Before planting it is a good idea to find your USDA Zone info to estimate 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.

A common way of figuring out when it's possible to plant radishes is to look at the USDA zone info for Ambler.

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 quite a bit of cold which tells us that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant radishes in Ambler 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. Any later than that and your radishes may not have a chance to grow to maturity. If you are starting your radishes indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Ambler is just an average the actual date of last frost changes from year to year. Half of the time in Ambler last frost occurs after April 15 so always be ready to cover your radishes if you have a late frost.

USDA Zone Info for Ambler

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 Ambler

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