How can I remove the orange stains left by grass weed and feed?

Question

Last weekend I covered our garden in grass weed and feed, specifically EverGreen 360sqm Complete 4-in-1 Lawn Care, Lawn Food, Weed and Moss Killer Bag available here.

It has rained every day since but today is a very hot day. I woke up this morning and noticed that the paving slabs (stepping stones) that run across our garden have now been stained orange and even our tarmac driveway has patches of orange stains - both look horrible.

I've tried washing both down with a pressure washer but that didn't do much. What are these orange stains and how can I remove them?

I'll upload a picture of it helps.

Answer 1

I had the same problem, i put (llawn feed & weed kill) down very carefully on wet ground with it raining to help soak it straight into the ground. But in the night a cat had walked across the grass and onto my steps and patio leaving rusty coloured foot prints plus some rusty coloured splash drops had somehow managed to get onto the slabs as well. I use patio magic which always bring my patio stabs up like brand new but would not shift the stains. I read that lemon (not juice) works, so i cut 3 lemons into chunks and wiped up and down on stain and using old toothbrush to scrub stain, after wash off with water (do not allow to dry or leave on to long or you will have a lighter mark instead of rust coloured one!) But it worked!! one or two bits need another going over again but couldn't believe it. Also read white cider vinegar does the same but remember wash of straight away!! Otherwise you will have to lighten the whole patio area to match if you end up with patches of light stains!

Answer 2

To some extent, it depends on what the stepping stones are made of - some cleaners are suitable for concrete paving slabs and not for natural stone. The stains will have been caused by the iron content in the fertilizer within the Evergreen product. This staining can be because you managed to get some on top of the slabs and didn't remove it immediately, but also occurs from the bottom up, that is, when the lawn is wet from rain or you watering it, the fertilizer starts to dissolve, and may penetrate the underside of the slabs as well as the top as a solution in the water. If you've had a lot of rain, its likely both top and bottom of the stones have been soaking up the solution.

You can try the following types of product, but the truth is, if the fertilizer in the product you used is a slow release type, that could take anything up to 4 months to degrade, which means the staining may actually get worse during that time, and any efforts you make to remove the stains might be best left until you know the fertilizer is no longer active. The first link is to a product for concrete paving which may or may not be suitable for natural stone

http://www.theruststore.com/How-Do-I-Remove-Rust-Stains-Caused-By-Fertilizer-W44.aspx

And this one is for natural stone paving: Lithofin BER1 BERO Rust Remover and Stone Cleaner, available at Amazon in the UK, not sure about anywhere else, link below

http://www.amazon.co.uk/Lithofin-BER1-Remover-Stone-Cleaner/dp/B000WXTVUU/ref=sr_1_1?ie=UTF8&qid=1439119220&sr=8-1&keywords=lithofin+bero

Regarding the tarmac, the staining might just disappear on its own, but I found this - its aimed at removing battery acid stains, but may well work to clean the tarmac - might also deal with the staining on the stones

http://www.front9restoration.com/products/f9b-a-r-c/

All these products must not be allowed to leach onto planted areas, including your lawn - they'll kill the grass, so you'd probably need to lift the stones and treat them, then replace.

Answer 3

I know this is an old post but I have found a solution, I have just done exactly the same, it rained and I stupidly walked over my cement paving. Googled lots of ideas but decided to try something I already had at home, lemon juice directly onto rust mark followed by bicarbonate of soda then scrub with a wire brush, even brought out the lichen from an overhanging tree.