What to plant in June in Colorado
In Colorado (CO), June is the heart of the growing season - about 6 weeks after the last frost (May 5) and 15 weeks before the first (October 1). The state averages 149 frost-free days a year (last frost May 5, first frost October 1; USDA zones 3b, 4b, 5a, 5b, 6a, 7a).
45 crops have a sowing or planting window this month, including basil, bitter melon, cantaloupe / muskmelon, chayote, cucamelon, cucumber - and 17 of those windows close during June.
Dates here come from Colorado frost dates (last frost May 5, first frost Oct 1). For one crop in detail, see when to plant basil, cantaloupe or cucumber in Colorado.
Colorado covers a very wide range of climates, so dates near you can be two weeks or more either side of these. Enter your ZIP code in the planting calendar for dates tuned to your town.
Colorado: planting activity through the year
Last chance in June
Basil (direct sow (spring), by Jun 2) · Bitter Melon (direct sow (spring), by Jun 2) · Cantaloupe / Muskmelon (direct sow (spring), by Jun 2) · Chayote (direct sow (spring), by Jun 2) · Cucamelon (direct sow (spring), by Jun 2) · Cucumber (direct sow (spring), by Jun 2) · Lima Bean (direct sow (spring), by Jun 2) · Luffa (Loofah Gourd) (direct sow (spring), by Jun 2) · Malabar Spinach (direct sow (spring), by Jun 2) · Okra (direct sow (spring), by Jun 2) · Peanut (direct sow (spring), by Jun 2) · Southern Pea (Cowpea) (direct sow (spring), by Jun 2) · Watermelon (direct sow (spring), by Jun 2) · Eggplant (transplant outdoors, by Jun 5) · Ginger (transplant outdoors, by Jun 5) · Sweet Potato (transplant outdoors, by Jun 5) · Turmeric (transplant outdoors, by Jun 5)
Sow or plant outdoors in June (17)
Direct sowing and transplanting windows that fall in June, most urgent first. Windows are one-to-two-week bands around the ideal date.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Basil | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Bitter Melon | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Cantaloupe / Muskmelon | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Chayote | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Cucamelon | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Cucumber | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Lima Bean | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Luffa (Loofah Gourd) | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Malabar Spinach | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Okra | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Peanut | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Southern Pea (Cowpea) | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Watermelon | Direct sow (spring) | May 14 – Jun 2 | Last chance - ends Jun 2 |
| Eggplant | Transplant outdoors | May 19 – Jun 5 | Last chance - ends Jun 5 |
| Ginger | Transplant outdoors | May 19 – Jun 5 | Last chance - ends Jun 5 |
| Sweet Potato | Transplant outdoors | May 19 – Jun 5 | Last chance - ends Jun 5 |
| Turmeric | Transplant outdoors | May 19 – Jun 5 | Last chance - ends Jun 5 |
For fall and winter harvests (8)
Sowings counted back from Colorado's first fall frost, so the crop matures before the cold - or, for garlic and similar, planted after it.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Brussels Sprouts | Start transplants for fall | Jun 1 – Jun 18 | Jun 1 – Jun 18 |
| Rutabaga | Sow for a fall crop | Jun 15 – Jul 2 | Opens Jun 15 |
| Broccoli | Start transplants for fall | Jun 22 – Jul 9 | Opens Jun 22 |
| Cabbage | Start transplants for fall | Jun 22 – Jul 9 | Opens Jun 22 |
| Cauliflower | Start transplants for fall | Jun 22 – Jul 9 | Opens Jun 22 |
| Cucumber | Sow for a fall crop | Jun 29 – Jul 16 | Opens Jun 29 |
| Fennel (Bulb) | Sow for a fall crop | Jun 29 – Jul 16 | Opens Jun 29 |
| Zucchini / Summer Squash | Sow for a fall crop | Jun 29 – Jul 16 | Opens Jun 29 |
Keep sowing (succession)
Repeat sowings of crops already in the ground, for a steady harvest instead of a glut.
- Zucchini / Summer Squash: sow again on Jun 9
- Bush Bean: sow again on Jun 9 and Jun 23
- Lettuce: sow again on Jun 8
- Carrot: sow again on Jun 7
- Radish: sow again on Jun 6
- Sweet Corn: sow again on Jun 9 and Jun 23
- Arugula: sow again on Jun 6
- Turnip: sow again on Jun 9
- Kohlrabi: sow again on Jun 9
- Bok Choy / Pak Choi: sow again on Jun 2
- Mustard Greens: sow again on Jun 9
- Green Onion / Scallion: sow again on Jun 9
- Fennel (Bulb): sow again on Jun 9
- Endive & Escarole: sow again on Jun 2
- Mache (Corn Salad): sow again on Jun 9
- Edamame (Soybean): sow again on Jun 9 and Jun 23
- Sunflower: sow again on Jun 9 and Jun 23
- Rapini (Broccoli Raab): sow again on Jun 9
- Tatsoi: sow again on Jun 6
- Mizuna: sow again on Jun 6
- Amaranth (Leaf): sow again on Jun 9 and Jun 23
- Chervil: sow again on Jun 9
- Watercress: sow again on Jun 2
Harvesting in June
First harvests expected this month from crops sown or planted on time earlier in the season.
Planting dates for popular crops in Colorado
Every crop has its own full-year dates for Colorado: indoor start, transplant or direct sowing, and harvest.
Peak growing season: June garden jobs in Colorado
- Water deeply two or three times a week rather than a little every day - about an inch a week, more in heat. See watering a vegetable garden.
- 15 weeks until the average first frost (October 1). Fall crops start now: brussels sprouts, rutabaga, broccoli, cabbage. See the fall and winter garden guide.
- Check the undersides of leaves twice a week - catching pests early is most of the battle (pest identification guide).
- Harvest often: lettuce, turnip, rapini (broccoli raab), chervil should be coming in. Picking regularly keeps beans, squash and cucumbers producing.
USDA zone chart for Colorado
Colorado spans USDA zones 3b, 4b, 5a, 5b, 6a, 7a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average.
Questions gardeners ask
What vegetables can I plant in Colorado in June?
45 crops have a window in June: basil, bitter melon, cantaloupe / muskmelon, chayote, cucamelon, cucumber, lima bean, luffa (loofah gourd), malabar spinach, okra and more. The tables above give the exact dates for each.
Is it too late to plant tomatoes in Colorado in June?
For this year, yes - the tomato windows in Colorado have closed. The next step is to start seeds indoors from about March 10.
Is it too late to plant lettuce in Colorado in June?
Not too late - it's actually a little early. In Colorado the next lettuce window opens around July 27: sow for a fall crop.
When is the first frost in Colorado?
The statewide average first fall frost is around October 1 and the last spring frost around May 5. Colorado covers a wide range of climates, so local dates can differ by two weeks or more - look yours up by ZIP code.
What can I harvest in Colorado in June?
From plantings made on time: lettuce, turnip, rapini (broccoli raab), chervil, pea, bok choy / pak choi, beet, kohlrabi, kale, cilantro / coriander.
What to plant in June in other states
Dates are computed from Colorado’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.