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 estimate when it's possible to plant calliopsis by using the USDA zone info for Royal Oak.

Planting Calendar for Calliopsis

Frost tolerance for calliopsis:	Not tolerant of frost.
When to plant:	After the last frost.

Calliopsis are not cold tolerant which means that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant calliopsis in Royal Oak 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 calliopsis and expect a good harvest is probably August. Any later than that and your calliopsis may not have a chance to grow to maturity. If you are starting your calliopsis indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Royal Oak the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Royal Oak and it can change quite a bit from year to year. Half of the time in Royal Oak it frosts late in the year after April 15 so be sure to be ready to protect your calliopsis if you have one of those late frosts.

USDA Zone Info for Royal Oak

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Royal Oak

You may be interested in your other planting guides for Royal Oak.