Before planting it is a good idea to find your USDA Zone info to estimate 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.

A way of determining when you can plant armeria is to use the USDA zone info for Billings.

Planting Calendar for Armeria

Frost tolerance for armeria:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

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

The earliest that you can plant armeria in Billings 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 armeria and expect a good harvest is probably August. Any later than that and your armeria may not have a chance to really do well. You can get started a little bit earlier by starting your armeria indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Billings. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Billings may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Billings it frosts late in the year after May 15 so just be sure to be ready to protect your armeria if you have a late frost.

USDA Zone Info for Billings

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 Billings

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