One of the first steps you take when you are determining your gardening schedule is find your 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.

The USDA zone info for Rio Vista should be used to estimate when it's the best time to plant monarda.

Planting Calendar for Monarda

Frost tolerance for monarda:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since monarda do ok in moderate cold you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant monarda in Rio Vista 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 monarda and expect a good harvest is probably September. Any later than that and your monarda may not have a chance to really do well. If you are starting your monarda indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Rio Vista. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Rio Vista is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Rio Vista there is a last frost after February 15 so make sure that you are prepared to protect your monarda if you have one of those late frosts.

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.