Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Manassas can be reffered to in order to estimate when it's possible to plant trifolium.

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 a bit earlier in the year than more sensitive plants.

The earliest that you can plant trifolium in Manassas 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 really do well. Starting your trifolium indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Manassas. You can expect an average low temperature of 0°F in the coldest months of winter.

Always keep in mind that USDA zone info for Manassas may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Manassas there is a last frost after April 15 be ready to cover your trifolium in the event of a late frost.

USDA Zone Info for Manassas

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Manassas

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