The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Alton you will be able to estimate when to plant bougainvillea.

Planting Calendar for Bougainvillea

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

It's a bad idea to plant bougainvillea until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant bougainvillea 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 bougainvillea and expect a good harvest is probably August. You probably don't want to wait any later than that or else your bougainvillea may not have a chance to fully mature. You can get started a little bit earlier by starting your bougainvillea indoors.

Last Frost Date

The average date of last frost is April 15 in Alton. In the coldest months of winter you should expect an average low temperature of -10°F.

Keep in mind that USDA zone info for Alton may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Alton it frosts late in the year after April 15 so be sure to be ready to cover your bougainvillea 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.