Before planting it is a good idea to find your USDA Zone info to determine 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.

A common way of getting a good idea when it's a good idea to plant helianthemum is to look at the USDA zone info for Prineville.

Planting Calendar for Helianthemum

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

Helianthemum do well in moderate cold which tells us that you can plant them earlier than more sensitive plants.

The earliest that you can plant helianthemum in Prineville 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 helianthemum and expect a good harvest is probably September. Any later than that and your helianthemum may not have a chance to grow to maturity. Starting your helianthemum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Prineville. In the coldest months of winter you should expect an average low temperature of -5°F.

Remember that USDA zone info for Prineville 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 Prineville you get a frost after April 15 so make sure that you are prepared to cover your helianthemum if you have a surprise late frost.

USDA Zone Info for Prineville

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Prineville

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