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

By using the USDA zone info for Zone 4b you will be able to figure out when to plant morning glory.

Planting Calendar for Morning Glory

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

Morning Glory do not do well in cold weather which tells us that it's necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant morning glory in Zone 4b is May. However, you really should wait until June if you don't want to take any chances.

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

Last Frost Date

On average the last frost has passed is on May 15 in Zone 4b. In the coldest months of winter you should expect an average low temperature of -25°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Zone 4b and it changes from year to year. Since half of the time in Zone 4b you get surprised by a frost after May 15 be ready to cover your morning glory if you have a surprise late frost.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.