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 way of getting a good idea when it's possible to plant alstromeria is to look at the USDA zone info for Zone 5b.

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 one of those plants that can tolerate a little bit of cold weather you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant alstromeria in Zone 5b 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 grow to maturity. 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 April 15 in Zone 5b. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Zone 5b is just an average the actual date of last frost is different every year. Half of the time in Zone 5b there is a last frost after April 15 so just be sure to be ready to protect your alstromeria in the event of one of those late frosts.

USDA Zone Info for Zone 5b

Here is the info for USDA Zone 5b.

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

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

Plants to Grow in Zone 5b

You may be interested in your other planting guides for Zone 5b.