One of the first steps you take when you are estimating 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.

In Lake Oswego you can estimate when it's the best time to plant lysimachia by reviewing the USDA zone info.

Planting Calendar for Lysimachia

Frost tolerance for lysimachia:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since lysimachia do well in moderate cold you can plant them a little bit earlier in the year than other plants that might not handle the cold.

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

The last month that you can plant lysimachia and expect a good harvest is probably September. If you wait any later than that and your lysimachia may not have a chance to fully mature. Starting your lysimachia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Lake Oswego. In the coldest months of winter you should 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 is different every year. Half of the time in Lake Oswego you get surprised by a frost after March 15 so just be sure to be ready to protect your lysimachia if you have one of those late frosts.

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.