One of the best tools that you have as gardeners to help us estimate 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.

It's possible to figure out when you can plant calibrachoa by using the USDA zone info for Lake Oswego.

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 can survive in mild cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant calibrachoa in Lake Oswego 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. You probably don't want to wait any later than that or else your calibrachoa may not have a chance to really do well. You can get started a few weeks earlier by starting your calibrachoa indoors.

Last Frost Date

In Lake Oswego the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 15°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Lake Oswego and it changes from year to year. Since half of the time in Lake Oswego you get surprised by a frost after March 15 be ready to cover your calibrachoa if you have a surprise late frost.

USDA Zone Info for Lake Oswego

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 Lake Oswego

You may be interested in your other planting guides for Lake Oswego.