One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of figuring out when it's the best time to plant roses is to examine the USDA zone info for Portland.

Planting Calendar for Roses

Frost tolerance for roses:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since roses are one of those plants that can tolerate a little bit of cold weather you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant roses 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 roses and expect a good harvest is probably September. If you wait any later than that and your roses may not have a chance to really do well. If you are starting your roses indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Portland. It might get as low as -15°F during the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Portland and it can change quite a bit 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 ready to protect your roses 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.