The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Portland you will be able to estimate when to plant pennisetum.

Planting Calendar for Pennisetum

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

Pennisetum are barely cold tolerant which means that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant pennisetum 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 pennisetum and expect a good harvest is probably August. Any later than that and your pennisetum may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your pennisetum indoors.

Last Frost Date

The average date of last frost is April 15 in Portland. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that USDA zone info for Portland is an average and the actual date of last frost changes from year to year. Since half of the time in Portland you get surprised by a frost after April 15 be ready to protect your pennisetum in the event of one of those late frosts.

USDA Zone Info for Portland

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Portland

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