One of the first steps you take when you are estimating 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.

It's a good idea to figure out when to plant radishes by checking out the USDA zone info for Mercer Island.

Planting Calendar for Radishes

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

You can plant radishes earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant radishes in Mercer Island 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 fully mature. 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

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

Since the USDA zone info for Mercer Island is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Mercer Island you get surprised by a frost after March 15 be ready to cover your radishes in the event of a surprise late frost.

USDA Zone Info for Mercer Island

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Mercer Island

You may be interested in your other planting guides for Mercer Island.