One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Richmond Hill can be read to estimate when to plant dahlias.

Planting Calendar for Dahlias

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

Since dahlias require warm weather you need to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant dahlias in Richmond Hill 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 dahlias and expect a good harvest is probably August. Any later than that and your dahlias may not have a chance to fully mature. Starting your dahlias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Richmond Hill the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Richmond Hill and it will vary from year to year. Half of the time in Richmond Hill you get a frost after March 15 so make sure that you are prepared to cover your dahlias in the event of one of those late frosts.

USDA Zone Info for Richmond Hill

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Richmond Hill

You may be interested in your other planting guides for Richmond Hill.