Watering wisely – 12 top tips and insider secrets
Master horticulturalist Dan Ori shares watering top tips and insider secrets on ‘watering wisely’ from the horticulture industry. You can also watch a video of Dan giving some of his expert tips here.
This content was presented as part of a workshop at the Peverells Community Garden in June 2024.
Check water temperature
Just like us, plants can get a shock from hot or cold water – particularly young plants and seedlings. Check the temperature of your water before using it. In winter, water buts can get very cold. In summer, stored water, and water in hosepipes can heat up. If water is too hot or cold, leave it out in a couple of watering cans for a couple of hours before using it.
Does watering in hot weather scorch leaves?
There’s an old gardening myth about watering in sunlight scorching leaves but it’s not true and has been debunked. In community gardens, you might just have to water when you can – and that’s fine (but see Dan’s evening versus morning watering tip).
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Evening versus morning watering
In hot weather, try to water in the morning or the evening to reduce the amount of water lost through evaporation. There are pros and cons of evening versus morning watering. Evening watering in hot weather means the plants are moist and happy overnight. But in cold weather, it’s better to water early to mid morning – if plants sit in wet soil overnight it can rot their roots.
How to use a watering can
Watering cans come with a rose, but this is only really useful for seeds and seedlings. Use your watering can without the rose, pour gently and slowly around each plant – not on top of it.
How to water seedlings in trays
In the industry, workers are taught to water across and over trays of plants and seedlings – ie water beyond the edge of the tray. This is because if you try to keep all the water within the tray, you’ll end up leaving the plants on the edges of the trays too dry.
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Water woody plants well (w)once weekly
The Five W’s! Woody plants are shrubs and trees. These plants need a really good soak once or twice a week. The water needs to penetrate deep into the soil. It’s a common mistake to water trees and shrubs a little bit, more often, so remember the 5 W’s.
How to tell if a plant needs watering #1
Look at the plant: signs of wilting means the plant needs watering. If the plant is left without enough water for longer, it will sometimes ‘close down’ – for example, a tree will behave as if it’s autumn and drop its leaves. The plant also becomes more susceptible to pests and diseases.
How to tell if a plant needs watering #2
An industry trick to tell if plants in pots need watering is to test their weight. Practice picking up (or tipping, for larger pots) to get a sense of the weight of your pots before and after watering. You’ll quickly get a good sense of whether extra water is needed.
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How to tell if a plant needs watering #3
Use a water meter. The cheapest water meter is your finger! Surface soil might look wet, but a centimetre or so below it can be dry. Poke a finger into the soil and feel what it’s like a few centimetres below the surface. You can also buy water meters quite cheaply – they can be useful tools and engaging for volunteers – especially children. But they are also very easy to lose!
Mulch, mulch, mulch!
Mulch is just a term for a layer of something on the surface of the soil or compost. It makes a huge difference in reducing the water needs of all plants and we hope to do a longer section or workshop on this. A mulch can be anything from gravel, compost, horse manure or woodchip.
Water-hating soil or compost
If soil or compost becomes very dry, it becomes ‘hydrophobic’, which means ‘water-hating’ – ie it won’t absorb water. Water will just pour off the top of soil, or through and out of the bottom of pots. The trick is to add water slowly, let it absorb little by little. Smaller pots can be dunked in a bucket of water.
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Do you need to add drainage to pots?
Adding drainage (a layer of old crocks or stones) to the bottom of pots has been a contentious issue amongst gardeners for years. The current thinking is that it doesn’t help, and can actually cause problems. Just put one piece of crock over the drainage holes to stop them getting blocked.
Watch Dan give some of his expert tips via the Original Gardening YouTube channel