With that grammar, you call others stupid? Wow...

If it bothers you about reading folks zones then don't read it. I personally like to know where you all come from. And I don't care about my grammar. At my age-- ain't gonna change me -- so there

It is true that USDA zone numbers relate to winter conditions but there is a co-relation between zone number and LFD. And there is a direct co-relation between LFD and plant out time. Also, generally lower zone number goes with shorter tomato growing season.

For example : you will have a much late LFD in zone 4 than zone 7 or 8.

But when you get into the middle of summer , zone number has very little or no significance when it comes to growing tomatoes. JMO

Sey

Like Lar says... don't read what you don't want to read.

I don't really have a frost date - I mean technically my area does, but it doesn't frost here as a rule and the LFD is just about useless, as we could have a freak frost at any point, but 9 times out of 10 have no frost at all. I generally plant out summer plants a month to two months before my LFD, because I can.

As lease the zones give you some idea to try to help others, versus me here in zone 9/10 telling someone in Zone 4 that it's just fine to put their transplants out in February. Or someone in Zone 5 telling me that I should never start tomatoes at Christmas.

the zones and frost are not even close to related this can be clearly seen if overlay one map over other.

In my area my last expected frost is middle of May but I've seen heavy snow in June. And if I wait till then I might as well not plant as I could have snow the first of Sept. I go by three zones - 3-4-5-6

I disagree. The correlation between last frost date and zone number can be quite poor. I used to live in the Pacific Northwest, in USDA zone 8b. My LFD was the end of April. I'm now in central Texas, in the same USDA zone, and my LFD is now late February. So that's two months different in LFD. So if someone just tells me that they're in 8b, I don't have a clue when they should set out their tomatoes. Not a clue. The USDA zone numbers are useful mainly for establishing the hardiness of perennials and although tomatoes can be gardened that way, the vast majority of people don't. In fact, if you're not in USDA zone 10, don't even bother.

That being said, there are lots more informative zone descriptors for vegetable gardeners. In fact the best thing to do is just tell people where you are! That would be more interesting to me than any zone number

If you would have posted the above post as your first post, your argument would have been much more powerful...

When we say there is a direct co-relation, that does not mean a 100% co-relation.

Speaking of my own experience, I used to live and garden in Atlanta Georgia , zone 7b. I remember well that our LFD was around April 7. Now I am in north of Seattle, WA. My zone number is 7b and our LFD is the same April 7-10. Almost 95% co-relation.But the summer condition are very different.

Another thong is that we are talking about a ball park number not for an exact date.

Sey

If it correlates in one place, that's nice for you, but in general, I don't think you can count on it, and with no other information about location, a correlation you can't count on isn't worth that much. In my case, two months isn't ball park. It's more like national park. Seriously, if I told you you on the basis of your USDA zone to plant out two months earlier than you should, that would be a total disaster. I'll add that USDA zones don't come close to providing fair warning about summer heat. In the two locations I mentioned, both at USDA 8b, the summertime temperatures are wildly different. I used to garden in heat zone 1, and now I find myself in heat zone 10 which are at opposite ends of the heat zone range in the continental US.

daninthedirt(Cent TX; HZ10, Sunset z30, USDA z8a) I
disagree. The correlation between last frost date and zone number can
be quite poor. I used to live in the Pacific Northwest, in USDA zone 8b.
My LFD was the end of April. I'm now in central Texas, in the same USDA
zone, and my LFD is now late February. So that's two months different
in LFD. So if someone just tells me that they're in 8b

++++++++++++++++++++++++++

Just a curiosity : Wher in PNW you were in zone 8b tha LFD was end of April (name of town) ?

And where in TX you are in zone 8b with LFD is late February (name of town) ?

Thank you

Sey

I think, in general, that if you fuss at people, certainly if you tell them they 'look stupid' they may not post or ask questions.

Whether you think the info is relevant or not, (you certainly don't have to reply if some asks you) trying to mandate what people ask or don't isn't helpful.

I thought zone and location is the typical info requested. Zone location and frost dates becomes a little cumbersome and I doubt would be followed. Zone is the only government, well documented system and while is it fairly limited for vegetable gardening it does tend to have several correlations, though they don't always hold true, which is why it is good to ask for location.

In reality, summing down gardening conditions to any single number is pretty "stupid", but that's what people want to do.

I was in - Tigard OR (near Portland) ; zone 8b, LFD April 20

I am now in - Dripping Springs TX (near Austin) ; zone 8b, LFD February 26

My tomatoes have been outside for three weeks and are doing great, BTW. Of course, in August, my tomatoes will have totally shut down, while those in Tigard will be producing profusely.

I should say that we definitely shouldn't stop asking people for their zone, but the USDA zone numbers just aren't very informative. The Sunset zones make a lot more sense, though there are a lot more of them which tends to confuse the issue. The higher the number, the colder it is. The Sunset folks say exactly what we're saying here -

"A plant's performance is governed by the total climate: length of
growing season, timing and amount of rainfall, winter lows, summer
highs, wind, and humidity. Sunset's climate zone maps take all these factors into account,
unlike the familiar hardiness zone maps devised by the U.S. Department
of Agriculture, which divides most of North America into zones based
strictly on winter lows. The U.S.D.A. maps tell you only where a plant may survive the winter;
our climate zone maps let you see where that plant will thrive
year-round."

http://www.sunset.com/garden/climate-zones/climate-zones-intro-us-map

The sunset zones put nyc in the same zone as Albany... Albany is a good 10F cooler on average. So here again is a nice idea, but trying to break down so many different factors into a single number is going to wind up with serious oversimplification, and require significant resources ($$) to invest in accuracy and constant review which I don't imagine is available.

Yes, that's very true. I certainly wouldn't use ANY popular zone number to be indicative of LFD, but the Sunset zones at least try to give a rough idea of growing climate. The USDA zones don't.

With the hills and valleys mountains and deserts its impossible to have an accurate temp estimate. I live on a mountain and down the road aways the temp could be 15degs different and in the same zone and mother nature plays a big part of when you can plant out. Like I said my last freeze date is May. But even then I have to protect the plants. The wind is a big factor it will ruin the plants. So where does that come into play using zones? I use zones as an estimate and I do use zones.

FWIW, LFD is the average last date that the air temperature gets below freezing. Because low humidity and high winds can lead to frost, even when the temperature is somewhat above freezing, LFD really can't quite be considered the average date of last frost! So although zones aren't a good indicator of LFD, the LFD may not even be a dependable average date for last frost. Howzzat for you? These zones and average dates are loaded with caveats, and gardening experience is what lets you use them successfully. So conversations like this are of some value, I think.

OK---FWIW

Let me add that, for lack of telling me anything more specific about where you are, you can tell me your USDA zone, but that info isn't very useful in giving cogent advice about vegetable gardening. I'm not sure how USDA zones became sort of traditional for sharing advice about vegetable gardening, but I suspect it was long before any other climate metrics had been developed, and long before there were any useful online tools for getting local weather statistics. Those zones were first laid out by the USDA in the 1920s, when folks in Minnesota didn't have a clue about gardening in Tennessee, and what perennials would survive there. I think Henry Skinner, then director of the National Arboretum, did these maps, and they certainly weren't made for vegetable gardening. Perhaps we should just be sharing zip codes?

People may not like how nondescript USDA Hardiness Zones are, but along with a general location, they are extremely helpful for a quick, easy to understand overview of a particular area's climate expectations.

Give me your Sunset Zone, and I'm sorry, I don't have time to look that up and translate. That is for you to do the research and understand your own zone. I'll even consider you lazy for having the internet to post on a site like this, and yet you would rather impose on others rather than do the research work yourself.

Give me your general location, and your Hardiness Zone, and If I can, I'll be glad to help. The Hardiness Zone tells me how cold it can get, and the location gives me enough insight (barring micro-climates that fall under the same subset of individual climates as Sunset Zones) to offer an overview.

As for USDA Hardiness Zones and LFD... before you could look up your own zip code and get detailed information of your local climate and weather, USDA Hardiness Zones were extremely helpful (and thus, to us who do not live your life - insight into your general conditions,) and still are...

So, if I ask for USDA Hardiness Zone, and your location, I will have enough information to point a person in the right direction. If that person needs more details, it's up to them to some work for themselves. I'll be glad to help you learn how to fish, let you know what fish live in the types of water near you, but sorry, unless you are somehow debilitated, I'm not going to do your fishing.

And gridgardener, it's a good thing you know it all, otherwise finding help from the people here would be a challenge.

Just give me your location. I don't need a hardiness zone number.

Please understand. I'm not saying zip codes and or Sunset numbers are easier to use than USDA hardiness zone numbers. I'm just saying they provide vastly more information.

This is an old, old debate and utterly pointless for several reasons. Garden zones have been with us for decades and commonly used throughout the gardening landscaping industry. They are as pointless as one wants to make them or as useful as one wants to make them. But they are not going away as they are too ingrained in the industry.

Some people don't like to indicate where they are located. Don't know why, they just don't. And we can't even get most posters to be aware that their country much less their part of the country is relevant to their question. So if we can get them to at least indicate a zone it gives us a better starting point than just their user name ever will.

So if you don't like them that's your choice. Fine, ignore them. But that in no way makes the rest of us who do find them useful for several reasons stupid, dumb, ignorant, uninformed, etc.

Dave

I'm certainly not calling anyone stupid, dumb, or ignorant, and the OP was hardly being civil by doing so. When someone asks a question, and doesn't want to give their location (state, county, city, zip code, whatever), but just wants to give ONE NUMBER, I guess that at least puts us in the right frame of mind. That is, maybe we're not talkin' snow shovels here. But there are many people who simply don't understand that those numbers are just winter hardiness zones and don't really pertain to most summer gardening. So the discussion isn't pointless. This is just a plea to people who want cogent advice about gardening, or have something to offer about what works for them, to PLEASE provide more than your hardiness zone number. That number will mainly tell me what will survive your winter.

I've never seen frost form on a very windy night. In fact, I have seen orchardists create wind with large fans to deter frost from settling in.

Sorry Dan, I wasn't referring to you.

Dave

No problem, Dave. The proposition I was responding to was that hardiness zones are instructive about LFD, and I was just saying that there is good reason to believe that they are not. If people really want to be super coy about where they are, I have no big problem with USDA zones, but the quality of the information transferred will suffer. Again, I've gardened in two locations that have the same USDA zone designation but are awesomely different in how one actually approaches gardening. Took me a while to relearn everything.

As to frost on a windy night, it can only happen if the humidity is low, such that the dew point is well below freezing. If you're in a humid environment, that won't happen readily.

While in Germany, I saw the most remarkable Hoar frost that had crystals up to three inches long, and while the wind was calm, the humidity was fairly low.

Getting back to the topic at hand, both parties bring up a fair point... the USDA maps are not really a good indicator of when one's particular LFD will be, but it is worthy to know a person's zone # when they come here to post, asking questions.

Wow! We certainly have moved on from heirloom vs hybrid!

I hang out on a bunch of forums, and am pretty judicious about when I choose to post "original content" (and never just to tell folks they are stupid!), but I wanted to take a moment to to say that Sunset zones work well for me.

I am reading threads about plant out dates weeks before mine, even though it rarely gets below 32 for more than a few hours around here.

Around here, for tomatoes, soil temp rules, and seems to be a function of the lack of humidity, and the huge swings between nighttime and daytime temps we get out west.

Added to that, my "heat zone" is the second "rule", because there is surprisingly little time to get them going before it is too hot for some tomatoes to set fruit.

Great for peppers, though!

Folks not far from me may have a completely different set of issues, but we have SOME issues in common for growing many things.

So I won't usually ask, but will always read posts about my Sunset zone.

I just looked up my frost date; it was March 2nd, almost a MONTH later than the next city! They get about 30 percent to more ocean influence there! We say that the summer highs drop about 10 degrees every time you pass a "mountain" (really a "hill"), so it can be 100 degrees in the Sacramento Valley, and 65 in San Francisco, maybe 65 miles away.

nanelle_gw,

I was thinking exactly the same thing reading this thread. Where I am, if you go 10 miles east as the crow flies, daytime temperatures can be 10-15 degrees warmer during the day, and 10-15 degrees colder at night. Go 10 miles to the west, and it can be 10 degrees cooler during the day and 10 degrees warmer at night. I have no problem growing tomatoes and having them set fruit year round, but the people to the east of me have to worry about night temperatures (and frost) and the hot part of the summer, the people to the west have to worry about temperatures being too cool, humidity related diseases from the fog they tend to get in early summer, and not getting warm enough early enough to get things going, or grow things like peppers successfully.

I really appreciate people using all the guides - USDA, Sunset (if applicable) and location, helps a ton when trying to figure out people's issues, especially here out west. Otherwise, if I haven't actually gardened where you are, I really wouldn't have a clue.

"I really appreciate people using all the guides - USDA, Sunset (if applicable) and location, helps a ton when trying to figure out people's issues, especially here out west."

Sooooo......now I MUST know! what's yours?

Oh snap! Now I see it! NVM.

Anybody else notice zones may not show up with the post right away? That is why my screen name has it twice....sometimes. I think it has to do with gardenweb vs Houzz regstration.

This site still takes some getting used to

I will underscore the rule about Heat Zones. In the southern U.S. those are profoundly important in planning summer garden strategy. Here in 8b central Texas, my heat zone is 10="Oh, gawd, it gets hot!" In my old 8b garden, in the Pacific Northwest, the heat zone was 1="Duh, what? It gets hot here?" But you know, even on the SW Oregon coast, where the hardiness zone is 9b (!) the heat zone is still 1.

Lol... GASP!!!!! Asking for zones nanelle, especially those pesky hardiness ones, is verboten!

But this is my point. If I am to help someone, all that is required is basic info about general climate and location. Any specifics about Sunset Zones, Zip Codes, even LFD... etc... are too detailed to do any good for basic advice. Sure, each of those are important for the individual to understand how to apply them in their own efforts, but unless you are going to hold someone's hand, or are just curious, it's rare that the person offering advice need such details.

Just as examples...

Sunset Zones... there are 45 of those things! Is anyone without perfect memory recall going to claim they know them all by rote, and can give advice without looking them up? They are for the individual gardener to learn about and understand (if they so desire.) I've looked mine up once, saw the number, and immediately ignored it! It's fine to learn about, but all I have to say when giving advice about LFD (or anything else regarding details beyond basic location and Hardiness Zone) is something like... "Plant out after, or around your LFD." Depending on the experience of the gardener to whom I am speaking, I may let them know they can do a web search for their zip code to find their LFD...etc...

And... even if I know their Sunset Zone, or their LFD, or any such details, I still don't know (and they may not either) any considerations about micro climates. "Hey Thomas Jefferson, how did you plant all those Southern-thriving plants in your garden, when your neighbors could not?" Micro Climates!

Sorry, but this "Stop asking" nonsense, is just that... nonsense! And an attempt by someone to sound knowledgeable. I'm sorry to be so blunt, and maybe I should follow Grandma's advice to 'don't say anything at all...', but it's also wrong to allow a bully to post publicly about how others discuss these matters.

Someone correct me if I'm wrong because I'm not 100 percent certain but I don't think there is really such a thing as LFD. There is an average LFD that is based on average temperatures. You can get frosts after that date if the temperature is below average. I know here May 10th was always considered the safe date but the last two years we have had frosts after that date and one of them was on the 18th. On the website where you put in your zip it gives the average LFD as April 30th with two weeks blocked out on either side. So that is fairly close but still keep an eye out for another week or so. :)

rgreen, you make a good argument that zone numbers of any kind don't do a lot of good. So just dispense with any zone numbers (USDA Hardiness, Sunset, whatever), and just tell me where you are! Like, your state - two letters instead of one number. I actually have a good picture in my mind how gardening in ND differs from that in LA irrespective of hardiness numbers. Actually, if you give me your ZIP code too, I can look up all the detailed zone numbers I might want, depending on how much handholding you need. The OP was a bit undiplomatic, but provoked some good discussion here.

I'll say it again, and I think this was the point the OP was undiplomatically trying to argue, that USDA hardiness zones don't really tell you a lot about summer gardening.

Yes, the average LFD is well defined. You go through the weather records and determine the average date of the last time the temperature got below 32F It's a lot of numbers to sift through, but arithmetically it's a well defined problem. BUT, as well all know that's not necessarily the average last frost date. Huh? The LFD doesn't mean last frost? Nope. It means that average date of the last time it was 32F. If the humidity is low, and the dew point is well below 32F, strong winds can cause frosting even if the air temperature is above 32F. That's part of the reason you feel colder outside when the wind is blowing. So in principle the last frost date is going to be AFTER the LFD. Maybe by days, maybe by a week, depending on whether you're in an area with low dew points, and I guess whether you're in an area that is prone to strong winds.

"just tell me where you are! Like, your state - two letters instead of one number. "

daninthedirt, I live in CA.

I get what you are saying, I used to live elsewhere, and know "where California goes" may not mean much, but for me, two letters just doesn't work. But then I don't give much advice, mostly looking for it, so there's that.

So....anybody got advice for growing "dwarf project" tomatoes in Earthboxes in Sunset zones sometimes 9, usually 14?

Dan,

Are you saying plants are affected by the wind chill factor? The only reasons we feel "wind chill" is because we produce a "large" layer of heat that can be blown away by the wind. Plants don't have this blanket of warmth.

Nope. Wind chill is different. Exactly as you say, wind chill is where the layer of warm air that surrounds you is blown away by the wind. What I'm talking about is evaporation of water. In fact, if something is completely dry, it won't ever freeze above 32F, even with lots of wind. But plants are moist inside, and some of that moisture can appear on the leaves. That's why plants dry out, because the leaves don't seal in moisture. If you take a container of water and blow air across it, the temperature of that water will end up being less than the air temperature that blew across it. Unless the humidity is 100%.

In fact, that's exactly how the "wet bulb" humidity measurement works. You take a thermometer and surround it with a moist sheath. Then you swing it around your head. That thermometer will read lower than the air temperature - a temperature called the dew point, by an amount lower that depends on the humidity.

In terms of human warmth, what this is more about is when you come out of the swimming pool, you're all wet, and the wind makes you feel LOTS COLDER than if you were dry.

http://www.landscapingnetwork.com/planting-zones.html If you will look at this, you will find the the zones work well in the south. The sunset work better out west. However, I take exception to anyone calling me stupid and it is even worse if they can't spell. You will see that mine says 7b AL for reference only. This is so anyone will know that I am not way up north, overseas, or out west. I do like to get feedback from anyone no matter where in the world they are located. Their plants are located over there and they're very pretty!

As I have said before, I think, USDA zone numbers indicate winter conditions, eg, which shrubs, trees, perennials can survive and over winter. So the lower the number the harsher, longer and colder the winters.

When does the winter ends:

LFD is a good point to consider the end of winter. It is a statistical number based on historical weather data collected for a given location. It is generally based on 90/10 probability which means there is a 90% probability that no frost will happen after that date . You can also find 95/5 LFD.

So that is where USDA zone numbers and LFD meat. Both are related to winter. Otherwise, passed that date there is no or very little significance of zone numbers to summer gardening. JMO

Sey

Other uses for USDA zone Number:

On almost all seed packets there is USA map , showing the zone numbers on it. It is related to sowing seeds of certian vegetables. Again, it is related to LFD. For example you can plant potatoes, onions, cabbage, ... few weeks before LFD

I'm sure you're right Seysonn. For me the USDA number was the first planting number info I became aware of which lead me to find out about the LFD date and so on. When I first started with tomatoes I guess I thought everyone in the country planted at the same time! I'm in zone 9b-10 which indicates to me I'm in an area with a long growing season, same as 9b-10 in Texas or Florida, etc. so it does have significance. We don't need to rush our tomatoes into the garden and the LFD date is not as important. I know, not very scientific....

Probably time to drop this, but no, that isn't where USDA zone numbers and LFD meet. My point is that they don't meet. USDA zone numbers tell me how cold your winter gets which only very very broadly tells me when your spring starts. Maybe within a few months. One is measured in temperature, and the other in time. So although ice skating and LFD are both are related to winter, they don't really meet.

Actually, you make a good point that if people told me their LFD, that would tell me a lot more about their vegetable gardening conditions than their USDA zone would!

But I did not realize that LFDs were usually 90/10. I always assumed they were just 50/50, which leads me to plant out a week or two after LFD as insurance. Thanks for the info.

Rhoder,

The LFD is important to me. Texas has a long growing season, but that is deceptive as tomatoes will shut down production in the height of summer heat, so I try to plant as soon after the LFD as I can in order to get tomatoes before the plants shut down.

That's a good point. We in Texas have a long growing season but we don't have a particularly long fruiting season for tomatoes and peppers.

Likewise, the SF Bay area technically has no LFD and many Bay Area cities are listed as USDA 9 or 10. We can garden year round! Or can we?

Both the zone and LFD facts are still misleading for us, as neither reflects the lack of heat for most of the year here, or that our "summer" heat typically comes between August-October.

The better point of reference is conditions in our area. When are night temps consistently in the 50s? Daytime temps consistently in the 70s? Soil temps, etc. USDA and LFD don't cover any of those things for us.

That's true even here to. For instance, last frost is October 30th, but by that point there is so little sun, it isn't really possible to grow anything. There are too many factors to sum it down to a single number.

It does make a great pickup line though. Hey baby, what's your USDA hardiness zone.... I am not sure what else would roll off the tongue so well.

Peter if you ever actually got a woman that way, I don't think it had anything to do with tomatoes.

Of course I was just kidding... :)