One of the best tools that you have as gardeners to help us figure out 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.

It's possible to figure out when it's possible to plant nasturtium by reviewing the USDA zone info for Zone 4b.

Planting Calendar for Nasturtium

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

It's probably a bad idea to plant nasturtium until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant nasturtium 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 nasturtium and expect a good harvest is probably August. Any later than that and your nasturtium may not have a chance to really do well. If you are starting your nasturtium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 4b. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Zone 4b may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 4b there is a last frost after May 15 so just be sure to be ready to protect your nasturtium in the event of a 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.