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

In Silverton you can determine when it's the best time to plant pyrethrum by using 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 do well in moderate cold which means that you can plant them a little bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant pyrethrum in Silverton 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. If you wait any later than that and your pyrethrum may not have a chance to really do well. Starting your pyrethrum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Silverton. You can expect an average low temperature of 10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Silverton is not always accurate and the actual date of last frost changes from year to year. Half of the time in Silverton there is a last frost after March 15 so make sure that you are ready to cover your pyrethrum in the event of a surprise late frost.

USDA Zone Info for Silverton

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 Silverton

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