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When to Plant Peonies in Rock Springs, WY

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.

You can determine when you can plant peonies in Rock Springs by looking at the USDA zone info.


Planting Calendar for Peonies

Frost tolerance for peonies: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Peonies are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can plant them slightly earlier than other plants that might not handle the cold.

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

The earliest that you can plant peonies in Rock Springs 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 peonies and expect a good harvest is probably August. You probably don't want to wait any later than that or else your peonies may not have a chance to really do well. Starting your peonies indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Rock Springs the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Rock Springs and it can change quite a bit from year to year. Since half of the time in Rock Springs there is a last frost after April 15 be ready to cover your peonies if you have a surprise late frost.

USDA Zone Info for Rock Springs

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 Rock Springs

You may be interested in your other planting guides for Rock Springs.