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

In Berwyn you can figure out when to plant lithospermum by checking out the USDA zone info.

Planting Calendar for Lithospermum

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

You should not plant lithospermum until after the last frost because they do not do well in cold weather.

The earliest that you can plant lithospermum in Berwyn 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 lithospermum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your lithospermum may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your lithospermum indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Berwyn. You should expect an average low temperature of -10°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Berwyn and it can change quite a bit from year to year. Half of the time in Berwyn you get surprised by a frost after April 15 so make sure that you are prepared to cover your lithospermum if you have one of those late frosts.

USDA Zone Info for Berwyn

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 Berwyn

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