One of the first steps you take when you are figuring out 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.

One way of estimating when to plant flax is to use the USDA zone info for Harvard.

Planting Calendar for Flax

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

Since flax are one of those plants that can tolerate a little bit of cold weather you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant flax in Harvard is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant flax and expect a good harvest is probably September. If you wait any later than that and your flax may not have a chance to grow to maturity. Starting your flax indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Harvard. You can expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Harvard is not always accurate and the actual date of last frost is different every year. Half of the time in Harvard you get surprised by a frost after April 15 so always be ready to protect your flax if you have a surprise late frost.

USDA Zone Info for Harvard

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Harvard

You may be interested in your other planting guides for Harvard.