One of the first steps you take when you are determining 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 common way of estimating when you can plant calibrachoa is to look at the USDA zone info for Corvallis.

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 plant them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant calibrachoa in Corvallis 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. Any later than that and your calibrachoa may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your calibrachoa indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Corvallis. In the coldest months of winter you can expect an average low temperature of 15°F.

It's important to remember that USDA zone info for Corvallis may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Corvallis last frost occurs after March 15 so make sure that you are prepared to protect your calibrachoa in the event of a surprise late frost.

USDA Zone Info for Corvallis

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Corvallis

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