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.

A way of estimating when it's the best time to plant polygonums is to consult the USDA zone info for Gaithersburg.

Planting Calendar for Polygonums

Frost tolerance for polygonums:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant polygonums 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 polygonums in Gaithersburg 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 polygonums and expect a good harvest is probably August. Any later than that and your polygonums may not have a chance to really do well. You can get started a couple of weeks earlier by starting your polygonums indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Gaithersburg. You should expect an average low temperature of 0°F in the coldest months of winter.

Always keep in mind that USDA zone info for Gaithersburg is just an average and the actual date of last frost is different every year. Since half of the time in Gaithersburg last frost occurs after April 15 be ready to cover your polygonums if you have a surprise late frost.

USDA Zone Info for Gaithersburg

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Gaithersburg

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