One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of making a decision about when to plant dahlia is to look at the USDA zone info for Union.

Planting Calendar for Dahlia

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

Since dahlia are not cold tolerant you have to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant dahlia in Union 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 grow to maturity. If you are starting your dahlia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Union. In the coldest months of winter you can expect an average low temperature of 10°F.

Since the USDA zone info for Union is just an average the actual date of last frost is different every year. Since half of the time in Union last frost occurs after March 15 be ready to protect your dahlia in the event of a surprise late frost.

USDA Zone Info for Union

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Union

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