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.

A common way of determining when it's a good idea to plant alstromeria is to check out the USDA zone info for Riverside.

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 start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant alstromeria in Riverside 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. Any later than that and your alstromeria may not have a chance to fully mature. 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

On average all chance of frost has passed is on April 15 in Riverside. It might get as low as -10°F during the coldest months of winter.

It's important to remember that USDA zone info for Riverside may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Riverside there is a last frost after April 15 so be sure to be ready to cover your alstromeria if you have one of those late frosts.

USDA Zone Info for Riverside

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Riverside

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