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

By looking at the USDA zone info for Mount Vernon it's possible to estimate when it's a good idea to plant osteospermum.

Planting Calendar for Osteospermum

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

Since osteospermum are moderately cold tolerant 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 Mount Vernon 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 really do well. You can get started a little bit earlier by starting your osteospermum indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Mount Vernon. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Mount Vernon may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Mount Vernon there is a last frost after April 15 be ready to protect your osteospermum in the event of a late frost.

USDA Zone Info for Mount Vernon

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Mount Vernon

You may be interested in your other planting guides for Mount Vernon.