Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant osteospermum in Portsmouth can be determined by looking at 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.

Since osteospermum are one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant osteospermum in Portsmouth 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 few weeks earlier by starting your osteospermum indoors.

Last Frost Date

The average date of last frost is March 15 in Portsmouth. It might get as low as 10°F during the coldest months of winter.

Keep in mind that USDA zone info for Portsmouth is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Portsmouth you get a frost after March 15 be ready to protect your osteospermum if you have one of those late frosts.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Portsmouth

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