The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when it's the best time to plant mustard greens is to look at the USDA zone info for Alton.

Planting Calendar for Mustard greens

Frost tolerance for mustard greens:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since mustard greens are moderately cold tolerant you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

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

The last month that you can plant mustard greens and expect a good harvest is probably September. Any later than that and your mustard greens may not have a chance to grow to maturity. If you are starting your mustard greens indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Alton. You should expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that USDA zone info for Alton is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Alton you get a frost after April 15 be ready to protect your mustard greens if you have 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.