Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when to plant larkspur is to use the USDA zone info for Sterling.

Planting Calendar for Larkspur

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

Since larkspur are very cold tolerant you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant larkspur in Sterling 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. You probably don't want to wait any later than that or else your larkspur may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your larkspur indoors.

Last Frost Date

In Sterling the average date of last frost happens on April 15. It might get as low as -20°F during 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 Sterling and it changes from year to year. Since half of the time in Sterling it frosts late in the year after April 15 be ready to cover your larkspur in the event of a surprise late frost.

USDA Zone Info for Sterling

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 Sterling

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