One of the first steps you take when you are figuring out 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 should be able to estimate when to plant mimulus by using the USDA zone info for Haverhill.

Planting Calendar for Mimulus

Frost tolerance for mimulus:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since mimulus are not cold tolerant it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant mimulus in Haverhill 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 mimulus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your mimulus may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your mimulus indoors.

Last Frost Date

On average the last frost is on April 15 in Haverhill. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Haverhill is not always accurate the actual date of last frost changes from year to year. Half of the time in Haverhill you get a frost after April 15 so make sure that you are ready to cover your mimulus if you have one of those late frosts.

USDA Zone Info for Haverhill

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 Haverhill

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