Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant angel's trumpets in Portland should be figured out by checking out the USDA zone info.

Planting Calendar for Angel's Trumpets

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

Angel's Trumpets are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant angel's trumpets 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 angel's trumpets and expect a good harvest is probably August. If you wait any later than that and your angel's trumpets may not have a chance to really do well. You can get started a couple of weeks earlier by starting your angel's trumpets indoors.

Last Frost Date

In Portland the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Portland is an average the actual date of last frost will vary from year to year. Half of the time in Portland it frosts late in the year after April 15 so make sure that you are prepared to protect your angel's trumpets if you have 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.