One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Riverton it's a good idea to estimate when it's a good idea to plant armeria.

Planting Calendar for Armeria

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

Armeria do well in cold which tells us that you can start planting them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant armeria in Riverton 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. You probably don't want to wait any later than that or else your armeria may not have a chance to really do well. If you are starting your armeria indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Riverton is just an average the actual date of last frost is different every year. Half of the time in Riverton you get a frost after May 15 so make sure that you are prepared to protect your armeria if you have a late frost.

USDA Zone Info for Riverton

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 Riverton

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