Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Sterling it's possible to estimate when it's the best time to plant oriental poppies.

Planting Calendar for Oriental poppies

Frost tolerance for oriental poppies:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Oriental poppies do ok in some cold which means that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant oriental poppies 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 oriental poppies and expect a good harvest is probably September. Any later than that and your oriental poppies may not have a chance to fully mature. If you are starting your oriental poppies indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Sterling. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Sterling is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Sterling there is a last frost after April 15 be ready to cover your oriental poppies in the event of a 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.