When to Plant Mimulus in Watertown, MA

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 Watertown can be read to figure out when it's possible to plant mimulus.


Planting Calendar for Mimulus

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

It's probably not a good idea to plant mimulus until after all chance of frost has passed because they require warm weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant mimulus
Possibly ok, but a risky time to plant mimulus
Probably not a good time to plant mimulus

The earliest that you can plant mimulus in Watertown 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. If you are starting your mimulus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Watertown. In the coldest months of winter you should expect an average low temperature of -5°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Watertown and it will vary from year to year. Half of the time in Watertown you get surprised by a frost after April 15 so just be sure to be ready to cover your mimulus in the event of a late frost.

USDA Zone Info for Watertown

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 Low0°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 Watertown

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