One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

It's possible to figure out when you can plant ornamental grasses by checking out the USDA zone info for Portland.

Planting Calendar for Ornamental Grasses

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

Since ornamental grasses do ok in moderate cold you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant ornamental grasses 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 ornamental grasses and expect a good harvest is probably September. If you wait any later than that and your ornamental grasses may not have a chance to grow to maturity. Starting your ornamental grasses indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

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 changes from year to year. Since half of the time in Portland you get surprised by a frost after February 15 be ready to cover your ornamental grasses in the event of 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.