One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

You can determine when you can plant alstromeria in Douglas by using the USDA zone info.

Planting Calendar for Alstromeria

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

Since alstromeria are moderately cold tolerant you can plant them just a bit earlier in the year than other frost tender plants.

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

The last month that you can plant alstromeria and expect a good harvest is probably August. You probably don't want to wait any later than that or else your alstromeria may not have a chance to fully mature. Starting your alstromeria indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Douglas. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Douglas is not always accurate the actual date of last frost will vary from year to year. Half of the time in Douglas you get a frost after May 15 so be sure to be ready to protect your alstromeria in the event of a surprise late frost.

USDA Zone Info for Douglas

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Douglas

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