When to Plant Snow-in Summer in Castle Rock, CO

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.

You can determine when it's the best time to plant snow-in summer in Castle Rock by using the USDA zone info.


Planting Calendar for Snow-in Summer

Frost tolerance for snow-in summer: Tolerant of some frost.
When to plant: Up to 5 weeks before last frost.

Snow-in Summer are one of those plants that can tolerate a little bit of cold weather which means that you can plant them earlier than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant snow-in summer
Possibly ok, but a risky time to plant snow-in summer
Probably not a good time to plant snow-in summer

The earliest that you can plant snow-in summer in Castle Rock 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 snow-in summer and expect a good harvest is probably September. Any later than that and your snow-in summer may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your snow-in summer indoors.

Last Frost Date

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

Since the USDA zone info for Castle Rock is an average the actual date of last frost changes from year to year. Since half of the time in Castle Rock last frost occurs after April 15 be ready to protect your snow-in summer if you have one of those late frosts.

USDA Zone Info for Castle Rock

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Castle Rock

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