Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Lake Oswego you can figure out when it's possible to plant mimulus by using the USDA zone info.

Planting Calendar for Mimulus

Frost tolerance for mimulus:	Not tolerant of frost.
When to plant:	After the last frost.

Mimulus are not cold tolerant which tells us that it is necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant mimulus 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 mimulus and expect a good harvest is probably August. Any later than that and your mimulus may not have a chance to really do well. Starting your mimulus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Lake Oswego. It might get as low as 15°F during the coldest months of winter.

Keep in mind that USDA zone info for Lake Oswego is just an average and the actual date of last frost is different every year. Since half of the time in Lake Oswego you get a frost after March 15 be ready to cover your mimulus in the event of 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.