One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

You should be able to figure out when it's possible to plant trifolium by looking at the USDA zone info for Pacific.

Planting Calendar for Trifolium

Frost tolerance for trifolium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since trifolium do ok in moderate cold you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant trifolium in Pacific is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant trifolium and expect a good harvest is probably August. Any later than that and your trifolium may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your trifolium indoors.

Last Frost Date

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

Since the USDA zone info for Pacific is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Pacific it frosts late in the year after March 15 be ready to protect your trifolium if you have one of those late frosts.

USDA Zone Info for Pacific

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 Pacific

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