One of the first steps you take when you are determining your gardening schedule is find your 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 estimate when you can plant purple coneflower by looking at the USDA zone info for Watertown.

Planting Calendar for Purple Coneflower

Frost tolerance for purple coneflower:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Purple Coneflower do ok in very little cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant purple coneflower in Watertown is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant purple coneflower and expect a good harvest is probably August. If you wait any later than that and your purple coneflower may not have a chance to grow to maturity. Starting your purple coneflower indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Watertown and it can change quite a bit from year to year. Since half of the time in Watertown it frosts late in the year after April 15 be ready to cover your purple coneflower in the event of a surprise 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 Low	0°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.