One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Richland it's a good idea to estimate when it's the best time to plant pyrethrum.

Planting Calendar for Pyrethrum

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

You can plant pyrethrum a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant pyrethrum in Richland 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 pyrethrum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your pyrethrum may not have a chance to really do well. Starting your pyrethrum indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Richland. You can expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Richland is just an average the actual date of last frost changes from year to year. Since half of the time in Richland it frosts late in the year after March 15 be ready to protect your pyrethrum if you have a surprise late frost.

USDA Zone Info for Richland

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Richland

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