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 determining when it's the best time to plant celosia is to check out the USDA zone info for Waltham.

Planting Calendar for Celosia

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

It's probably a bad idea to plant celosia until after all chance of frost has passed because they are not cold tolerant.

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

Last Frost Date

In Waltham the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Waltham may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Waltham last frost occurs after April 15 be ready to cover your celosia if you have a 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.