One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when it's a good idea to plant calibrachoa is to use the USDA zone info for Zone 1b.

Planting Calendar for Calibrachoa

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

You can plant calibrachoa just a tiny bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant calibrachoa in Zone 1b is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant calibrachoa and expect a good harvest is probably July. You probably don't want to wait any later than that or else your calibrachoa may not have a chance to grow to maturity. If you are starting your calibrachoa indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is June 15 in Zone 1b. It might get as low as -55°F during the coldest months of winter.

Since the USDA zone info for Zone 1b is just an average the actual date of last frost will vary from year to year. Half of the time in Zone 1b it frosts late in the year after June 15 so just be sure to be ready to cover your calibrachoa in the event of one of those late frosts.

USDA Zone Info for Zone 1b

Here is the info for USDA Zone 1b.

Average Date of Last Frost (spring)	June 15
Average Date of First Frost (fall)	July 15
Lowest Expected Low	-55°F
Highest Expected Low	-50°F

This means that on a really cold year, the coldest it will get is -55°F. On most years you should be prepared to experience lows near -50°F.

Plants to Grow in Zone 1b

You may be interested in your other planting guides for Zone 1b.