The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Longmont you can determine when it's a good idea to plant black radish by reviewing the USDA zone info.

Planting Calendar for Black radish

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

Black radish are moderately cold tolerant which tells us that you can plant them earlier than other frost tender plants.

The earliest that you can plant black radish in Longmont 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 black radish and expect a good harvest is probably September. You probably don't want to wait any later than that or else your black radish may not have a chance to fully mature. You can get started a little bit earlier by starting your black radish indoors.

Last Frost Date

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

Since the USDA zone info for Longmont is just an average the actual date of last frost changes from year to year. Half of the time in Longmont it frosts late in the year after April 15 so just be sure to be ready to protect your black radish if you have a surprise late frost.

USDA Zone Info for Longmont

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 Longmont

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