When can I plant Sweet Peas in Zone 4b

One of the first steps we take when we are making a decision about our gardening schedule is find our USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

You can determine when it's the best time to plant sweet peas in Zone 4b by checking out the USDA zone info.


Planting Calendar for Sweet Peas

Frost tolerance for sweet peas: Tolerant of a very small amount of frost.
When you should plant them: Up to 3 weeks before last frost.

Since sweet peas are barely cold tolerant you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant sweet peas
Possibly ok, but a risky time to plant sweet peas
Probably not a good time to plant sweet peas

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

Last Frost Date

In Zone 4b the average date of last frost happens on May 15. In the coldest months of winter we can expect an average low temperature of -25°F.

Always keep in mind that our actual date of last frost is just an average because it is based on the USDA zone info for Zone 4b and it will vary from year to year. Half of the time in Zone 4b last frost occurs after May 15 so make sure that you are prepared to protect your sweet peas 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 our other planting guides for Zone 4b.