One of the first steps you take when you are determining 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.

In Oswego you can estimate when to plant lithospermum by using the USDA zone info.

Planting Calendar for Lithospermum

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

Since lithospermum are not cold tolerant you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant lithospermum in Oswego 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. If you wait any later than that and your lithospermum may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your lithospermum indoors.

Last Frost Date

The average date of last frost is April 15 in Oswego. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Oswego is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Oswego you get a frost after April 15 be ready to protect your lithospermum if you have a surprise late frost.

USDA Zone Info for Oswego

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 Oswego

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