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.

You will be able to figure out when it's the best time to plant lysimachia by looking at the USDA zone info for Tualatin.

Planting Calendar for Lysimachia

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

Lysimachia do well in mild cold which means that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant lysimachia in Tualatin 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. Any later than that and your lysimachia may not have a chance to grow to maturity. Starting your lysimachia indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Tualatin. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Tualatin is just an average the actual date of last frost is different every year. Since half of the time in Tualatin there is a last frost after March 15 be ready to protect your lysimachia if you have a late frost.

USDA Zone Info for Tualatin

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 Tualatin

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