How can I protect my painted window sill from water?

If that is a picture of you window sill, it is rather deep. Congrats to you for that. You could buy a piece of gutter to use to set the plants in, so that the water doesn't leak out. Or they make a Flex Seal in white that you could paint on the sill.

As long as you have saucers under them you should be ok, but the orchids could use a misting once in a while, that could over time damage it. If you are that worried, perhaps you could use a marine polyurethane , a few coats, to prevent water damage. You shouldn't need saucers for your orchids if they are in decorative pots. As long as you are careful when you water to get the water only on the soil, and not on the leaves, you shouldn't have water problems on your paint.

A coat of oil base paint will give protection from most leaks. Wipe sill each time you water and give plants a 1/4 turn to avoid the plants leaning toward the sun. You might want to check light requirements on your plants. Not all do well in bright light. I see aloe looks a little droopy and one of the other plants has some yellowing leaves?

Cut glass to fit in sill. Set your plants on some tile.

Put car polish on the sill. water should bead up!

I use a lot of terracotta and antique plates under my plants. They are porous or often crazed, so I use plastic lids that are 1/2 the size of the saucers to elevate them. It works to keep any condensation off my wood furniture & sills, and they are shallow, so they are very stable.

I set my terracotta pots on white ceramic tile.

Measure your window sill and see what you can find in a similar size at Home depot(etc).

It's been working for me for a year or so with no problems.

Best of luck.

I have a similar issue with the plants during misting and watering from the water can. I had Been thinking of this plastic sheeting menards sells. It's sticky on the back usually for protecting carpet during painting.

Thanks for all the suggestions. I definitely will see what happens. Right now, the plants sit on the dining room table. I will deal with this after Christmas!

I put a heavy gage plastic from a fabric store under mine. That way, it is protected from water.

Find an old metal baking tray that is the size you need. You could paint that any color you want but the best part is that it would catch any water that over flows.

i had a small metal baking tray under a couple plants. When water overflowed onto windowsill, it went under the tray and rusted. Now I can’t get the rust off the windowsill.

we have wide painted white windowsills, and it’s rained in a couple times and wood is starting to warp. Looking for a waterproof substance to put on sills. My other windowsills have plants that I water and I inevitably spill water on. Help!!

Buy a Plant tray to fit the window from a Plant or Garden /centre.

Use a coat or two of an oil based paint. That is what is recommended in bathrooms since it is better at repealing water but it isn't water proof.

I tiled my window sills with porcelain tiles. I went to Floor and Decor but Home Depot and Lowes sells nice tiles. It is an easy project and makes watering and cleaning up easy peasy.