When to Plant Broccoli in Ottawa, IL

One of the first steps you take when you are estimating 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 possible to estimate when it's a good idea to plant broccoli by using the USDA zone info for Ottawa.


Planting Calendar for Broccoli

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

You can plant broccoli a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant broccoli
Possibly ok, but a risky time to plant broccoli
Probably not a good time to plant broccoli

The earliest that you can plant broccoli in Ottawa 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. If you wait any later than that and your broccoli may not have a chance to really do well. If you are starting your broccoli indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Ottawa. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Ottawa and it changes from year to year. Since half of the time in Ottawa it frosts late in the year after April 15 be ready to protect your broccoli in the event of a surprise late frost.

USDA Zone Info for Ottawa

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 Ottawa

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