One of the first steps you take when you are figuring out 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 the best time to plant trifolium by using the USDA zone info for Zone 6a.

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.

You can plant trifolium just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant trifolium in Zone 6a 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. If you wait any later than that and your trifolium may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your trifolium indoors.

Last Frost Date

The average date of last frost is April 15 in Zone 6a. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Zone 6a is just an average the actual date of last frost will vary from year to year. Since half of the time in Zone 6a there is a last frost after April 15 be ready to protect your trifolium if you have a surprise late frost.

USDA Zone Info for Zone 6a

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 Zone 6a

You may be interested in your other planting guides for Zone 6a.