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

The USDA zone info for Lake Oswego should be used to figure out when it's possible to plant alstromeria.

Planting Calendar for Alstromeria

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

Since alstromeria are moderately cold tolerant you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant alstromeria 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 alstromeria and expect a good harvest is probably September. Any later than that and your alstromeria may not have a chance to grow to maturity. Starting your alstromeria indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Lake Oswego. In the coldest months of winter you can expect an average low temperature of 15°F.

Just be sure to remember 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 it frosts late in the year after March 15 be ready to protect your alstromeria 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.