One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Astoria you can determine when to plant osteospermum by using 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 tend to make it in a little bit of cold which tells us 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 Astoria 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. You probably don't want to wait any later than that or else your osteospermum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your osteospermum indoors.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Astoria and it is different every year. Half of the time in Astoria it frosts late in the year after March 15 so just be sure to be ready to cover your osteospermum if you have one of those late frosts.

USDA Zone Info for Astoria

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 Astoria

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