The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Watertown you should be able to determine when you can plant flax.

Planting Calendar for Flax

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

Flax do well in moderate cold which tells us that you can start planting them earlier than other frost tender plants.

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

Last Frost Date

In Watertown the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Watertown may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Watertown it frosts late in the year after May 15 so make sure that you are prepared to protect your flax in the event of a surprise late frost.

USDA Zone Info for Watertown

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 Watertown

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