork in Colorado Soil?
Not likely, based on the soil that represents Colorado. That soil drains well and holds a moderate share of clay, the kind of ground that lets a carrot…
When to Sow Beets in Colorado
The straightforward answer: sow beet seed directly in the ground two to three weeks before your local last frost date.
Beet Soil in Colorado: What the Root Will Meet
In Colorado, a beet root generally meets ground that’s better than its reputation: well-drained, slightly acid, with enough sand mixed in to let a…