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.

You should be able to estimate when to plant roses by looking at the USDA zone info for Zone 4b.

Planting Calendar for Roses

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

Roses do well in moderate cold which means that you can plant them just a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant roses in Zone 4b 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 roses and expect a good harvest is probably August. You probably don't want to wait any later than that or else your roses may not have a chance to fully mature. If you are starting your roses indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Zone 4b is just an average and the actual date of last frost will vary from year to year. Half of the time in Zone 4b last frost occurs after May 15 so be sure to be ready to protect your roses in the event of 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.