how do seeds know they have been planted in the ground

[where_with_all]

Another burning question:

It seams to me that the best way to measure maturity is from when you first plant the seeds. Apparently though this is not how it is done. According to several books and people, maturity is measured from the time of transplant. Why?

How do the plants know if they have been transplanted?
Does that mean I will never get fruit if I don't put my seeds in the ground? Do the plants get totally confused if they are kept in containers?

Or is the maturity date some artificial guideline that is derived from the start of seeds (i.e. add six weeks to maturity date on packet to get the real date)?

Can anyone enlighten me on this?

[nctomatoman]

Actually, many old seed catalogs used to report days from seeding for maturity dates. But, overall, when you think of it, days to maturity in general are pretty meaningless, because there are just so many variables. Plants respond to favorable environment. As seeds, of course, there is no moisture, so germination is not triggered. Once a plant is growing, it will do what it can do with whatever its environment allows (I've kept hot pepper plants in 4 inch pots well past when they should have been transplanted. They actually end up fruiting, but are stunted - much shorter and lower yielding than if they were in an environment where those roots could really stretch).

Back to variables - you plant that seed, but say your soil is heavy potting soil, mine is fluffy soilless mix. Your environment is cool, mine is warm. These all significantly impact how long it takes for the seed to germinate - so for any one variety, you could have huge variables for the maturity date. Same as date from transplant - if it is a cool season vs warm season, sufficient vs insufficient moisture, full sun vs partial shade.

So I take maturity dates with a grain of salt.

[where_with_all]

NCtomatoman,

Thanks for the reply-- but if there are so many variables, how do they arrive at a maturity date at all? Do they have a controlled enviornment for measuring maturity date?

If it really is that imprecise why bother? If there are that many variables is there a way to controll the enviornment to get tomatoes faster? I.e could i get my brandywines in 60 days instead of 90??

[nctomatoman]

Good question - I think it because, relatively speaking - and in terms of generalities - varieties tend to be early, mid or late season. it is within those groupings that there is much imprecision. And they can also be inaccurate as well (I've had very late tomatoes, such as Lillian's Yellow, come in at midseason, just because those first blossoms manage to pollinate). And it is also historical precedence - seed catalogs have always indicated maturity (and there are lots of people who take pride in coming up with the first ripe anything!).

[Andrey_BY]

I believe the best way to count DTM is from germination to maturity under normal care condition on all stages. This is the most fair and universal system.

[Granny]

I had always understood the date to be from either planting day to harvest or emergence of seedling to harvest. but had a recent discussion with a friend who believes that it refers to plant outside date to harvest. I'm with Andrey on what it "should" mean.

[Andrey_BY]

As far as I know Americans prefer to count DTM from transplanting to the first maturing fruit, but this system doesn't count the age of seedlings before transplantation.

[celticman]

My guess is the the DTM is determined from the seed companies trial (or who ever they got the seed froms trial) generally from transplant of a six to eight week old seedling.
If the seed compnay list DTM as hundred plus days and you live in the north I would shy away from that variety beyond that I grow the plant and see how long it takes in your garden.
Celtic

[Andrey_BY]

There is a significant time difference of 14 days between 6 weeks seedling and 8 weeks seedling which can get you i.e. 65 days (8 weeks from germination to transplant) as DTM from transplant to maturing or 79 days (6 weeks). Of course, the correlation can be not so ideal, but it's only a sample

So your first older seedling should be recognised as mid-early and the second younger seedling will be a midseason or even a mid-late. But they are from the same tomato variety

Try Russian (Eastern European) DTM system=germination>maturity

[cecilsgarden1958]

Interesting discussion.
I never get my tomatoes anywhere close to those dates anyway. I just try to stay away from anything "the catalog" says is more then 80 days.
Strangely, I have had 80 day tomatoes before 60 day tomatoes and I think that is just weird
I do like to check out Territorial's catalog, becasue they used a differant DTM then other catalogs. It's more attune to my area, but they don't carry many I like.

CECIL