Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's the best time to plant hibiscus in Alton by referring to the USDA zone info.

Planting Calendar for Hibiscus

Frost tolerance for hibiscus:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since hibiscus do not do well in cold weather it's necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant hibiscus in Alton 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 hibiscus and expect a good harvest is probably August. If you wait any later than that and your hibiscus may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your hibiscus indoors.

Last Frost Date

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

Remember that USDA zone info for Alton is not always accurate and the actual date of last frost is different every year. Half of the time in Alton it frosts late in the year after April 15 so always be ready to cover your hibiscus in the event of one of those late frosts.

USDA Zone Info for Alton

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 Alton

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