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.

The USDA zone info for Grass Valley can be looked at to estimate when 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 do well in moderate cold which tells us that you can start planting them earlier than plants that are more sensitive to the cold.

The earliest that you can plant alstromeria in Grass Valley is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant alstromeria and expect a good harvest is probably October. You probably don't want to wait any later than that or else your alstromeria may not have a chance to really do well. If you are starting your alstromeria indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Grass Valley the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Grass Valley is just an average and the actual date of last frost will vary from year to year. Since half of the time in Grass Valley you get a frost after February 15 be ready to cover your alstromeria in the event of a surprise late frost.

USDA Zone Info for Grass Valley

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°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 25°F.

Plants to Grow in Grass Valley

You may be interested in your other planting guides for Grass Valley.