The USDA Zone info is a great tool for gardeners to help us determine 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.

One way of making a decision about when to plant marigold is to check out the USDA zone info for Renton.

Planting Calendar for Marigold

Frost tolerance for marigold:	Not tolerant of frost.
When to plant:	After the last frost.

Since marigold require warm weather you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant marigold in Renton is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant marigold and expect a good harvest is probably August. You probably don't want to wait any later than that or else your marigold may not have a chance to fully mature. If you are starting your marigold 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 March 15 in Renton. You should expect an average low temperature of 15°F in the coldest months of winter.

Keep in mind that USDA zone info for Renton is just an average and the actual date of last frost will vary from year to year. Half of the time in Renton it frosts late in the year after March 15 so make sure that you are ready to protect your marigold if you have a surprise late frost.

USDA Zone Info for Renton

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 Renton

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