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.

A common way of making a decision about when it's a good idea to plant helianthemum is to check out the USDA zone info for Woodburn.

Planting Calendar for Helianthemum

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

You can plant helianthemum just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant helianthemum in Woodburn 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. If you wait 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 March 15 in Woodburn. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Woodburn and it is different every year. Half of the time in Woodburn last frost occurs after March 15 so make sure that you are prepared to cover your helianthemum in the event of a late frost.

USDA Zone Info for Woodburn

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 Woodburn

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