One of the best tools that you have as gardeners to help us determine 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.

By referring to the USDA zone info for Umatilla it's a good idea to estimate 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 more sensitive plants.

The earliest that you can plant larkspur in Umatilla 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 grow to maturity. If you are starting your larkspur indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Umatilla the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Since the USDA zone info for Umatilla is just an average the actual date of last frost will vary from year to year. Half of the time in Umatilla there is a last frost after April 15 so always be ready to cover your larkspur if you have a surprise late frost.

USDA Zone Info for Umatilla

Here is the info for USDA Zone 7b.

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

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Umatilla

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