What to plant in June in Iowa
In Iowa (IA), June is the heart of the growing season - about 7 weeks after the last frost (April 25) and 16 weeks before the first (October 8). The state averages 166 frost-free days a year (last frost April 25, first frost October 8; USDA zones 4b, 5a, 5b).
14 crops have a sowing or planting window this month, including brussels sprouts, rutabaga, broccoli, cabbage, cauliflower.
Dates here come from Iowa frost dates (last frost Apr 25, first frost Oct 8). For one crop in detail, see when to plant broccoli, cabbage or cauliflower in Iowa.
Iowa: planting activity through the year
For fall and winter harvests (5)
Sowings counted back from Iowa'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 8 – Jun 25 | Jun 8 – Jun 25 |
| Rutabaga | Sow for a fall crop | Jun 22 – Jul 9 | Opens Jun 22 |
| Broccoli | Start transplants for fall | Jun 29 – Jul 16 | Opens Jun 29 |
| Cabbage | Start transplants for fall | Jun 29 – Jul 16 | Opens Jun 29 |
| Cauliflower | Start transplants for fall | 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.
- Cucumber: sow again on Jun 20
- Zucchini / Summer Squash: sow again on Jun 27
- Bush Bean: sow again on Jun 13 and Jun 27
- Sweet Corn: sow again on Jun 13 and Jun 27
- Basil: sow again on Jun 20
- Edamame (Soybean): sow again on Jun 13 and Jun 27
- Southern Pea (Cowpea): sow again on Jun 6 and Jun 20
- Sunflower: sow again on Jun 13 and Jun 27
- Amaranth (Leaf): sow again on Jun 13 and Jun 27
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 Iowa
Every crop has its own full-year dates for Iowa: indoor start, transplant or direct sowing, and harvest.
Peak growing season: June garden jobs in Iowa
- 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.
- 16 weeks until the average first frost (October 8). 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 Iowa
Iowa spans USDA zones 4b, 5a, 5b. 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 Iowa in June?
14 crops have a window in June: brussels sprouts, rutabaga, broccoli, cabbage, cauliflower and more. The tables above give the exact dates for each.
Is it too late to plant tomatoes in Iowa in June?
For this year, yes - the tomato windows in Iowa have closed. The next step is to start seeds indoors from about February 28.
Is it too late to plant lettuce in Iowa in June?
Not too late - it's actually a little early. In Iowa the next lettuce window opens around August 3: sow for a fall crop.
When is the first frost in Iowa?
The statewide average first fall frost is around October 8 and the last spring frost around April 25. Your town can be a week or two either side - look yours up by ZIP code.
What can I harvest in Iowa in June?
From plantings made on time: lettuce, turnip, rapini (broccoli raab), chervil, beet, kohlrabi, kale, cilantro / coriander, green onion / scallion, collard greens.
What to plant in June in other states
Dates are computed from Iowa’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.