Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant calibrachoa in Zone 6a should be figured out by using the USDA zone info.

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.

Calibrachoa do ok in moderate cold which tells us that you can get them planted just a bit earlier than other plants that might not handle the cold.

The earliest that you can plant calibrachoa in Zone 6a 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 calibrachoa and expect a good harvest is probably August. If you wait any later than that and your calibrachoa may not have a chance to fully mature. You can get started a little bit earlier by starting your calibrachoa indoors.

Last Frost Date

On average the last frost is on April 15 in Zone 6a. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Zone 6a may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Zone 6a it frosts late in the year after April 15 be ready to protect your calibrachoa if you have a late frost.

USDA Zone Info for Zone 6a

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Zone 6a

You may be interested in your other planting guides for Zone 6a.