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.

A common way of estimating when it's possible to plant alstromeria is to refer to the USDA zone info for Silverton.

Planting Calendar for Alstromeria

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

Alstromeria are one of those plants that can tolerate a little bit of cold weather which tells us that you can plant them a little bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant alstromeria in Silverton 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 alstromeria and expect a good harvest is probably September. You probably don't want to wait any later than that or else your alstromeria may not have a chance to really do well. Starting your alstromeria indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Silverton the average date of last frost happens on March 15. You should expect an average low temperature of 10°F in the coldest months of winter.

Keep in mind that USDA zone info for Silverton is an average and the actual date of last frost is different every year. Since half of the time in Silverton you get a frost after March 15 be ready to cover your alstromeria if you have one of those late frosts.

USDA Zone Info for Silverton

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Silverton

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