The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Janesville you will be able to determine when it's a good idea 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.

Alstromeria tend to make it in mild cold which tells us that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant alstromeria in Janesville 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 grow to maturity. Starting your alstromeria indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Janesville the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Janesville and it changes from year to year. Half of the time in Janesville last frost occurs after April 15 so make sure that you are prepared to protect your alstromeria in the event of a late frost.

USDA Zone Info for Janesville

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Janesville

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