One of the first steps you take when you are getting a good idea 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 referring to the USDA zone info for Tualatin it's a good idea to figure out when 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.

You can not plant tropical water plants until after the last frost because they do not do well in cold weather.

The earliest that you can plant tropical water plants in Tualatin 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. Any later than that and your tropical water plants may not have a chance to grow to maturity. You can get started a little bit earlier by starting your tropical water plants indoors.

Last Frost Date

In Tualatin the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Tualatin is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Tualatin it frosts late in the year after March 15 so just be sure to be ready to protect your tropical water plants in the event of a late frost.

USDA Zone Info for Tualatin

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Tualatin

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