Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when to plant angel's trumpets by looking at the USDA zone info for Williston.

Planting Calendar for Angel's Trumpets

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

Angel's Trumpets are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can start planting them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant angel's trumpets in Williston 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 angel's trumpets and expect a good harvest is probably August. If you wait any later than that and your angel's trumpets may not have a chance to fully mature. If you are starting your angel's trumpets indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Williston the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Williston is an average the actual date of last frost is different every year. Since half of the time in Williston you get a frost after May 15 be ready to protect your angel's trumpets if you have one of those late frosts.

USDA Zone Info for Williston

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Williston

You may be interested in your other planting guides for Williston.