When to Plant Pyrethrum in Zone 3b

One of the best tools that you have as gardeners to help us figure out 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 looking at the USDA zone info for Zone 3b you will be able to figure out when you can 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 just a bit earlier in the year because they are moderately cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant pyrethrum
Possibly ok, but a risky time to plant pyrethrum
Probably not a good time to plant pyrethrum

The earliest that you can plant pyrethrum in Zone 3b 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. If you wait any later than that and your pyrethrum may not have a chance to grow to maturity. Starting your pyrethrum indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Zone 3b the average date of last frost happens on May 15. You should expect an average low temperature of -35°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Zone 3b and it is different every year. Since half of the time in Zone 3b there is a last frost after May 15 be ready to protect your pyrethrum in the event of a surprise late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-35°F
Highest Expected Low-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in your other planting guides for Zone 3b.