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.

The USDA zone info for Irving should be reviewed to figure out when it's possible to plant skullcap.

Planting Calendar for Skullcap

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

Skullcap require warm weather 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 skullcap in Irving 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 skullcap and expect a good harvest is probably August. If you wait any later than that and your skullcap may not have a chance to fully mature. If you are starting your skullcap indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Irving. In the coldest months of winter you should expect an average low temperature of 10°F.

Since the USDA zone info for Irving is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Irving last frost occurs after March 15 so make sure that you are prepared to protect your skullcap in the event of a surprise late frost.

USDA Zone Info for Irving

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 Irving

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