One of the first steps you take when you are determining your gardening schedule is find your 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 Warwick should be used to figure out when it's the best time to plant penstemon.

Planting Calendar for Penstemon

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

Penstemon do ok in moderate cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant penstemon in Warwick 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 couple of weeks earlier.

Last Frost Date

In Warwick the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Warwick is just an average and the actual date of last frost is different every year. Half of the time in Warwick you get a frost after April 15 so make sure that you are prepared to cover your penstemon if you have a surprise late frost.

USDA Zone Info for Warwick

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Warwick

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