Sam,

Thats a great question.. I hope that someone can educate me as well... as I nervously transplanted my baby musa from a 15 inch pot to a 8" pot a few days ago...good question:)

If a pot is too large the plant will use its energy to seek out water and nutrients that will slow down growth above the soil. This could potentially kill the plant if the plant is weak. If the plant is potted in the correct container size then the plant will not have to use unnecessary energy to produce roots.

Feel free to add any other reasons

Banana_fun, what you're saying makes sense. BUT.. wouldn't that be the case if the banana was planted in the ground too?? Or maybe it is an issue of drainage. ?

Here's what I've been told and here's what I've experienced.

Planting a small banana in a larger pot is inviting rot, especially when the plant is young, transplanted, or in stress. Bananas like things wet but only when actively growing.

A small banana likes water, but only so much. Also as part of plant respiration, water evaporates through it's leaves. Let's say you put a 6" tall banana plant in a 5 gallon pot. You water the plant and the dirt in the pot. Now what happens? The banana plant not only has the water it needs, but many times more than what it can ever use. It can't escape the wet dirt that surrounds it because the water is contained in the pot (even with drain holes). It only has so many leaves of a small size that it can't "evaporate" all that water. Eventually...it succombs to rot.

Whereas if you plant a small banana in a smaller pot, it can take the water to the point where the soil starts to lose some of it's moisture, thus letting the roots "breathe" in the dirt. Once the banana grows bigger, you can repot it.

I learned this the hard way, planting small bananas in a large pot. I wondered why they didn't grow and then rotted. I thought, "well the banana is gonna get huge so I better just put it in a big pot now!" But that thinking cost me.

The next baby bananas I put in six inch pots and they are loving it!!! New leaves coming up with no sign of distress...the difference is night and day!!

Zach

Thank you Zach

That is a good explanation.

Using that logic....

I guess it really depends on how much you water, and how fast your soil will dry out. Both things would depend on temperature and drainage.

A small banana planted in a big pot during a cool spring season, probably would rot if it were overwatered. The temps are too cool and like you said the plant can only use so much water.

However the same plant in the same pot might do fine if the soil wasn't overly wet and/or the temperature was hot enough to dry out the soil before things got too soggy.

I guess it just depends on how much you want to monitor the soil in the pot.

Does that make sense?

Hey Zach, thanks for the insight....I truly believe that I did have my Musa in too large of a pot. Its in a 8"now and seems to be happier... however, when will I know to repot it into a bigger pot?

Stacey, you will know when to re-pot when you can pull the plant out of the pot and almost all the soil comes up with it. for your size plant I would estimate about 2-4 weeks at optimal temperature and humidity.

Coniferfreak,
I have put banana pups with little root structure into the ground and the growth essentially stops. Potting up your banana plants when they are young is the difference between 2 foot plants and 10 foot plants by the end of the season. A rigorous fertilizer program during active growth will also help you achieve the best results.

I have 12 sikkimenses seedlings that are 3 weeks old and are 8" high, they were started in nursery plugs and are now in 2.5" pots and will be potted up to 4" pots this weekend. Hopefully 6" pot the week after next and then eventually into the ground from 6" pot.

Sunsetsammy,

You're so right about having to keep a close monitor on the soil moisture. Well draining soil is a must. Still if in a large pot, I worry that either I'll water too little or too much, so I just stick to smaller pots until they grow and then I don't worry so much :)

Zach

Thanks Zach,

Consider myself educated! :)

I have a couple extra bananas this year so maybe I'll do an experiment.

Soil physics in a pot is dramatically different than in the ground.

In the ground, the Earth provides drainage. In a pot, it depends on the substrate among other things.

Bottom line: drainage in a pot is generally much weaker than in the ground. So if there is excess soil in a pot, it ends up remaining moist which can lead to rot. In the ground it's usually not an issue.

When the roots take up most of the volume in a pot, there is no excess moisture because it gets absorbed by the plant. This also requires much more frequent watering than if in the ground.

There's your answer, in a simplified manner. There are of course many other factors to consider that are beyond the scope of this post but there is lots of excellent info on these forums if you search.

And if you use too a big of a pot it's too hard to move it around. LOL....

you can also buy a fairly inexpensive moisture probe to see what is going on inside the pot.Laarge pots appear to be all dried out on the top, but can be very moist about 8 inches down.I also do not use the water holding saucers that come with pots.Indoors I use a saucer much bigger than the pot so I can see the water drain out the bottom.