One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant trifolium in Zone 9b can be determined by using the USDA zone info.

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 are barely cold tolerant you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant trifolium in Zone 9b is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant trifolium and expect a good harvest is probably September. Any later than that and your trifolium may not have a chance to grow to maturity. If you are starting your trifolium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Zone 9b. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Zone 9b is an average the actual date of last frost will vary from year to year. Since half of the time in Zone 9b it frosts late in the year after February 15 be ready to cover your trifolium in the event of a surprise late frost.

USDA Zone Info for Zone 9b

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Zone 9b

You may be interested in your other planting guides for Zone 9b.