One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's possible to plant penstemon in Mckinney by looking at the USDA zone info.

Planting Calendar for Penstemon

Frost tolerance for penstemon:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since penstemon do well in moderate cold you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant penstemon in Mckinney 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 penstemon and expect a good harvest is probably September. If you wait any later than that and your penstemon may not have a chance to grow to maturity. Starting your penstemon indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Mckinney. You can expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Mckinney is just an average the actual date of last frost changes from year to year. Half of the time in Mckinney there is a last frost after March 15 so make sure that you are prepared to cover your penstemon if you have a surprise late frost.

USDA Zone Info for Mckinney

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 Mckinney

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