One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of making a decision about when to plant alstromeria is to look at the USDA zone info for Coralville.

Planting Calendar for Alstromeria

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

Alstromeria do well in moderate cold 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 Coralville 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. If you wait any later than that and 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

The average date of last frost is April 15 in Coralville. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Coralville is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Coralville you get surprised by a frost after April 15 be ready to cover your alstromeria in the event of a surprise late frost.

USDA Zone Info for Coralville

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 Coralville

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