Easier for the gardener yes, but not best for the plants. ;) You'll find many discussions on this here that a search will pull up for you but in a nutshell, the purpose of transplanting seedings is to stimulate root development - to force the plant to develop the fine fibrous roots rather than just a few larger ones or one tap root. Fibrous roots are the real nutrient feeders.

That is why the ones you buy at the nursery have such extensive root systems - they have been transplanted 2-3 times before you buy them. They are NOT sold in the same containers they were germinated in. ;)

And another great benefit of transplanting is so one can transplant the seedlings deeper - to just below the cotyledons. Seeds are planted so shallowly for germination that the majority of the plant is above the soil line, easily uprooted or damaged. Deep transplanting not only supports the stem, prevents leggy plants, but for many plants it also stimulates roots to develop all along the buried stem. This is especially important for all woody stem vegetables and flowers.

Also many of us who grow a great many plants from seed use germination trays, not cell packs, for germination. It saves soil, allows for better soil heating, and improves germination 10 fold. 100's of seeds may be germinated in 1 tray but then have to be transplanted for growing on.

Lastly, supplemental feeding of seedlings isn't as beneficial as transplanting them to a good soil-less mix because the roots are not sufficiently developed to insure adequate uptake of nutrients before it can leach out of the soil due to watering.

So, for the strongest, healthiest plants most will recommend at least 1, preferably 2 transplants before going to the garden.

Hope this helps. ;)

Dave

Here is a link that might be useful: Staged transplanting discussions...

Digdirt: that's an intelligent and helpful post. It will spur me on to make it out to the greenhouse today after work to transplant those seedlings that are still languishing in their original seed-trays. Thanks!

Hi Dave,

Thank you for your response. It was very helpful and what you wrote makes a lot of sense. Do you know what prevents plants from forming extensive roots in the germination cell? From what I have seen so far, I don't think limited space is the issue. Also, since in nature seeds sprout pretty much where they fall and no one is there to poke them deeper in the ground, how come those plants develop fine? Life in the outside world is probably a lot harsher I would think. I'm just really curious and haven't found a satisfying answer yet. Would like to hear your thoughts if you have some time.

Thanks,
Amna

Do you know what prevents plants from forming extensive roots in the germination cell?

It depends on how technical you want to get. ;) A detailed scientific article is linked below but please note that it is still in development - accurate but work still needed. Also, this article is one of the many sources already linked in the discussions I linked for you above.

Basically it boils down to (1) the type of cells found in the different types of roots. Initial roots contain only the cellular structure imposed on them by the seed embryo DNA. And (2) when, in the growing process, the fibrous root cell development is triggered - true leaf emergence. Stage transplanting magnifies that triggering by providing a new growing environment and a deeper environment that forces additional fibrous roots to develop along the now buried stem.

Plants left to go along in their germination cell will, eventually, develop the needed fibrous roots, but not as quickly nor to the same degree. The article linked above shows you pics of the root development on transplants vs. non-transplants.

Also, since in nature seeds sprout pretty much where they fall and no one is there to poke them deeper in the ground, how come those plants develop fine?

Apples and oranges to a degree as the goals are so different. ;)

First, while some seeds in the wild may indeed sprout where they fall, the parent plant "planted" (scattered) thousands of seeds. Of those thousands how many germinated? Studies using both wildflowers and trees show less than 10%.

Second, of those that did sprout, their survival rate is quite low - less than 20% - not something we want when germinating for the garden. Only those very few that chance allows to fall in just the right place with just the right soil, just a lucky wind that covers it or a wild creature poops on it, the right nutrients, sun exposure, and moisture will ever grow to compete with its parent.

Hope this helps.

Dave

Here is a link that might be useful: How Plants Devlop Roots