One of the first steps you take when you are estimating 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.

In Portland you can estimate when to plant ornamental grasses by looking at the USDA zone info.

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.

Ornamental Grasses do ok in moderate cold which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant ornamental grasses in Portland 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 ornamental grasses and expect a good harvest is probably August. Any later than that and your ornamental grasses may not have a chance to really do well. Starting your ornamental grasses indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Portland. It might get as low as 15°F during the coldest months of winter.

Always 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 is different every year. Half of the time in Portland there is a last frost after March 15 so make sure that you are prepared to protect your ornamental grasses if you have a late frost.

USDA Zone Info for Portland

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 Portland

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