The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant tropical hibiscus in Billings should be figured out by looking at the USDA zone info.

Planting Calendar for Tropical Hibiscus

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

Tropical Hibiscus are not cold tolerant which means that you must wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant tropical hibiscus in Billings is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant tropical hibiscus and expect a good harvest is probably August. Any later than that and your tropical hibiscus may not have a chance to fully mature. If you are starting your tropical hibiscus indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Billings. In the coldest months of winter you can expect an average low temperature of -25°F.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Billings and it will vary from year to year. Since half of the time in Billings there is a last frost after May 15 be ready to protect your tropical hibiscus in the event of a surprise late frost.

USDA Zone Info for Billings

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Billings

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