Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant osteospermum in Havre should be estimated 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.

You can plant osteospermum a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant osteospermum in Havre is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant osteospermum and expect a good harvest is probably August. If you wait any later than that and your osteospermum may not have a chance to fully mature. If you are starting your osteospermum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Havre. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Havre is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Havre you get surprised by a frost after May 15 so make sure that you are prepared to cover your osteospermum if you have a late frost.

USDA Zone Info for Havre

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Havre

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