One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Portland you can figure out when it's possible to plant polka dot plant by reviewing the USDA zone info.

Planting Calendar for Polka Dot Plant

Frost tolerance for polka dot plant:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Polka Dot Plant require warm weather which tells us that you have to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant polka dot plant in Portland is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant polka dot plant and expect a good harvest is probably August. You probably don't want to wait any later than that or else your polka dot plant may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your polka dot plant indoors.

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.

Just be sure to remember 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 will vary from year to year. Since half of the time in Portland you get a frost after April 15 be ready to protect your polka dot plant if you have a surprise late frost.

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.