Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when you can plant feverfew in Helena by checking out the USDA zone info.

Planting Calendar for Feverfew

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

Feverfew can survive in a little bit of cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant feverfew in Helena 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 feverfew and expect a good harvest is probably August. Any later than that and your feverfew may not have a chance to fully mature. If you are starting your feverfew indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Helena. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Helena and it can change quite a bit from year to year. Half of the time in Helena it frosts late in the year after May 15 so just be sure to be ready to protect your feverfew if you have a late frost.

USDA Zone Info for Helena

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 Helena

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