Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Riverdale you can figure out when it's the best time 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.

Lithospermum are not cold tolerant which means that you really should wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant lithospermum in Riverdale 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. Any later than that and your lithospermum may not have a chance to fully mature. Starting your lithospermum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Riverdale. It might get as low as 10°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Riverdale and it can change quite a bit from year to year. Since half of the time in Riverdale it frosts late in the year after March 15 be ready to cover your lithospermum if you have one of those late frosts.

USDA Zone Info for Riverdale

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Riverdale

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