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When is the last frost date?

Posted by saly Z7, NW, USA (My Page) on
Fri, Apr 14, 06 at 3:48

I am in Seattle region.
Can anybody tell when is the last frost date here?
I am growing tomatoes from seeds.
Indoor seedlings are up and I am wondering what is the right time to transplant them outside.


Follow-Up Postings:

RE: When is the last frost date?

There is no definitive last frost date - it can vary from year to year and location to location. The average last frost date is generally considered to be around March 22-24 in this area but that only means there is a 50% chance we will not receive frost after that date.

There are other considerations for planting out tomatoes and other warm season or tender crops. These require warm soil conditions as well as rather balmy nighttime temperatures. It is typically recommended to not plant these out until soils reach 50F or more and night temperatures are consistently above 50F, typically mid to late May - Mother's Day is often used as a benchmark, but in some years, even that date is premature.

RE: When is the last frost date?

  • Posted by bboy z8 WA USA (My Page) on
    Fri, Apr 14, 06 at 22:32

WSU used to say after June 1 for planting out tomatoes and other tender plants. Seems about right to me, as it is often not consistently summerlike until June (or later, thus jokes about rain on 4th of July). Nurseries are out of full selection by then, so you have to start your own ahead of time or buy early and shelter them until it warms up enough--being sure to watch that the nursery didn't chill them before you bought (look for yellowish bleached appearance to newest part of plant, in center of top).


Every area may be slightly different. Even on our island it varys greatly from one end to the other. I have had any frost in many weeks and I doubt that will get anymore until next Fall sometime. There are so many microclimates in the PNW they could never all be listed on a zone map. Topography plays a big roll in our climate. There are many cool valleys that will most definately still see some frost. Areas nearer to the ocean are probably safe. I still wouldn't be sticking my tomatoes or peppers out in the garden anytime soon. Cheers, Joe

RE: When is the last frost date?

What about tomatoes planted in wall'o'waters? Has anyone here tired that and how much earlier were you able to plant them out? I've been thinking of trying it this year.


RE: When is the last frost date?

Don't forget to harden off those plants before you put them out :)

Typically, you don't want to put them out until nighttime temps are consistantly in the 50s. However, that being said, last year I put mine out when nightime temps were in the upper 40s, and the servied just fine. They didn't start really growing until late july though.

I just hope that it warms up sooner and more this year!

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