One of the first steps you take when you are getting a good idea 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.

A common way of getting a good idea when it's a good idea to plant lithospermum is to look at the USDA zone info for Hillsboro.

Planting Calendar for Lithospermum

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

Lithospermum are not cold tolerant which tells us that it's necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant lithospermum in Hillsboro 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 really do well. If you are starting your lithospermum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Hillsboro the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that USDA zone info for Hillsboro is an average and the actual date of last frost will vary from year to year. Since half of the time in Hillsboro it frosts late in the year after March 15 be ready to cover your lithospermum in the event of one of those late frosts.

USDA Zone Info for Hillsboro

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Hillsboro

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