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

It's possible to determine when you can plant marigold by using the USDA zone info for Imperial.

Planting Calendar for Marigold

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

Since marigold are not cold tolerant you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant marigold in Imperial 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 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 grow to maturity. You can get started a couple of weeks earlier by starting your marigold indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Imperial. It might get as low as 30°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Imperial and it changes from year to year. Half of the time in Imperial last frost occurs after January 31 so make sure that you are prepared to cover your marigold if you have one of those late frosts.

USDA Zone Info for Imperial

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Imperial

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