Do I have any frost date in zone 10?

I was thinking I have no frost date in zone 10. It does not get to 32 degrees in winter, last winter got to 37 as the low. Someone told me this is wrong, I do have a frost date.

I am confused since I bought a package of seeds from Botanical Interests and inside the package it says, "Frost date your first and last day is defined as the first day in spring which there is less than a 50% chance a frost will occur." Then it says to find your frost date call your garden center. This makes no sense to me.

If we never do reach 32 then we will never have a frost date. Most people who work at nurseries appear to know much less then I do, so I never bother to ask there anymore.

If a frost date is not defined as a 32 degree date, but instead the date in which I see what looks like ice on a lawn, but is white and needs to be watered before you walk on the lawn or the lawn will die every where I step, then we do have date and I can figure it out, as soon as that happens and call it a frost date. Since the lawn collects dew, then if it turns white, I could call this a frost? Then I can keep track of this and average it out, to get a frost date for reference sake.

I think I remember something about 38 degrees as a frost temp. with other conditions being right.

I don't know how accurate this is, but it might help (if it's right, it looks like you have the possibility of three days of frost on average - you lucky thing :)

http://www.floridata.com/tracks/misc/frostdates.htm

Thank you for the link and chart, that will be very useful, and I am also going to keep tract of any temps lower then 38 this winter, some winters do get down to below 32, but not every year.

Bug_Girl, you should have a County Extension office available; ours is run by Ohio State University but is actually run by the county government. Every state provides for these, and they are the best source of information for any questions you may have. Master Gardener programs are generally handled by the County Extension, and they also have access to all the references that lay-people generally don't. So even if they don't have the information in their head, they can find out for you and give you everything you need to know.

san diego is the place to live....

Yes, San Diego has no frost dates at all. I wonder what the gardening is like there?

I lived in San Diego several years ago, all tropical plants. The coldest I can remember was somewhere around mid 40's.

Boy, San Frascisco has a 3 day frost period per year. Plus if your yard is protected, maybe no frost. I will trade right now. We are, last frost, April 16th, and first frost, November 3rd.

Wow, Golddog, our last frost date is May 30, and our first frost date is Oct 15. Officially. And it does change every year. There is a very old saying here, if you don't like the weather, wait a minute.

I did not know they changed every year, I thought it was a set date. Often if a plant is well established it can survive, but a newly planted one dies.

Bug_girl, there are a few dates that don't change:

1) The average first and last frost dates do not usually change from year to year (occasionally they get revised, but not often);

2) The absolute first and last frost dates don't change unless you get a later-than-ever spring freeze, or earlier-than-ever fall freeze. For those of us who experience (suffer?) through a fairly long winter, the weather services have put together statistical charts that show the probability of a frost occurring before or after the average. At some point you get to a zero probability, which is your absolute first or last frost date.

Of course, in any given year, you could have an earlier or later freeze than the average (somewhat likely) or the absolute first or last one on record (much less likely). But having a record-setting early or late frost isn't a normal occurrence - the data have been gathered over decades, and aren't likely to be wrong :)

Does that help?

My above frost dates can't be right. The web site is really off for Pittsburgh. We are more like May 15th and October 15th.

That must mean you have such a limited growing season, if you can't put out the seedlings until May 15 and then it all over by Oct. 15? How do people in Canada deal with this, they must have it worse then any of us in the states.

People with short growing seasons have spent many years developing techniques to keep plants from freezing. They are called "season extenders" and involve things like covering tender plants with some type of fabric or glass; placing plastic on the soil in beds to help warm it up early; mulching heavily to keep the soil warmer in the fall; lots of things. I typically plant my earliest tomato crop in mid-March; I still have plants growing outside until early to mid-November. We just stand ready to protect things if necessary.