One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Mattoon can be used to determine when it's the best time to plant browallia.

Planting Calendar for Browallia

Frost tolerance for browallia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Browallia are not cold tolerant which tells us that you have to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant browallia in Mattoon is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant browallia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your browallia may not have a chance to grow to maturity. If you are starting your browallia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Mattoon. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Mattoon may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Mattoon it frosts late in the year after April 15 be ready to protect your browallia in the event of one of those late frosts.

USDA Zone Info for Mattoon

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Mattoon

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