One of the first steps you take when you are estimating 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.

You can determine when it's possible to plant penstemon in Marlborough by reviewing 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.

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 Marlborough 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

The average date of last frost is April 15 in Marlborough. In the coldest months of winter you can expect an average low temperature of -10°F.

Just be sure to remember that USDA zone info for Marlborough is just an average and the actual date of last frost will vary from year to year. Half of the time in Marlborough it frosts late in the year after April 15 so make sure that you are ready to protect your penstemon if you have a late frost.

USDA Zone Info for Marlborough

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 Marlborough

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