Paulownia Tomentosa - when to plant out & success with seeds?

I have just bought 60cm potted plants (they are just bare stalk at the moment) and wanted to get advice on when to plant them out please? I live in Derbyshire and it's damn cold at the moment, although no snow ....not yet anyway.

• Also with them being 60cm already, how much growth can I expect in their first season?
• I don't wish to cut them back in the autumn - is that ok?
• If I don't cut them back, are they likely to grow even taller the following year?
• Will I need to give them frost protection during their next winter?
  
• Can I grow new plants from seed? (I have also bought seeds)
• If I can grow them from seed, how easy is to germinate the seeds?
• From seed, how tall does the plant have to be before it can go in the ground?

Many thanks.

 

Hi Derbyshire

I have to say that I have no idea of the answers and no experience of Pawlonia. But it has been on my 'of interest' list for some time. Hopefully someone will have experience of it, otherwise I suggest you Google it and read lots of sites - not just one. Sites sometimes have conflicting information and I like to read up to 20 sites and then take the average.

It looks a beautiful thing and is said to be fully hardy. However I have never seen it growing - and I wonder why. Is there more to it than we know?

I would be tempted to keep it inside the house, or in a frost free environment until the frosts are over - about April. You can then plant it out and it will have a full season to gather strength before next winter. If it has no leaves now, give it very little water - without leaves it doesn't need (ie can't use) water. Just ensure the soil is very slightly moist to prevent it totally drying out.

The internet suggests it can grow up to 25 feet or more - so yes it will continue to grow, but I am not sure how fast. It is a tree and can be treated like a tree - ie by not cutting it back. However you can cut many trees back - its called coppicing. This makes them grow more shoots from a low level - and it appears that you can do that with Paulownia. But it might be worth getting it well established and up to a few feet before starting.

You should be able to grow it from seed. Its worth Googling 'Paulownia seeds' to find the conditions. But remember its a tree and trees can take several years before they become adult and capable of producing flowers. It appears that it can take from 8 to 10 years to flower. If your potted plant is a cutting from an adult plant it could flower much earlier, but I suspect that at that price it might just be a seedling.

Lets hope someone has experience, but in the meantime you can learn a lot from Googling. That's all that I have done. Try
http://apps.rhs.org.uk/plantselector/plant?plantid=1388
http://www.gardenersworld.com/plants/paulownia-tomentosa/2534.html
http://apps.kew.org/trees/?page_id=128
http://www.seedaholic.com/paulownia-tomentosa-foxglove-tree.html

 

Paulownia is hardy, but perhaps wait for end of Feb (later if weather is wintry then) your plantt is small. probably best not to Stool it for 2 years. Mine grew really quickly in the first year (wet year, plus gave it some fertiliser) so I stooled it second-Spring, but 3rd Spring probably more likely. Perhaps wait until it has made at least 5', and a reasonable girth, before its first chop?

Normally only a single stem is allowed to grow (after cutting back). I "rub out" any other side shoots that break. So you will be looking at a single, straight, leafless-stem all winter. If you are OK with that then cut back in early Spring, before buds begin to swell, so that all energy goes into that one leading bud. Some people prefer to cut back in Autumn so as not to look at the "dead twig". Either is fine.

if you meant "you don't want to cut it back at all" then that's fine. It makes a nice tree.

Yup, Paulownia is a tree. Allowed to grow (into a tree) it will then bear nice flowers. But for really big leaves you need to cut it back, and only allow a single stem to grow (which will do 8' - 10' in a season)

Yup, I found it easy from [bought] seed. Haven't grown any to flowering size to try my own seed as yet

Up to you I expect. It will probably come on faster if you give it some Autumn/Winter/Spring shelter, e.g. in an unheated greenhouse, for the first couple of years - that might save you a year to maturity. It might reduce its subsequent hardiness, but I think there is close to zero chance of that - its hardy enough in the first place, if it was, say, a Eucalyptus I'd be keen to give it more exposure to cold when young.

 

If you leave two stems to grow each year then you get middle-sized leaves rather than enormous ones, and more of them.

I think you would be best planting in late March when the worst of the weather will be over. (Don't even think about Spring 3013.) I can't see the advantage of keeping it in a pot longer term, it would be better off getting its roots down into the ground while it is still small. I think I would wait till the following spring to stool it.

I tried seed but failed completely.

If it is not stooled every year it would rapidly make a large shrub and then a tree. Perhaps this is why it hasn't caught on as a universally popular plant - people are intimidated by the care plan. Unnecessarily, in my view.

 

Meant to post a picture of mine, earlier.

October - 1st season after initial planting in the Spring (its on the left side of the photo)



Year 2 - stooled in late Winter, photo taken in October plant was 3.10M tall (Banana has grown a bit and all!)


and single leaf (2nd season):

 

That IS impressive! Thanks all for the superb advice.

 

Ermmm....it was a superb, mild and sunny day today...and I.....ermmm........forgot to come back on here to check for replies and instead went at the garden full throttle and whilst in the swing of things I planted the 2 Paulownias. I just hope they fare ok. Should I protect the base of the trees with some hay or any other warming material?

 

I don't think its necessary. They re hardy. If the plants are very small, and have not been acclimatised to being outside then "maybe", otherwise I very much doubt it - and you may encourage them to be cosy and start into leaf early.

If we get some bitterly cold weather (below -5C say, or if days do not go above 0C) than perhaps provide some protection then, but not as long as it remains mild