Understanding coverage of climbing plants

Hi all

I’m looking at possible climbing plants for a trellis on the north side of a fence and top of a pergola but I’m struggling to understand the sizes on the RHS website and how it translates to reality.

Let’s say the section of trellis I want to cover is 3m wide and 3m high and then the top of the pergola is, say, 3m x 5m.

When I look at some climbers on the RHS website they say height of 8-12m and a spread of 0.5-1m. Does this mean that winding it horizontally across the trellis is only get coverage of around 10sqm? Or does tying it in horizontally change the way it might behave?

Essentially I want something to cover the trellis and hide the fence and then over the top to provide some shade.

Thanks in advance!

 

Is the trellis part of the pergola itself?
Sizes are only a guide, because other factors come into play, but if you want to cover that sort of area, you'd need a vigorous climber - ie a rose/clematis/honeysuckle, and you'd train where needed. Horizontally to start with, to cover the trellis, and then tie in across the pergola [assuming it's all one structure] and that's easiest with a plant that's either evergreen, or grows from an existing framework, and produces new stems from the horizontal ones which will then go 'up'. Many roses would do that.
A Group 3 clem, for example, gets cut back early in the year, so you'd be tying in and guiding it for a while, and doing that every year, whereas a Group 2, or something like a C. montana, both grow from an exisiting framework of stems/branches, so less work is needed because the main frame stays in situ once it's all mature enough.
It's often easier to have more than one plant. You could have one for early in the year for the trellis, and something else for later on, on the other side, that will cover the pergola top, to give you some shade through summer. One of the smaller clems for the former, and a large flowered type or a rose for the latter, would be one method.

 

So this is the area. I'd fix 2x1" batten to the "goalposts" near the fence to create a trellis for tying in. On top I have a choice, could to the same, 2x1s or could fix wire across or simmering like that. Most likely it’ll be the 2x1 as that’ll give a bit of instant shade.

I was thinking I would plant at the bottom of the post on the right hand side to climb over the trellis to hide the fence. I could also plant at the base of the near post and climb straight up the post and into the top if you thought 2 plants would be better/necessary @fairygirl

I’d be looking at evergreens just to keep from having a load of leaves to clear up!


Edit: in addition, I’d rather something that stays in place rather than something that gets cut back and regrows each year, particularly for the trellis at the back.

 

Just a thought … I would think twice about evergreens … they don’t retain their leaves permanently … they drop them throughout the year rather than all at once like deciduous plants. I find it easier to have one good clear up a year rather than many every few days throughout the year.

 

Agree with DFA, it's a bit of a misconception that evergreens don't lose their leaves They just don't do it all in one go in autumn....
Having said that, Trachelospermum jasminoides (white or muddy pink flowers) or T. asiaticum (cream flowers) are lovely, vigorous evergreens with scented flowers.
Avoid Fallopia and vines...the first is intent on world domination and grapes, whether edible or ornamental, attract wasps and hornets, as well as making a right mess!

 

Thanks @Dovefromabove & @noisette47 i didn’t really think about evergreens in that way. I guess it explains the eucalyptus that I keep cleaning up after (well, sometimes!)

As for plants, Trachelospermum sounds like a great idea!

 

It largely depends on where the prevailing wind comes from too, and how strong it is. Leaves come off all climbers quite regularly here, so I barely notice it.
I can't remember whereabouts you are @latimer , but some of those jasmines aren't hardy everywhere.

 

@fairygirl I’m in South Bucks, so just NW of London, so relatively warm compared to the rest of the country.

 

Should be ok then @latimer
It's worth adding your location to your profile, so that it's easier for advice.
I've just realised - we had a conversation yesterday bout 'the house'. I'd completely forgotten - d'oh!

 

Ha, you’re right we did, I forgot about that too!

I’ve added in location details, I hope that works!

 

Brilliant!
I'm putting it down to my age @latimer . What's your excuse?

 

Er, well my kids think I behave like an old man, does that count as an excuse?

 

Definitely!

 

One thing to bear in mind when planting is that plants will grow toward the sun.
I have quite a large pergola with 3 x The Garland roses on it.
I planted the roses at the front of the pergola which faces north so they are naturally growing over the pergola toward the southerly aspect and covering the rest of the pergola as they grow.
It makes training and tying-in a lot easier!

There are pigeons everywhere around here and they do roost on the pergola, so there are always lots of droppings below.

Trachelospermum should work very well for you if it gets plenty of sun.
They do lose leaves as the leaves age, but not many.
After flowering they quickly send out masses of new growth that is easy to tie in, but even easier if you can follow my suggestion above.