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.

The USDA zone info for Roy should be looked at to determine when to plant dahlia.

Planting Calendar for Dahlia

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

It's a bad idea to plant dahlia until after the last frost because they do not do well in cold weather.

The earliest that you can plant dahlia in Roy 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. Any later than that and your dahlia may not have a chance to really do well. You can get started a few weeks earlier by starting your dahlia indoors.

Last Frost Date

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

Just be sure to remember that USDA zone info for Roy is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Roy last frost occurs after April 15 be ready to cover your dahlia in the event of a surprise late frost.

USDA Zone Info for Roy

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 Roy

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