One of the first steps you take when you are figuring out 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.

You should be able to estimate when it's a good idea to plant mimulus by reviewing the USDA zone info for Riverdale.

Planting Calendar for Mimulus

Frost tolerance for mimulus:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since mimulus require warm weather it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant mimulus in Riverdale 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 mimulus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your mimulus may not have a chance to really do well. If you are starting your mimulus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Riverdale the average date of last frost happens on March 15. You should expect an average low temperature of 10°F in the coldest months of winter.

Remember that USDA zone info for Riverdale 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 Riverdale there is a last frost after March 15 be ready to cover your mimulus if you have a surprise late frost.

USDA Zone Info for Riverdale

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Riverdale

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