The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant osteospermum in Lake Oswego can be figured out by referring to the USDA zone info.

Planting Calendar for Osteospermum

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

Osteospermum do well in moderate cold which means that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant osteospermum 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 osteospermum and expect a good harvest is probably September. Any later than that and your osteospermum may not have a chance to fully mature. Starting your osteospermum indoors is a great way to get them started a few 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.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Lake Oswego and it can change quite a bit 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 osteospermum 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.