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.

A common way of estimating when to plant hollyhocks is to look at the USDA zone info for Waltham.

Planting Calendar for Hollyhocks

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

Hollyhocks are moderately cold tolerant which means that you can plant them a little bit earlier than more sensitive plants.

The earliest that you can plant hollyhocks in Waltham 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 hollyhocks and expect a good harvest is probably September. If you wait any later than that and your hollyhocks may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your hollyhocks indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Waltham. It might get as low as -10°F during the coldest months of winter.

It's important to remember that USDA zone info for Waltham may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Waltham there is a last frost after April 15 so always be ready to cover your hollyhocks in the event of a surprise late frost.

USDA Zone Info for Waltham

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 Waltham

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