One of the best tools that you have as gardeners to help us determine 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.

You will be able to determine when you can plant scabiosa by looking at the USDA zone info for Waltham.

Planting Calendar for Scabiosa

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

Since scabiosa do well in moderate cold you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant scabiosa 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 scabiosa and expect a good harvest is probably September. If you wait any later than that and your scabiosa may not have a chance to grow to maturity. If you are starting your scabiosa indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Waltham is an average and the actual date of last frost changes 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 scabiosa if you have one of those late frosts.

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.