Do i need more than one of these for hedge?

Spender£

I have seen this plant as a hedge on the perimeter of a large factory and i notice it is quite a beast with huge thorns and spikey leaves, after research i found it to be Berberis Juilianae (Chinese barberry).
I would love to grow this at my elderly mums house under her window as she worries about people getting through the window in her back garden, does anybody know how many to form a 3 meter hedge, I read that it will spread around 3-4 meters so is it possible to make a hedge out of one plant or does it need to be two, i saw another article claiming it should be planted 50 cm apart so I'm not sure how to play it.

theoretica

A lot will depend on how soon you want a 3m hedge.  A plant the size of the one you picture would likely get to 3m - in maybe 10 years - but it will get there much faster if you plant 6 or so!

twopenny

Someone's going to have to prune it.

And clean the window.

Berberis if very good and easier to deal with. It has lovely flowers and berries for the birds.

You'd still need a few depending on the length of the window. I've seen them grown all around windows but mostly just underneath.

The quickest growing is a rose. Blush Noisette will grow fast and dense with highly scented roses most of the year

Davesnave

Short answer is 6 will do it planted 45 cm apart. They will need an annual trim for height and spread.

As 2p says, cleaning the window may need more thought and kit than you'd normally use.

There are prettier berberis that still have spines, but beauty is in the eye of the beholder and these ought to make place like Fort Knox!

goldfinches

There is an edible variety or maybe they all are I'm not sure about that as I haven't gone into it in any great detail but I have seen these for sale Dried Barberries | Ottolenghi.co.uk | Buy Online so you may find some varieties are very MSE and your mum could sell her annual crop.

theoretica

An alternative which might do the job and less likely to grow too big and need much pruning (leaving thorny cuttings) is rosa rugosa.

Farway

theoretica said:

An alternative which might do the job and less likely to grow too big and need much pruning (leaving thorny cuttings) is rosa rugosa.

An nice easy one this, and a plus is should it require keeping in check the only thinking required is "where are my shears / chainsaw"? as good hack will sort it without long term harm