When can I plant Borage in Zone 4a

One of the first steps we take when we are estimating our gardening schedule is find our USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for our area.

The earliest that you can plant borage in Zone 4a should be figured out by reviewing the USDA zone info.


Planting Calendar for Borage

Frost tolerance for borage: Tolerant of some frost.
When you should plant them: Up to 5 weeks before last frost.

Borage are one of those plants that can tolerate a little bit of cold weather which means that you can get them planted earlier than more sensitive plants.

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

The earliest that you can plant borage in Zone 4a 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 borage and expect a good harvest is probably August. If you wait any later than that and your borage may not have a chance to grow to maturity. If you are starting your borage indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Zone 4a the average date of last frost happens on May 15. We should expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Zone 4a is not always accurate our actual date of last frost is different every year. Half of the time in Zone 4a we get surprised by a frost after May 15 so always be ready to protect your borage if we have a late frost.

USDA Zone Info for Zone 4a

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 Zone 4a

You may be interested in our other planting guides for Zone 4a.