One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant trifolium in Alton can be estimated by looking at the USDA zone info.

Planting Calendar for Trifolium

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

Trifolium are barely cold tolerant which means that you can get them planted just a bit earlier than more sensitive plants.

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

Last Frost Date

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

Since the USDA zone info for Alton is just an average the actual date of last frost will vary from year to year. Half of the time in Alton there is a last frost after April 15 so make sure that you are prepared to cover your trifolium in the event of a late frost.

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.