The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Rocky River it's a good idea to determine when it's a good idea 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.

You can plant penstemon just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant penstemon in Rocky River 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. You probably don't want to wait any later than that or else your penstemon may not have a chance to grow to maturity. If you are starting your penstemon indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Rocky River. In the coldest months of winter you can expect an average low temperature of -5°F.

Always keep in mind that USDA zone info for Rocky River is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Rocky River you get surprised by a frost after April 15 be ready to cover your penstemon in the event of a late frost.

USDA Zone Info for Rocky River

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Rocky River

You may be interested in your other planting guides for Rocky River.