One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when it's the best time to plant browallia is to examine the USDA zone info for Hillsborough.

Planting Calendar for Browallia

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

Since browallia do not do well in cold weather you need to wait until after the last frost before you can plant them.

The earliest that you can plant browallia in Hillsborough 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. If you wait any later than that and your browallia may not have a chance to fully mature. If you are starting your browallia 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 Hillsborough. In the coldest months of winter you should expect an average low temperature of 5°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Hillsborough and it will vary from year to year. Half of the time in Hillsborough last frost occurs after April 15 so make sure that you are prepared to protect your browallia if you have a surprise late frost.

USDA Zone Info for Hillsborough

Here is the info for USDA Zone 7b.

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

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

Plants to Grow in Hillsborough

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