The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Johnston you can figure out when it's possible to plant armeria by referring to the USDA zone info.

Planting Calendar for Armeria

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

Armeria are very cold tolerant which means that you can plant them much earlier than other plants that might not handle the cold.

The earliest that you can plant armeria in Johnston 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 armeria and expect a good harvest is probably September. If you wait any later than that and your armeria may not have a chance to really do well. Starting your armeria 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 April 15 in Johnston. In the coldest months of winter you should expect an average low temperature of -20°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Johnston and it is different every year. Since half of the time in Johnston it frosts late in the year after April 15 be ready to cover your armeria in the event of a late frost.

USDA Zone Info for Johnston

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Johnston

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