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

It's possible to figure out when it's possible to plant violas by checking out the USDA zone info for Sterling.

Planting Calendar for Violas

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

Violas tend to make it in pretty solid cold which means that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant violas in Sterling 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 violas and expect a good harvest is probably September. If you wait any later than that and your violas may not have a chance to grow to maturity. If you are starting your violas indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Sterling. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Sterling may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Sterling you get a frost after April 15 be ready to protect your violas if you have a late frost.

USDA Zone Info for Sterling

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 Sterling

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