How many Wisteria is enough for a pergola?

gyells

 Hi, I have a Pergola built in my back garden approximately 6 m long and 3 m deep. It has 4 timber uprights at the front and I have positioned two wisteria plants (one a russelliana and the other a sinensis alba) at the base of the two end Timber uprights. Having a south facing garden the reason I’ve planted these wisteria is to cover the roof side of the Pergola and create well needed shade on sunny days. Having only planted the wisterias last year the cover is of course not that great to date .
I’m now considering whether to put an extra two wisteria plants in and position these at the base of the two middle timber uprights and that is the reason for my question... That given the size of the pergola would the extra two plants be needed to give me sufficient cover from shade or in the future be way too much?! Essentially are the two plants on the ends ample enough or is it worthwhile adding the two extras?

Hostafan1

I'd have planted them in the middle and spread them out in both directions. I'd say 4 is a bit too many.

Lizzie27

I agree with Hostafan, once wisteria gets going it can get to 70 feet (not sure how many metres that would be). They can also be very heavy so you have to think about the weight on the pergola. If you want quicker cover, you could try planting a clematis like "Polish Spirit"  on the middle upright which grows very fast, about 10 ft or so tall and wide, but you can prune this one right down to 1 ft every year so it doesn't get out of hand. 

gyells

Lizzie27 said:

I agree with Hostafan, once wisteria gets going it can get to 70 feet (not sure how many metres that would be). They can also be very heavy so you have to think about the weight on the pergola. If you want quicker cover, you could try planting a clematis like "Polish Spirit"  on the middle upright which grows very fast, about 10 ft or so tall and wide, but you can prune this one right down to 1 ft every year so it doesn't get out of hand. 

Thank you, very good points and will look into the clematis

gyells

Hostafan1 said:

I'd have planted them in the middle and spread them out in both directions. I'd say 4 is a bit too many.

Thank you, agreed that two is enough 

Dave Humby

We have 3 across a similar sized pergola

Valley Gardener

Is that Philadelphus in the back border Dave? You have a beautiful garden!
Gyells I agree with the others four would be too many,I had just one once and the main branch was pretty big in diameter,so I would think weight would definitely be an issue in later years.

Dave Humby

Cagzo said:

Is that Philadelphus in the back border Dave? 

I had to look that up Cagzo 

No, they’re Choisya planted by the previous owner. They seem to do well here.

Fire

I have one plant and it is set on world domination. It will happily fling itself out six metres in every direction, if given the chance. It's a bit of a nightmare, because of where it was planted, maybe 20 years ago (not by me). The sheer amount of leaf it puts out astonishes me every year. One leader creates a jungle, not great for a small garden. I have just given it a serious chop and a serious talking to (very overdue).

Valley Gardener

Thanks Dave,they are on my list as a must have shrub! I got a Philadelphus last week,but no chance to plant it yet.Choisya have a good write up! Nice to see it doing so well in your garden.

Lizzie27

Love the wisteria and choisya Dave - but I didn't realise choisya grow that big either