One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. 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 a good idea to plant sanvitalia in Alton by looking at the USDA zone info.

Planting Calendar for Sanvitalia

Frost tolerance for sanvitalia:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Sanvitalia are one of those plants that can tolerate a tiny bit of cold weather which means that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant sanvitalia in Alton is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant sanvitalia and expect a good harvest is probably August. If you wait any later than that and your sanvitalia may not have a chance to fully mature. Starting your sanvitalia indoors is a great way to get them started a little bit earlier.

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.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Alton and it changes from year to year. Half of the time in Alton it frosts late in the year after April 15 so make sure that you are prepared to protect your sanvitalia 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.