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.

You can estimate when it's a good idea to plant oleander in Alton by looking at the USDA zone info.

Planting Calendar for Oleander

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

You can not plant oleander until after the last frost because they do not do well in cold weather.

The earliest that you can plant oleander 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 oleander and expect a good harvest is probably August. Any later than that and your oleander may not have a chance to fully mature. If you are starting your oleander indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Alton. It might get as low as -10°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Alton and it changes from year to year. Since half of the time in Alton you get a frost after April 15 be ready to protect your oleander 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.