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.

By reviewing the USDA zone info for Oswego you will be able to figure out when it's a good idea to plant larkspur.

Planting Calendar for Larkspur

Frost tolerance for larkspur:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since larkspur do well in cold you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant larkspur in Oswego is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant larkspur and expect a good harvest is probably September. Any later than that and your larkspur may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your larkspur indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Oswego. In the coldest months of winter you can expect an average low temperature of -10°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Oswego and it can change quite a bit from year to year. Since half of the time in Oswego you get surprised by a frost after April 15 be ready to protect your larkspur if you have one of those late frosts.

USDA Zone Info for Oswego

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Oswego

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