One of the first steps you take when you are making a decision about 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.

The first chance to plant tropical water plants in Portland can be figured out by looking at the USDA zone info.

Planting Calendar for Tropical Water Plants

Frost tolerance for tropical water plants:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Tropical Water Plants do not do well in cold weather which tells us that it's necessary 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 tropical water plants 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 tropical water plants and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tropical water plants may not have a chance to really do well. Starting your tropical water plants indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Portland may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Portland last frost occurs after April 15 so just be sure to be ready to cover your tropical water plants if you have a 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.