One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

The USDA zone info for Presidio can be looked at to estimate when it's the best time to plant bittercress.

Planting Calendar for Bittercress

Frost tolerance for bittercress:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant bittercress just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant bittercress in Presidio is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant bittercress and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bittercress may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your bittercress indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Presidio. In the coldest months of winter you can expect an average low temperature of 20°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Presidio and it is different every year. Since half of the time in Presidio there is a last frost after February 15 be ready to cover your bittercress in the event of a late frost.

USDA Zone Info for Presidio

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Presidio

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