One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to figure out when it's possible to plant broccoli by looking at the USDA zone info for Ottumwa.

Planting Calendar for Broccoli

Frost tolerance for broccoli:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Broccoli tend to make it in a little bit of cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant broccoli in Ottumwa is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant broccoli and expect a good harvest is probably September. Any later than that and your broccoli may not have a chance to fully mature. If you are starting your broccoli indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Ottumwa. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Ottumwa is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Ottumwa you get surprised by a frost after April 15 so always be ready to cover your broccoli if you have one of those late frosts.

USDA Zone Info for Ottumwa

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Ottumwa

You may be interested in your other planting guides for Ottumwa.