One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

A common way of making a decision about when to plant xerianthemum is to use the USDA zone info for Portland.

Planting Calendar for Xerianthemum

Frost tolerance for xerianthemum:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant xerianthemum a bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant xerianthemum in Portland 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 xerianthemum and expect a good harvest is probably September. If you wait any later than that and your xerianthemum may not have a chance to fully mature. Starting your xerianthemum indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Portland. In the coldest months of winter you should expect an average low temperature of 25°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portland and it can change quite a bit from year to year. Since half of the time in Portland you get a frost after February 15 be ready to cover your xerianthemum if you have a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

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

Plants to Grow in Portland

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