Before planting it is a good idea to find your USDA Zone info to estimate 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.

By referring to the USDA zone info for Renton 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.

Since alstromeria are moderately cold tolerant you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant alstromeria in Renton 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. You can get started a little bit earlier by starting your alstromeria indoors.

Last Frost Date

The average date of last frost is March 15 in Renton. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Renton is an average the actual date of last frost will vary from year to year. Half of the time in Renton there is a last frost after March 15 so always be ready to protect your alstromeria in the event of a surprise late frost.

USDA Zone Info for Renton

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Renton

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