My guess...

In the natural order of things, "the strong dominate" so that the roots of the radishes will be small, but a few of the plants will produce viable seed. Likewise, the tomatoes will be stunted and any fruit you get will be small. These plants will be competing with one another for water, air, sunlight and nutrients.

If humans hadn't intervened in Nature, we certainly would not now have ipads, automobiles and skyscrappers. Plus we might have been NATURALLY selected against and earthworms (say) might be ruling the planet.

Thin these plants...your plan will not produce a harvest "fit for modern man"

or simply because the harvest quantity/quality won't be as good?

That is the primary reason. But if you have the room and aren't that concerned about the amount or the quality of the production then let them go as is and see what happens. It is one of the best ways to learn.

Tomatoes, if what went to seed were hybrids, will revert to parent stock and likely have several cross-pollinated weirdos on them.

Be sure to report back on the results.

Dave

Is it too late to vote for the earthworms?

We actually don't have a lot of room so experimenting isn't really an option. As for the tomatoes, that was my first thought, as we had planted a bunch of different kinds last year, as well as peppers, which I understand being the same species will make the seeds impure.

I guess that people living in crowded conditions will react in much the same way - struggling for resources and not becoming plump and delicious. Unless of course you live in a first world city that exploits the resources of ... Oh, I'll save it. :)

Thanks for your thoughts, much appreciated.
Marc

Marc, for what it is worth, tomatoes and peppers are not only different species, but different genus as well. (Solanum vs. Capsicum) The title of your thread made me laugh. Cheers!

Thinning seedlings is absolutely necessary in many areas.

It improves yield via lowered competition for resources and it reduces disease/pest pressure.

Some people can get away with having huge walls of stressed plants without pests/disease showing up, but in my area you're playing with fire with both warm and cool season crops, especially with the humidity and seasonal bug patterns. It doesn't take much for a "bad" fungus to find a home around here with proper conditions for it to cultivate.

Some stuff can handle being crowded better than others...around here okra can be crowded very tightly (though aphids will find it), but if you do it with squash/toms you're gambling with the possibility of a very fast moving disease.

Wind moving through the leaves of plants in high pressure times of year can be just as important as proper moisture and fertilization.

Besides, all you need to thin is a pair of scissors and crouching/moving through your garden to thin. It's not that much work unless you planted massive amounts of stuff.

Yeah, as has been said there is a finite amount of sunlight and nutrients in any given area. The more plants in that area, the more those limited resources are divided between them.

While there is an upper limit on how much a single plant can use, the more you crowd in together the faster you reach the point where no single plant is getting their fill, and they will be smaller and less productive as a result.

If we factor pests and diseases into the equation it seems to me that the plants *do* require us for their survival, in which case the relationship is mutually beneficial and not just a case of humans molding plant life to suit our requirements.

After this discussion I've decided that I'm going to thin them out. In previous years I've let them fight amongst themselves and noticed that the results were far from abundant, and the main purposes of my garden are to eat and learn, so thanks for helping with the second one (and hopefully the first as well).

A lot of what we consider vegetables are extreme mutants selected over the years.

Plants aren't supposed to put out mega-tomatoes. There's no evolutionary advantage to something so big a bird/animal has to eat a ton of flesh in order to get to the seeds they later distribute. They grow cultivated in most areas at a time of year where food for birds/animals is very abundant, too.

We ask many of our vegetable plants to put out extreme amounts of production, especially given the push for small/bush/dwarf plants that still produce well.

Breeding has also led to the insertion of genes (naturally via breeding) which help balance out some of the pressure of the mutants. Oddly (or not) a lot of these genes come from wild plants growing in areas which produce undesirable fruit, but show great disease/deficiency resistance.

Less thinning means less disturbance to the roots of the seedlings you want to keep, and less chance of disease getting in through the loosened soil. I'm a bit lazy, so I use a seed sava as it reduces wastage and cuts down the time I spend thinning plants out later on.

Wow djohn24 if seedlings get stressed by being thinned they would not last long in my parts. :)
Also much easier for everyone concerned to use sharp little scissors and some time for thinning those you do not want, or have room for.
Seperating my tomato seedlings seemed to stimulate them more than anything. Someone has a link to a video of a man seperating his seedlings, it really opened my eyes to how tough they are.

I just had to chime in and say, That I watched a show on corn awhile back and it said that with out humans around to thin and space them out corn would likely go extinct within three years

Each crop has an optimum spacing for best yield -- not too crowded, not too sparse, but just right. Proper spacing can be achieved in several ways:

a.) Plant seeds at proper spacing to begin with. This works well with large seeds such as beans but results in uneven spacing with small seeds..

b.) Plant seeds somewhat thickly, then thin to proper spacing. This requires a little extra seed and the willpower to thin ruthlessly.

c.) Plant seeds somewhat thickly, then transplant the seedlings at proper spacing. This is economical and results in a tidy garden.

Jim