One of the first steps you take when you are figuring out 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.

The USDA zone info for Alton should be reviewed to estimate when it's possible to plant browallia.

Planting Calendar for Browallia

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

It's a bad idea to plant browallia until after the last frost because they do not do well in cold weather.

The earliest that you can plant browallia in Alton 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. Any later than that and your browallia may not have a chance to really do well. Starting your browallia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Alton. You can expect an average low temperature of -10°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Alton and it is different every year. Half of the time in Alton you get a frost after April 15 so be sure to be ready to cover your browallia if you have one of those late frosts.

USDA Zone Info for Alton

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 Alton

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