One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to figure out when it's a good idea to plant canna by referring to the USDA zone info for Lake Oswego.

Planting Calendar for Canna

Frost tolerance for canna:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant canna until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant canna in Lake Oswego is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant canna and expect a good harvest is probably August. If you wait any later than that and your canna may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your canna indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Lake Oswego. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Lake Oswego may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Lake Oswego it frosts late in the year after March 15 so make sure that you are prepared to protect your canna in the event of 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.