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.

The USDA zone info for Stillwater can be read to figure out when it's the best time to plant alstromeria.

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 a bit earlier in the year than more sensitive plants.

The earliest that you can plant alstromeria in Stillwater 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. Any later than that and your alstromeria may not have a chance to really do well. If you are starting your alstromeria indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Stillwater the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Stillwater is just an average the actual date of last frost is different every year. Since half of the time in Stillwater there is a last frost after May 15 be ready to cover your alstromeria if you have a late frost.

USDA Zone Info for Stillwater

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 Stillwater

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