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.

The USDA zone info for Rio Grande City should be reffered to in order to figure out when you can plant lithospermum.

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 must wait until after the last frost has passed before you can plant them.

The earliest that you can plant lithospermum in Rio Grande City is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant lithospermum and expect a good harvest is probably September. If you wait any later than that and 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

On average the last frost has passed is on February 15 in Rio Grande City. In the coldest months of winter you can expect an average low temperature of 25°F.

Remember that USDA zone info for Rio Grande City may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Rio Grande City last frost occurs after February 15 so make sure that you are prepared to protect your lithospermum in the event of a late frost.

USDA Zone Info for Rio Grande City

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Rio Grande City

You may be interested in your other planting guides for Rio Grande City.