How to Paint a Garden Wall, Step by Step

To paint a garden wall, clean it well, repair the cracks, let it dry, apply primer if needed and give it two coats of paint made for exterior use. The secret is in the preparation. A wall that is badly cleaned or damp will make the paint peel quickly.

What you will need

A stiff-bristle brush or scraper to remove loose paint.
A bucket, water and, if there are algae or mould, a suitable product to kill them.
Exterior repair filler or mortar.
A primer suited to the type of wall.
Exterior paint, a roller for rough surfaces, a brush and a paint tray.
Masking tape and plastic sheeting to protect plants and the ground.

Step 1: clean and scrape

Start by scraping off the paint that is loose. Then brush the wall to remove dust, soil and cobwebs. If there are green or black stains, treat them with an algae and mould product and rinse with water. Let the wall dry well. For walls in the shade, this can take a few days.

Step 2: repair

Look closely at cracks, holes and loose parts of the render. Remove anything that is loose, dampen lightly and fill with a suitable filler or mortar. Smooth it and leave it to dry for the time stated on the packaging. If the wall has large cracks that keep widening, it is worth asking a professional for an opinion, as there may be a structural problem.

Step 3: protect the surroundings

Cover plants with plastic sheeting or old cloths and protect the ground next to the wall. Tape off the points where the wall meets gates, letterboxes or tiles. It is a tedious step, but it saves a lot of cleaning time.

Step 4: primer and paint

If the wall is new, has weak render or has been heavily repaired, apply primer. The primer helps the paint bond and stops the wall absorbing it unevenly. Once it is dry, paint.

Start with the corners and edges, using the brush.
Paint the rest with the roller, in strips from top to bottom.
Do not overwork the paint: apply even coats.
Wait for the time stated between coats.
Apply a second coat for an even colour and better protection.

Important precautions

Avoid painting in direct sun and high heat, because the paint dries too fast and can end up with marks. Do not paint either if it is going to rain in the next few hours. A dry, mild morning is a good choice.

Look at the top of the wall, the coping. If water gets in there, it will run down inside the wall and ruin the paint from the bottom up. If necessary, repair or protect the top with a proper coping.

Walls with damp rising from the ground, with white salt stains at the base, need attention before painting. If you do not fix the source of the damp, the paint will lift again.

Tip: Paint the least visible side first as a test. That way you can see how the colour looks in daylight and how the paint behaves on your wall before you paint the part everyone sees.