One of the best tools that you have as gardeners to help us figure out 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.

You will be able to determine when it's possible to plant marigold by checking out the USDA zone info for Rio Vista.

Planting Calendar for Marigold

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

It's a bad idea to plant marigold until after the last frost when the weather gets warmer because they are not cold tolerant.

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

The last month that you can plant marigold and expect a good harvest is probably September. If you wait any later than that and your marigold may not have a chance to really do well. If you are starting your marigold indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Rio Vista the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Rio Vista is an average the actual date of last frost will vary from year to year. Half of the time in Rio Vista last frost occurs after February 15 so make sure that you are ready to protect your marigold if you have a late frost.

USDA Zone Info for Rio Vista

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Rio Vista

You may be interested in your other planting guides for Rio Vista.