One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when it's the best time to plant celosia is to examine the USDA zone info for Tualatin.

Planting Calendar for Celosia

Frost tolerance for celosia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since celosia are not cold tolerant it is important to wait until after the last frost has passed before you can plant them.

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

Last Frost Date

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

Since the USDA zone info for Tualatin may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Tualatin last frost occurs after March 15 so make sure that you are prepared to protect your celosia if you have one of those late frosts.

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.