One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant radishes in South Portland should be estimated by referring to the USDA zone info.

Planting Calendar for Radishes

Frost tolerance for radishes:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Radishes do ok in cold weather which means that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant radishes in South Portland 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 radishes and expect a good harvest is probably September. If you wait any later than that and your radishes may not have a chance to grow to maturity. Starting your radishes indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in South Portland. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for South Portland is an average the actual date of last frost changes from year to year. Half of the time in South Portland it frosts late in the year after April 15 so be sure to be ready to cover your radishes in the event of a late frost.

USDA Zone Info for South Portland

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 South Portland

You may be interested in your other planting guides for South Portland.