One of the first steps you take when you are figuring out 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.

By reviewing the USDA zone info for Washington it's a good idea to determine when it's a good idea to plant tropical water plants.

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.

It's probably a bad idea to plant tropical water plants until after all chance of frost has passed because they require warm weather.

The earliest that you can plant tropical water plants in Washington 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 grow to maturity. If you are starting your tropical water plants indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Washington. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that USDA zone info for Washington is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Washington you get surprised by a frost after April 15 be ready to cover your tropical water plants in the event of a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Washington

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