One of the first steps you take when you are estimating 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.

The earliest that you can plant pyrethrum in Watertown can be figured out by reviewing the USDA zone info.

Planting Calendar for Pyrethrum

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

Pyrethrum tend to make it in some cold which means that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant pyrethrum 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 pyrethrum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your pyrethrum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your pyrethrum indoors.

Last Frost Date

The average date of last frost is May 15 in Watertown. You should expect an average low temperature of -25°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Watertown and it is different every year. Half of the time in Watertown it frosts late in the year after May 15 so make sure that you are ready to cover your pyrethrum in the event of a late frost.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Watertown

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