Pull beets 60 to 80 days after seeding, not after they sprout. In Colorado, a sowing made two to three weeks before the last frost comes ready between about June 9 and July 16. The harvest window is only half the story. Once the roots are out, the usual root-crop instinct (get them as cold as possible) works against you. Topped beets keep best at 33 to 36 F, and the USDA says storage at 32 to 34 F produces more black spot and rot.
The short answer
Colorado’s state soil is the Seitz series, an Alfisol: a forest soil of moderate fertility that holds nutrients reasonably well. USDA’s representative surface values come to 42 percent sand, 21 percent clay and 37 percent silt, a loam to silt texture, well drained, with a surface pH of about 5.6 (slightly acid). Utah State University Extension says beets want deep, sandy, well-drained soil rich in organic matter. Seitz matches that on drainage. It is less sandy than the ideal, and with 21 percent clay it will hold more water than a sandy bed. It should not pond, though, and a beet root can push down through a loam like this without much fuss.
Treat all of that as a starting point. Colorado spans hundreds of soil series, and these figures are the representative values USDA records for the mapped surface of one series, not a measurement of a worked garden bed. River bottoms, foothill slopes and any yard a builder has scraped or filled will differ, sometimes completely. The organic matter figure of about 70.0 percent shows that the mapped surface is a natural forest litter layer, and no cultivated bed looks like that. Utah State University Extension recommends amending beet ground with no more than 1 inch of composted organic matter per 100 sq ft. Your own pH and texture come from a soil test, and Beet Soil in Colorado: What the Root Will Meet walks through what to ask of one.
Heat is a separate problem from soil
Utah State University Extension ties woodiness to heat above 85 F combined with water stress. How many days a year Denver passes 90 F is not published in the data behind this page, so there is no count here, and a guess would be worse than a blank. What the data does hold is the frost side of the calendar. NOAA NCEI puts the last spring 32 F freeze in Denver between May 1 and May 11 (the 30 to 70 percent probability band). Denver sits at 5,280 feet on the plains. Mountain towns run far shorter seasons and can frost in July, and the western slope differs again.
The practical reading: a root still in the ground when midsummer heat arrives is the one at risk of turning woody, especially if the bed dries out. So lean toward the early end of the 60 to 80 day range rather than the late end. If you want the whole season laid out, Growing Beets in Colorado covers it from seed to harvest.
The six weeks that decide it here
Count back from the frost band. Sowing two to three weeks before a last freeze that falls between May 1 and May 11 means seed goes in between roughly April 10 and April 27. Beets are sown in place, so the 60 to 80 days run from seeding, never from a transplant date. Add them up and the earliest pull lands around June 9, the latest around July 16. Pulling on that schedule means the roots finish before the worst of summer, which is the whole point of sowing early.
What a Colorado spring usually does
The Front Range spring tends to swing. A warm, dry week can be followed by wet snow, then wind, then another dry stretch. Seedlings in April soil go through all of it. The stretches that matter most for beets are the dry ones, because the surface of a well-drained loam like Seitz sheds water and dries from the top down, and a beet seedling is rooted in exactly that top layer. Rainfall totals for spring are not part of the verified data here, so take this as the usual pattern, not a forecast.
Where the bolting risk sits
Utah State University Extension is specific: water stress in the first six weeks causes premature flowering. For an April 10 to April 27 sowing, those six weeks end between about May 22 and June 8, and they cover the driest, windiest, most changeable part of the Colorado spring. That is where bolting risk sits. A plant that sends up a flower stalk early has been told, by thirst, that its season is ending. Check the top inch of soil every day or two during dry weather, and water before the seedbed crusts.
Once week six passes, that risk fades and a different one takes over: heat above 85 F with water stress, which makes the root woody. The two failures have different causes and different timing, and one steady watering habit does not cover both. Pests also keep their own calendar over these same weeks, which What Eats Beet in Colorado, and When maps out.
When the day count is up, pull and top the roots right away. Bunched beets with leaves attached keep only 10 to 14 days at 32 F and above 98 percent relative humidity, according to USDA Agricultural Handbook 66.
What goes wrong here
- Bolting after a dry spell. Thirst in the first six weeks sends the plant to flower. Keep the seedbed evenly moist from sowing through about the first week of June, and don’t count on rescuing a plant once the stalk shows.
- Woody roots from heat. Heat above 85 F with water stress, later in the season, toughens the root. Pull on the early side of the 60 to 80 day window and water deeply through hot spells.
- Over-amended beds. A bag of compost is not a license to dump it. Stay under 1 inch of composted organic matter per 100 sq ft, and don’t read the 70.0 percent mapped figure as a target.
- Scraped or compacted ground. New-construction yards often sit on subsoil that was stripped or filled, and beets want depth. Loosen the bed deeply before sowing, and get a soil test to see what you are working with.
- Storing too cold. At 32 to 34 F, black spot and rot run higher than at a little warmer. Aim for 33 to 36 F and 98 percent humidity for topped roots. In a cellar, pit or clamp, stay between 31 F and 41 F, and put a thermometer in to check.
- Storing with the tops on. Leaves pull moisture from the root and shorten its life to 10 to 14 days. Cut them off at harvest.
- Storing the small roots. Small roots lose water and shrivel faster. Keep the big ones for storage and eat the small ones first.
Common questions
How do I know a beet is ready to pull?
Start with the calendar: 60 to 80 days from seeding. The sources behind this page give no root size to aim for, so go by that count and by what you want on the plate. Brush the soil back from the shoulder of one root, and if it looks right, pull the rest.
Can I leave beets in the ground through July and August?
You can, but you are taking a risk. Heat above 85 F with water stress makes the root woody, and a Colorado summer can pair the two easily. An early sowing that you pull in June or early July sidesteps most of that.
What temperature should I store topped beets at?
Between 33 and 36 F, with relative humidity at 98 percent, per USDA Agricultural Handbook 66. The same source says storage at 32 to 34 F produces more black spot and rot. Pits and cellars should stay between 31 F and 41 F.
Which beets should I store and which should I eat first?
Eat the small roots first and store the big ones. The USDA handbook notes that large roots keep much better because they lose water and shrivel more slowly. Bunched beets with leaves attached last only 10 to 14 days at 32 F, so top them first.