Wisteria in a pot - help!

In the garden we inherited two years ago there is a wisteria in a large pot growing up the pergola. The first year it flowered well, this year not so much. I know I was lax with feeding it last year, have been more on top of it this year.

However, it doesn’t seem to behave the way all the pruning guides say wisteria grows, I’m guessing because it’s restricted. This year it didn’t really seem to put out many new shoots at all, certainly no rampant whippy growth as is so often described in the books. There doesn’t seem to be much of a framework either, and all the growth is at the ends. There seem to be a few buds on the ends but not anywhere else.

Is it doomed? Should I hard prune it this winter in some way - and if so, how - I can’t make sense of the pruning guides if I don’t have ‘whippy’ growth. Will it reshoot from old wood if I give it lots of TLC? I love wisteria flowers and was thrilled that it was there when we moved in - but I’m worried I’ve killed it through neglect.

 

I think the main issue is the restricted growth space. While they can be grown in pots, they require a lot of care. Is there any way that you can plant it in the ground?

 

Also check that the lower growth isn't coming from below a graft. Wisteria are usually grafted plants and if the rootstock sends out shoots (which mine do, copiously) they will take over from the desired variety.
Agree with BobTG though, ultimately the plant would do much better planted in the ground.
For now, just cut back any new shoots at the top to 2 buds, leaving one or two shoots to train on.

 

@noisette47 Luckily I don't think it is the graft - it's deceptive in the photo but that greenery that looks like it's near the bottom is actually a branch higher up that's bending down. I'm going to prune that off in the winter regardless. It doesn't seem to have put on much new growth, maybe just an inch or two on the tips of the older growth, and that's where all the buds seem to be - so I should prune those newer tips to two buds in winter?

@BobTG The trouble with trying to get it in the ground is that the only viable option to do that is to sink it into the lawn, which is actually situated about 4 foot lower than the patio. So I'd have to prune it extremely hard to even get it off the pergola, and then all the growth is going to be far too low down. Plus, I have no idea how heavy it is!

It's looking like my options are

a) Give it one more chance to see how it flowers in spring (having taken slightly better care of it this summer, and making sure I prune it properly in winter)
b) Attempt to move it into the ground below, including a super hard prune
c) Give it up as a lost cause, take it out and put a new wisteria in the ground below to train up
d) Give it up and buy a new wisteria to put in the pot, accepting that I'll have to rinse and repeat every 5-10 years

What would you do?

 

Given the problem of planting in the ground, could you not do a variation of c) and plant a new one in the ground as well as giving the potted one a lot more care until the new one starts flowering?
Because it's in a pot, it's totally reliant on you for food and water, so will need feeding several times a year and watered regularly (2-3 times a week.) I would also remove as much soil from the pot (without damaging the roots) as possible and replace with John Innes #3 compost, as I expect the old soil is exhausted.

 

I'd do (a). Some things haven't flowered well this yr because sunshine has been in short supply.

I wouldn't do (d). Coping with one already in a pot is one thing. Buying a new plant knowing it will struggle is quite another. Plus wisteria can take a few yrs to flower, so you might get very little reward for your trouble.

 

Ooh that's a brilliant idea! Presumably with the aim of trying to keep the old one going while the new one has a chance to grow up a bit and take over.

The other option is to plant the new one on the other side of the pergola - currently that has spring-flowering clematis in a matching pot, but that would help cover the post until the wisteria gets tall enough.

One question: will a wisteria planted into a lawn cause any issues?

@BobTG I top dressed it with some fresh compost this year but that just seemed to cause issues with drainage. I had a little poke a bit further down earlier and I think the whole thing is basically just one big rootball. I did feed and water it reasonably diligently this year, so it would be nice to see if that paid off at all.

 

Yes, it sounds like the roots have partially blocked the drain hole in the pot and/or the root ball itself is impeding drainage. It can take several years before a newly planted wisteria flowers (15 in my case from a seed!) so it's best to buy new ones already in flower. They are more expensive, but you also get to choose the colour of the flowers.
Edit: Keep and open area about 50cm around the roots and it'll be fine in a lawn. After a few years, you can let the grass grow closer to the stem if you desire.

 

I inherited 2 large wisterias growing in the ground against walls when we moved here. One has a very narrow bed at its feet and the other is just in packed earth and gravel in the driveway. Both are rampant growers and have 2 or 3 flushes of flowers after the main one in spring.

I liked them so much I bought a white flowered one to grow along th efence round our veg plot but then had to keep it in a 60cm pot for a couple of years while we got other priorities sorted out. It limped along and didn't flower again until I got it in the ground and is now also rampant.

They really want to grow so you could, I think, take it off that pergola, cutting off any branches that won't unbend and then take it down to your lawn level and plant it in the ground where it can get its roots down and then thrive. If you can get that done this autumn once it's dropped its leaves it will quickly recover and romp away.

Give the root ball a thorough soak then prepare a hole slightly deeper and much wider than the pot it's in and improve the soil with some organic matter and bonemeal. Plant it at the same depth it was before and water well. Next spring, give it some blood, fish and bone or pelleted chicken manure and watch it grow.

 

@Obelix-Vendée Thanks so much. I will definitely take a close look at the structure when it's lost its leaves and see if that's feasible. I'm just a bit worried that there's no way to unwrap the thick hardened trunk from around the pergola - in which case it would be a lot of butchery to get it down, and then we have to somehow manoeuvre it down the steps. It's good to hear that you think it would quickly recover if we did decide to do that though.