One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to figure out when it's possible to plant monarda by using the USDA zone info for Rialto.

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.

Monarda do well in very little cold which tells us that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant monarda in Rialto 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. Starting your monarda indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Rialto. In the coldest months of winter you can expect an average low temperature of 30°F.

Just be sure to remember that USDA zone info for Rialto is an average and the actual date of last frost changes from year to year. Half of the time in Rialto you get a frost after January 31 so make sure that you are prepared to cover your monarda in the event of a surprise late frost.

USDA Zone Info for Rialto

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 Rialto

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