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

A way of making a decision about when to plant penstemon is to examine the USDA zone info for Winooski.

Planting Calendar for Penstemon

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

Penstemon tend to make it in a little bit of cold which tells us that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant penstemon in Winooski 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. Any later than that and your penstemon may not have a chance to really do well. 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

The average date of last frost is April 15 in Winooski. You should expect an average low temperature of -20°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Winooski is just an average and the actual date of last frost changes from year to year. Half of the time in Winooski you get a frost after April 15 so be sure to be ready to protect your penstemon if you have a surprise late frost.

USDA Zone Info for Winooski

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°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 -15°F.

Plants to Grow in Winooski

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