One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 Sterling it's a good idea to determine when it's the best time to plant purple bell vines.

Planting Calendar for Purple Bell Vines

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

Purple Bell Vines are barely cold tolerant which means that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant purple bell vines in Sterling 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 purple bell vines and expect a good harvest is probably August. If you wait any later than that and your purple bell vines may not have a chance to fully mature. Starting your purple bell vines indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Sterling is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Sterling you get a frost after April 15 so be sure to be ready to cover your purple bell vines if you have one of those late frosts.

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.