One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Seattle you will be able to estimate when it's the best time to plant carrots.

Planting Calendar for Carrots

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

You can plant carrots a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant carrots in Seattle 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 carrots and expect a good harvest is probably September. You probably don't want to wait any later than that or else your carrots may not have a chance to grow to maturity. If you are starting your carrots indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Seattle the average date of last frost happens on March 15. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Seattle is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Seattle last frost occurs after March 15 be ready to protect your carrots if you have one of those late frosts.

USDA Zone Info for Seattle

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 Seattle

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