One of the best tools that you have as gardeners to help us figure out 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.

One way of figuring out when it's a good idea to plant trifolium is to consult the USDA zone info for Hillsborough.

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 one of those plants that can tolerate a tiny bit of cold weather you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant trifolium in Hillsborough 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 little bit earlier by starting your trifolium indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Hillsborough. You can expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Hillsborough may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Hillsborough you get a frost after April 15 be ready to protect your trifolium in the event of a late frost.

USDA Zone Info for Hillsborough

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Hillsborough

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