One of the first steps you take when you are estimating 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.

It's possible to estimate when to plant dahlia by checking out the USDA zone info for Watertown.

Planting Calendar for Dahlia

Frost tolerance for dahlia:	Not tolerant of frost.
When to plant:	After the last frost.

You can not plant dahlia until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant dahlia in Watertown 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 dahlia and expect a good harvest is probably August. If you wait any later than that and your dahlia may not have a chance to really do well. Starting your dahlia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Watertown the average date of last frost happens on April 15. You should expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that USDA zone info for Watertown is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Watertown it frosts late in the year after April 15 so be sure to be ready to cover your dahlia if you have a surprise late frost.

USDA Zone Info for Watertown

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Watertown

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