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The best way to water your plants in the summer

Keep your outdoor plants healthy in the heatwave with our best-practice guide to watering
Watering plants at the base

During a heatwave, it's essential to stay hydrated - and the same goes for your plants. 

Soaring temperatures can mean a great tan and more time in the garden for you, but they can spell disaster for plants that aren't properly maintained. It's vital to make sure you're not over or under watering during the summer.

We've summarised some of our top tips to keep your plants hydrated and happy in the heat. These findings are from Which? Gardening magazine's expert research - you can join Which? Gardening to keep up to date on the best ways to look after your garden.

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The best way to water plants

You may think as long as your plants get water, they should be fine. But subtly changing the way you water can stop unnecessary wastage, improve the ease of watering, and help boost the health of your plant.

Watering the base of a plant with a rose-tipped watering can

Our experts found that watering the base of your plant with a rose-tipped watering can is one of the easiest and best ways to ensure great hydration. Watering closer to the soil maximises the spread of water - we found little difference in soil moisture between the soil closest to the plant and soil up to 10cm away.

You may have seen 'hacks' online encouraging you to water your plants using a bottomless plastic bottle - but our experts found this to be the least effective method, even causing drought-stress and reducing the spread of water throughout the area.

To reduce water lost to evaporation on sunny days, you'll want to water in the morning or evening when it's coolest.

Make watering a quick and easy gardening job with one of the best watering cans.

Which veg you should and shouldn't water

Different vegetables have different watering needs and it makes sense to target your water where it is needed most.

We've grouped common veg into three groups depending on their water needs - those which need watering throughout their growth, those that need watering at key growth stages, and those which are pretty much fine left alone.

Water throughout growth

These fast and continuously growing vegetables need approximately 20 litres/m² per week in dry spells:

  • Lettuce, salad leaves, spinach
  • Oriental greens
  • Summer cabbage
  • Radish
  • Calabrese and cauliflower
  • Courgette and cucumber
  • Runner beans

Top tip: Soaking when cauliflower and calabrese heads begin to swell will increase their final size.

Water at key growth stages

Time your watering right to increase your crop yield:

  • Peas and broad beans - a good soak (20 litres/m²) when the first flowers appear and again when the young pods begin to swell should increase the crop in dry weather
  • French beans - water when flowering and again when pods start to form
  • Sweetcorn - give a good soak (20 litres/m²) once cobs start to form and the silks appear
  • Pumpkins and squash - give a few good soakings once fruits begin to swell, and target water near the centre of the plant
  • Tomatoes, aubergines and peppers - once flowers start to set fruit, water regularly all summer (ideally 10 litres/m² twice weekly)
  • Potatoes - once they finish flowering, wet the soil not the leaves, and water throughout growth to encourage new potatoes

Top tip: Before leaving on holiday, sink pot-grown tomatoes into the ground and soak well to keep them going

Water sparingly

These are mainly root vegetables, perennials and over-wintering crops which don't need much attention once established:

  • Beetroot, carrot, parsnips and turnips
  • Onions, garlic and shallots
  • Asparagus and artichokes 
  • Brussels sprouts, sprouting broccoli, spring and winter cabbages

Top tip: When planting seeds into dry soil, water the bottom of the seed drill thoroughly and leave to soak in water before sowing - then cover with dry soil

Reduce the effort of watering

Watering can be a tedious task if you've got a lot of ground to cover (or even if you don't!). One of the best ways to simplify this job is by using a garden irrigation system.

Water irrigation system

Irrigation systems are handy tools for keeping your plants well-watered regularly, whether you're at home or away on your summer holidays. They consist of a series of hoses and pipes which connect to your water supply, allowing you to water multiple plants at once via a drip system.

You can buy them as a kit, and most come with extra accessories like timers, so you can customise your watering schedule even if you're away.

We've tested several of the most popular water irrigation systems on the market to find the best - head to our guide on the best garden irrigation systems for our expert verdict on the top models.

What to water

Water is a valuable and sometimes pricey resource, so it's important to prioritise the plants and areas which need it more and those which don't.

For instance, a browning lawn may ring alarm bells in your head, but grass is hardy and will most likely perk up at the next rainfall, meaning you probably won't need to water it yourself.

When it comes to anything you've planted in the last year, you'll want to focus watering here as these plants will be more vulnerable while they're rooting. For already-established plants, these need far less attention.

Find a reliable hose to keep your garden looking great all summer with one of our best garden hoses and hose guns.

Top gardening tips for summer

Follow our quick and easy tips to make gardening this summer a breeze:

  • Collect rainwater in water butts to save on your next water bill, and use it to water your plants 
  • Cover any bare soil with improver as mulch to help trap moisture in the soil and improve its quality
  • Grow plants best-suited to your soil - plants that like damp conditions won't grow well in dry, chalky or sandy soil 

Avoid common gardening mistakes with our advice on the 5 things not to do in your garden.