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.

In Manhattan you can figure out when to plant trifolium 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.

Trifolium can survive in very little cold which tells us that you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant trifolium in Manhattan 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 fully mature. You can get started a little bit earlier by starting your trifolium indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Manhattan. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Manhattan may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Manhattan it frosts late in the year after April 15 be ready to cover your trifolium in the event of a late frost.

USDA Zone Info for Manhattan

Here is the info for USDA Zone 5b.

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

Plants to Grow in Manhattan

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