Plants Growing in Limestone Basement House Walls

[RichmondPlaceBath]

I have recently moved into a small terrace house in Bath.
The basement level has a light well with significant plant growth in the walls.
They look like a type of daisy along with some ferns.
The stone at basement level is limestone rubble and has had some cement (rather than lime!) mortar repairs.
I will be having the stone cleaned, cement removed and replaced with Lime mortar BUT..
Do I attempt to remove these plants now before they get even bigger in the Spring as it will take several months before I get Listed Building Consent to clean and repair the stone?
The plants are fairly well established into the mortar, with woody stems, if I try and pull them off they break off leaving the roots in the mortar.
Or I best to leave them as they are probably providing nice little habitats for insects?
Any thoughts greatly appreciated, thank-you!

 

[Stevers]

When I repair my garden walls I try to leave the 'ferns' (2nd picture down) and any of the little 'worts', but remove everything else bar toadflax and harebell. Valerian (bottom picture) is a feature of garden walls in limestone country, but has no place in a mortared wall you want to keep as its thick fleshy roots can be very destructive. That daisy (a form of Erigeron I think) although attractive is a fast seeding and spreading thug.

There is a point in the year when the harebells make the most fantastic splash of the very brightest blue after which they can be cut back. The Toadflax is a most attractive little plant requiring a bit of tidying now and again. One would like to think that a bit of wall plant tidying is out of scope for a CO!

 

[RichmondPlaceBath]

Thank-you so much for your advice, I will aim to get the “naughty” plants removed ASAP!
Any ides on a herbicide or weed killer that would not be detrimental to the Bath stone or remaining lime mortar?

 

[Cubist]

Fingers and thumbs or a blow torch if you have one - one of those kitchen brûlée torches will do at a pinch.

 

[RichmondPlaceBath]

Thank-you, Great idea! I have been needing to find a purpose for kitchen blow torch!

 

[Stevers]

Weed killer is optional, the plants you don't want will get the message if you keep pulling out what you can - as long as you do it often enough. Little and often is the way with weeding and garden care in general. A blow torch is better at destroying seed heads than roots though - although I'm told it's still very satisfying.

If you have any sort of garden, a New Zealand box style hot compost heap is a must, as it turns something that can be a nuisance to get rid off into something that's really useful.

 

[LadyArowana]

Quite common to have that happen, in my experience weeding them by pulling often leaves roots behind and they grow back. It’s one of the few times I will use weedkiller, spray it on the leaves, they absorb it into the plant and the whole thing dies. I don’t allow anything to grow on the actual house, on the wall of the lightwell between myself and the neighbour I tolerate ferns or the common thing which has purple flowers late Spring. Incidentally I am also in Bath.

 

[Cubist]

I have been needing to find a purpose for kitchen blow torch!

Me too, but don't tell the First Lady, she hasn't noticed yet that I've snaffled it.

 

[LadyArowana]

Me too, but don't tell the First Lady, she hasn't noticed yet that I've snaffled it.

Aren’t they a bit weak? Surely you need a great big man size blowtorch ?

 

[Cubist]

As you may know from my earlier contributions I'm seldom allowed in the garden without close supervision. So you can think of my brûlée torch as the equivalent of a derringer that can go entirely unnoticed while I act the innocent if found standing over a now brown and crispy ex piece of greenery. I do have to be careful though not to singe my meringues when I pocket the thing.