The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant marigold in Riverside should be estimated by reviewing the USDA zone info.

Planting Calendar for Marigold

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

It's probably a bad idea to plant marigold until after the last frost has passed because they require warm weather.

The earliest that you can plant marigold in Riverside 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 really do well. You can get started a couple of weeks earlier by starting your marigold indoors.

Last Frost Date

On average the last frost is on April 15 in Riverside. It might get as low as -10°F during the coldest months of winter.

It's important to remember that USDA zone info for Riverside may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Riverside you get a frost after April 15 be ready to protect your marigold if you have a surprise late frost.

USDA Zone Info for Riverside

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Riverside

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