How to tell if you are overwatering your plants

March 7, 2025

Too much water and not enough water look almost the same from a distance, which is why overwatering catches so many of us out, and I include myself in that, because the pots by my back door are the ones I kill most often. The plant droops, we read the droop as thirst, we water it again, and the roots go backwards a bit further. So the skill worth having isn't watering, it's reading the soil before you water.

What an overwatered plant actually looks like

A plant can't tell you it's had enough, so it shows you instead, and these are the signs worth knowing.

Soft, drooping leaves. A thirsty plant droops with crisp leaves and an overwatered one droops with limp ones, and that difference is the quickest tell you have.
Yellowing from the bottom up. Older leaves down near the base going yellow while the new growth stays green usually means the roots are sitting in water.
Dark, mushy roots. Healthy roots are firm and pale, so roots that are brown and squishy and smell a bit sour have gone to root rot.
Green or white growth on the soil surface. Soil that never gets a chance to dry out will grow algae and mould across the top of it.
Fungus gnats. Little dark flies that drift up out of the pot when you knock it. They breed in permanently wet mix, so they're a symptom rather than the actual problem.

Thrips cop the blame for that last one fairly often and they shouldn't, because thrips prefer it hot and dry. If the flies are coming up out of the soil, they're gnats, and the soil is too wet.

How to check before you water

The whole thing comes down to one habit, which is checking the soil instead of checking the calendar. Push a finger into the soil about 5cm, and if it's dry at that depth you can water, and if it's still damp you leave it alone and come back tomorrow. With a pot there's a second check that's even quicker, because you can lift it. A pot that's still heavy has water in it. A pot that feels light for its size is ready for a drink.

If you'd rather not go by feel, a soil moisture meter takes the argument out of it. You push the probe in, read the dial, and water on what it says instead of on what the leaves look like. They're a few dollars and they're the cheapest way I know to stop guessing.

Watering so it doesn't happen again

Water in the morning. The soil gets a chance to take it up before the heat arrives, and the surface dries off during the day rather than staying wet all night.
Deep and less often. A long soak that wets the whole root zone pulls roots downward, and a daily splash keeps them sitting near the surface where they dry out first.
Water at the base, not over the leaves. Wet foliage overnight is how a lot of fungal problems start, so put the water where the roots are.
Sort the drainage out. Pots need a hole that actually drains and a saucer that gets emptied, and a garden bed that stays boggy after rain needs compost and gypsum through it rather than more water.

What to do if you've already overdone it

Stop watering and let it dry back. This is the hard one, because doing nothing feels like giving up on the plant, and it's the thing that actually helps.
Move it somewhere with a bit of air. A breezy spot out of hard sun dries the soil far faster than a still corner will.
Look at the roots. Tip a potted plant out, trim off anything brown and mushy with clean secateurs, and repot into fresh mix.
Fix the mix, not the watering can. If the soil holds water like a sponge, open it up with compost and a coarser mix, because you'll be fighting it otherwise every time it rains.

Shop related products

Brunnings Ultimate Garden Soil 30L. A bagged soil to open up a bed that stays wet too long.
Naturally Good Mushroom Compost 25L. Works organic matter through heavy soil so water can move instead of sitting.
Brunnings Garden Compost with Seaweed 25L. Compost with seaweed in it, for beds that need structure rather than feeding.
Easy Wetta Garden Mulch 50L. Mulch slows evaporation, so you water less often and the soil dries more evenly.

Did you know we also stock soil moisture meters, potting and seed raising mixes, soil wetting granules and Easy Wetta crystals in the shop. They're not all on the website, so give us a ring on (08) 8536 4333 to check what's on the shelf, or come and have a look through the garden centre while you're in.

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I'm still the one who has to physically walk away from the watering can on a Sunday, so if you're not sure what your soil is doing, come and ask me in the shop and we'll work it out together.

Candeece