One of the first steps you take when you are figuring out 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.

In Olean you can determine when it's the best time to plant dahlias by referring to the USDA zone info.

Planting Calendar for Dahlias

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

Dahlias do not do well in cold weather which tells us that it's important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant dahlias in Olean 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. You probably don't want to wait any later than that or else your dahlias may not have a chance to grow to maturity. If you are starting your dahlias indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Olean. It might get as low as -20°F during the coldest months of winter.

Keep in mind that USDA zone info for Olean is just an average and the actual date of last frost will vary from year to year. Half of the time in Olean last frost occurs after April 15 so be sure to be ready to protect your dahlias if you have a late frost.

USDA Zone Info for Olean

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 Olean

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