Something like this is is the look I'm going for.

I'd say just continually pinch off the sprout-tips after they grow a foot or so during the growing season. Understand after a couple years you'll have to more severely cut it back because even the pinching won't prevent it from becoming a bigger and bigger tree.

how about a pic of it today .. rather than the pic in 5 years ...

when did you start the seed ..

if you pinch too early.. you may end up with a shrub ... rather than the tree form shown ...

promise us.. if you leave the property ... you will kill it first since the new owner may not appreciate its potential problems ...

tree time is counted in decades .. i hope you appreciate what fast means.. within that realm ....

ken

Research coppicing of Paulownias. That is how they are kept to a manageable height, eliminates the potential for flowering and seeding and increases the foliage size. Short, stubby plant = BIG leaves.

That would produce the big leaves but coppicing wouldn’t give the OP a metre of clear, single stem. For that you’d need to pollard at the trunk height required.

Hi @ken_adrian Adrian MI cold Z5

Rest assured, yes, I can easily promise that. This tree will live his whole life in a container, like my other trees and all my plants. If I move one day, my dear plants will move with me, but I am in my current location for many years to come.

Perhaps my question was a bit premature, but I was curious. The tree is still a baby, only a month old, and is growing extremely fast compared to any other tree I've got. I started citrus and apricot from seed but I've never seen anything grow as fast as this Paulownia.

As I understand, Paulownia can grow up to 4m per year. In a container I expect it will be less, but still it seems reasonable to think it could reach a decent height by the summer, and hopefully help with shading.

Edit: Yes I know, this is a tiny pot. This windowsill is where I start my plants before they graduate to big pots on the roof.

"This tree will live his whole life in a container, like my other trees and all my plants."

Put something root proof under the container and don't allow a smidgen of root to poke out and touch the earth.

The invasiveness is not just due to seeds- it's the roots. Those roots will travel, and when you yank the pot free and break them they'll panic and start sending up about a million little shoots that you'll be dealing with for YEARS. Repeat- years.

I have never seen such a tenacious bunch of root shoots in my life.

Hi @cearbhaill (zone 6b Eastern Kentucky)

Thanks for your comment.

My garden is on a rooftop, where there's no soil anywhere outside the containers, so no risk of invasiveness via roots. The containers themselves are on feet, so I can easily check for anything poking out. The containers also have a tray under their feet, so I don't have to worry about some rogue root sneaking out and damaging the roof itself either.

The reason I chose Fortunei over Tomentosa was that it was supposedly less invasive: so please be assured that I am not taking Paulownia's invasiveness lightly. I will be watching closely, and especially for flowers.

Paulownia Fortunei is not considered invasive. Only the Paulownia Tomentosa is considered invasive. The hysteria surrounding these plants is largely unjustified. Regardless of how much you prune in the first year ( within reason) it should send up a straight stalk in the second year. Most paulownias spend the majority of their first year building out a root system.

Isn't OP in Malta?

@HU-645340990

Yes, that was my reasoning for choosing the Fortunei type: I intentionally chose this one because it isn't invasive like the Tomentosa, or at least, a lot less. Thank you for noticing that, everyone seems to just stop at the Paulownia part!

I have repotted it twice since starting this thread, and I can certainly see that the root growth is extremely impressive! I will need to root prune this one yearly in the future, at a minimum.

For the time being the plant is still indoors so no risk of invading anything yet anyway, but I'm thinking of moving him up to the roof in another month or so.

@gardengal48 (PNW Z8/9) @floral_uk z.8/9 SW UK

You are correct, I am in Malta (zone 11). I will get around to adding that to my username sometime! I should have put that info in the OP.

Paulownia is not native to here, for sure, but it's not subject to any laws either. I checked before importing the seeds. And I purposely chose Fortunei NOT Tomentosa, precisely because it is less invasive.

Once he moves to the roof, he will have to face the scorching Malta sun and the salty winds which reach gale force on a regular basis. Not all trees can handle it. But Paulownia is supposed to be tough so I hope he can take it.

The container will definitely keep him from getting invasive via roots, but it doesn't solve the problem of seeds. However, depending on the sources, people report that Paulownia don't flower for at least the first three or four years, with some sources saying they can take up to fifteen years to flower. So, not a problem in the immediate future. I will worry about that if it survives the heat and wind!

I do realize that this project might seem like I am trying to tame a kraken, but he will have to face some tough conditions up on the roof, and if it gets out of control I will not hesitate to destroy the plant.

If you keep cutting back or pollarding/coppicing each year, it will not flower. But the leaves will get even larger than normal. It does require a degree of maturity to flower - 8-10 years is typical but it could take as long as 15. And it does not flower reliably in maritime climates with their typically cooler summers. And location is a key factor when considering any invasive - what is invasive in one location may not be in another. Paulownias are not invasive here!

Just a word of warning....due to the size of the foliage, it does not tolerate winds well.....winds tend to chew up the foliage.

Thank you @gardengal48 (PNW Z8/9)

You are right about your warning, I hope it will do ok up there.

From prior testing, I know that it's hit or miss with the large-leaf plants here: my two fig trees are extremely unhappy and will probably need to go in a few months, but the grape-vine (goblet trained) seems to not mind the wind at all. I will see soon enough how the Paulownia leaves handle it! But I definitely wouldn't be surprised if they get damaged.

Quick update to show some pics.

The seed germinated on September 8th 2021, so this little Paulownia is six months old today. 🎂

Note: I don't use the growlights all the time, just when it's rainy or cloudy like it was today.

He's been in three sizes of Lechuza (or similar) self-watering pots, with my local garden center's homemade "indoor plant mix". Next month he will move to the roof, to a non self-watering pot, with the same soil mix I use for my other potted trees (Stender peat-free potted plant mix + a heavy dose of extra perlite, Seramis and pumice).