Will concrete wall suck moisture from soil?

[CubanBenny]

I am planting vegetables in a tin border against a concrete wall .It is one of the last parts of my garden where no vegetables/flowers are growing ;-). However I am concerned with the wall drying out the soil -

I have heard a wall will suck moisture from the earth - Is this true? If so, I can put a polypropylene sheet between the wall and the earth. I will mulch it too, i'm sure that will help.

[Cadalot]

Yes Masonry and Concrete will absorb water.

[nickdub]

borders against a wall are nearly always dry but warm - this is mainly due to the rain-shadow effect of the wall.

One way to take advantage of this, is to grow stuff which enjoys this set of conditions eg peaches, grapes or figs.

[burnie]

How old is the concrete, I worry about chemicals leaching into the soil too, I grow non edibles in that situation for a bit till all calms down.

[CubanBenny]

How old is the concrete, I worry about chemicals leaching into the soil too, I grow non edibles in that situation for a bit till all calms down.

It's about ten years old, and it's painted. It's not exactly a wall - It's a fence with concrete posts and concrete bases for the wooden fence panels to rest on.

[CubanBenny]

borders against a wall are nearly always dry but warm - this is mainly due to the rain-shadow effect of the wall.

One way to take advantage of this, is to grow stuff which enjoys this set of conditions eg peaches, grapes or figs.

Unfortunately it's an east facing wall, so I don't think in would be sunny enough to grow any of these, Mediterranean type plants well.

[Penellype]

I have concrete fence posts and gravel boards down the sunny side of my garden and I must admit I hadn't given it a thought. My tomatoes grow fine against the fence as do peas if I plant them there.

If you are worried why not grow veg in pots against the fence. Plenty of veg will grow really well in large containers and you can move things about easily that way. If you want something bigger, a blueberry bush is quite attractive and a container is a good option for these as they like acid soil.

[nickdub]

Probably try a choice dessert variety of plum in that situation and fan train it - can be a real work of art, as long as you have the patience. something like Jefferson's Gage or Kirke's Blue would be examples.

[CubanBenny]

I have concrete fence posts and gravel boards down the sunny side of my garden and I must admit I hadn't given it a thought. My tomatoes grow fine against the fence as do peas if I plant them there.

If you are worried why not grow veg in pots against the fence. Plenty of veg will grow really well in large containers and you can move things about easily that way. If you want something bigger, a blueberry bush is quite attractive and a container is a good option for these as they like acid soil.

Thanks for the suggestion of the pots - I was thinking of pushing some corrugated plastic sheets between the concrete and the soil so as the concrete wouldn't be able to absorb water. Bit like pots I guess.

[Potstubsdustbins]

Things will be OK the amount of concrete round a fence post will make very little, if any difference to water retention especially at 10 years old.

[Potstubsdustbins]

As to nasties leeching into the soil, first you need nasties.

The type of concrete used for fence posts is very basic consisting of aggregates i.e. stones, a small amount of sand, water and with a binder of cement.

Cement consists of silicates derived form clays and shale's, usually derived as a by-product of lime stone quarrying and calcium of carbonate i. e. milled lime stone. It can be a skin irritant whilst dry and if you are susceptible but otherwise nothing to worry about.

[Kirk]

Not sure a wall absorbs moisture to any extent, if it did the moisture would by definition have to go into the wall and in effect soften it. So what happens to buildings when it rains? All those '60s concrete car parks are still an eyesore and still standing rock solid.

I would say a wall creates a rain shadow, where the rain just does not manages to strike the ground at the right angle so it remains dry. You can often see this on a rainy day, the band close to a wall will be dry on one side of a road. Also any heating of the wall by the sun will cause greater evaporation of moisture in the ground close to it.

Easy thing is to find something that will tolerate the conditions, and if you work out what let me know as I have a wall where the ground is also dry and could do with a more tolerant veg.

I do on mine have the option fo an electric drill and a few holes in the guttering above it that would allow any rain to drop through.

[vixylix]

My beds are all against either walls, or concrete fence posts (all old) - I've not noticed a problem with them drying out - they're a meter deep, so I guess the majority is quite far away from the wall. I wouldn't worry too much if I was you

[CubanBenny]

Easy thing is to find something that will tolerate the conditions, and if you work out what let me know as I have a wall where the ground is also dry and could do with a more tolerant veg.

Yes, will let you know. I am going to start with veg I know of which do well in cooler dryer conditions - rhubarb, swiss chard, peas and blackberries. I might try Jeruselum artichoke or something in Squash family. Although that is for next year, for my autumn veg I will just need to water in a lot.

[Penellype]

Buckets/bags of potatoes are good against a wall. In the spring the wall acts like a storage heater so you get a degree or so less cooling which helps keep the frost off.