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.

The USDA zone info for Marlborough should be reviewed to estimate when to plant calliopsis.

Planting Calendar for Calliopsis

Frost tolerance for calliopsis:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's a bad idea to plant calliopsis until after all chance of frost has passed because they require warm weather.

The earliest that you can plant calliopsis in Marlborough is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant calliopsis and expect a good harvest is probably August. Any later than that and your calliopsis may not have a chance to really do well. You can get started a little bit earlier by starting your calliopsis indoors.

Last Frost Date

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

Since the USDA zone info for Marlborough may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Marlborough it frosts late in the year after April 15 be ready to protect your calliopsis 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.