One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Manhattan you should be able to figure out when it's a good idea to plant radicchio.

Planting Calendar for Radicchio

Frost tolerance for radicchio:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Radicchio do well in mild cold which means that you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant radicchio in Manhattan 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 radicchio and expect a good harvest is probably September. Any later than that and your radicchio may not have a chance to really do well. If you are starting your radicchio indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Manhattan the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Manhattan is not always accurate 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 protect your radicchio in the event of a surprise 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.