The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of figuring out when it's a good idea to plant calibrachoa is to examine the USDA zone info for Humboldt.

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.

Since calibrachoa are barely cold tolerant you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant calibrachoa in Humboldt 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 really do well. If you are starting your calibrachoa 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 Humboldt. In the coldest months of winter you can expect an average low temperature of 0°F.

Since the USDA zone info for Humboldt is an average the actual date of last frost is different every year. Half of the time in Humboldt you get surprised by a frost after April 15 so make sure that you are ready to protect your calibrachoa in the event of a surprise late frost.

USDA Zone Info for Humboldt

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Humboldt

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