Watering is the summer job that matters most, and the one most often done badly. The instinct in hot weather is to water a little every day, sprinkling the surface so it looks wet, but that keeps roots near the surface where they dry out fastest and teaches plants to depend on daily watering. The plants that cope best with summer heat are the ones watered deeply and rarely, with the water going to the roots, in the morning, under a mulch that keeps it there. This guide explains how to water vegetables, fruit, flowers, lawns and containers in summer, how to tell when plants actually need water, and how to use less of it without losing the garden. Check your local extension service for any watering restrictions in your area.
Deep and rare beats shallow and often
The core principle of summer watering is simple: water deeply, so the moisture reaches well below the surface, and then wait until the soil has dried out somewhat before watering again. Deep watering encourages roots to grow down into cooler, moister soil, where they can find water even on hot days. Shallow daily watering does the opposite — it keeps the surface wet, encourages roots to stay at the surface, and leaves the plant helpless the first time you miss a day. As a rough guide, a thorough watering should wet the soil to the depth of a spade, and you can check this by pushing a finger or a trowel into the soil an hour after watering.
How often to water depends on the soil, the weather and the plant. Sandy soil dries fast and may need watering every few days; clay soil holds water for longer and may need watering only once a week, but it needs watering slowly so the water soaks in rather than running off. Young plants, seedlings and transplants need more frequent watering than established plants, and containers need watering far more often than beds. The watering calculator can help you estimate how much water a bed or container needs, and the watering schedule generator can turn that into a routine.
When to water: morning is best
Water in the early morning whenever you can. The soil is cool, evaporation is low, and the water has time to soak down to the roots before the heat of the day. Plants watered in the morning are hydrated before the hottest part of the day, and their foliage dries quickly in the sun, which reduces disease. Watering in the evening is the second-best option, but it leaves foliage damp overnight, which encourages fungal disease, and in a humid summer that matters. Watering in the middle of the day is the least efficient — much of the water evaporates before it reaches the roots — though a plant that is wilting badly should be watered whenever you notice it, whatever the time.
The often-repeated warning that water drops on leaves scorch them in the sun is largely a myth for most plants, but wetting foliage is still wasteful and unhelpful: the water that matters is the water in the soil at the roots. Use a watering can at the base, a soaker hose, or drip irrigation, and keep sprinklers for lawns, where the whole surface needs wetting. If you use a sprinkler on beds, run it in the early morning and long enough to wet the soil deeply, rather than in short bursts that only wet the surface.
Watering vegetables and fruit
Vegetables need consistent moisture in summer, and the crops that suffer most from irregular watering are the ones that show it in the fruit: tomatoes split or develop blossom end rot when watering is erratic, cucumbers turn bitter when they dry out, and lettuce bolts when it is stressed by drought. Keep the soil around fruiting vegetables evenly moist, not wet and not dry, and mulch heavily to even out the moisture. Water at the base of the plant, not over the leaves, and water tomatoes and cucumbers deeply two or three times a week rather than lightly every day. For crop detail, see growing tomatoes and growing cucumbers, and our summer vegetable care guide.
Fruit trees and bushes need deep watering in summer, especially young trees in their first few years and any tree carrying a heavy crop. Water slowly at the root zone, using a soaker hose or a slow-running hose left in place, so the water soaks down rather than running off. A basin of soil or a mulch ring around the tree helps hold the water where it is needed. Established trees with deep roots need less frequent watering than young ones, but a long dry spell will still affect them, and a tree that drops its fruit early is often a tree that is short of water. Our summer fruit care guide covers fruit watering in detail.
Lawns, flowers and containers
Lawns need deep, infrequent watering in summer — a thorough soaking once a week is far better than a light sprinkle every day, and a lawn that is allowed to dry out between waterings grows deeper roots. A lawn that goes brown in a drought is usually not dead but dormant, and it will green up again when rain returns, so think carefully before watering a lawn heavily in a water shortage. Mow high in summer, because longer grass shades the soil and loses less water. Our summer lawn care guide covers the lawn routine in full.
Flowers in beds need watering at the base, especially newly planted ones, while established perennials with deep roots often need little extra water. Containers are the exception to every rule: a pot in full sun can dry out completely in a day, and hanging baskets faster still, so check containers daily and water until it runs from the drainage holes. Group pots together so they shade each other, mulch the surface of the compost, and consider a self-watering pot or a drip system for containers you cannot check every day. Our summer flower care guide covers flowers, and summer houseplant care covers plants moved outdoors.
Saving water in summer
Mulch is the single most effective way to save water in summer: a layer of compost, straw or wood chips over bare soil can cut evaporation sharply, keeping the ground moist for days longer than bare soil. Water with a can or a soaker hose rather than a sprinkler, so the water goes where it is needed and not onto paths and fences. Collect rainwater in butts where you can, and use grey water — water from washing vegetables, or cooled water from cooking — on ornamental plants, but not on anything you will eat raw. The mulch calculator can help you work out how much mulch a bed needs.
Choose your watering priorities in a dry summer: newly planted trees, shrubs and vegetables, and containers come first, because they have the least reserves; established trees, shrubs and lawns come last, because they can usually survive a dry spell. A garden that is mulched, watered deeply and watered at the roots will use far less water than a garden watered lightly every day, and it will look better too. Check your local extension service and your water supplier for any watering restrictions in your area, and follow them — a garden can recover from a dry summer, but a fine for breaking a hosepipe ban is harder to recover from.
How to tell when plants need water
The finger test is more reliable than any schedule: push a finger into the soil to the second knuckle, and if it feels dry at that depth, water; if it feels damp, wait. Wilting in the middle of a hot afternoon does not always mean a plant needs water — many plants wilt in the heat to reduce water loss and recover in the evening — but a plant that is still wilted in the evening does need water. Leaves that are crisp, brown at the edges, or dropping are signs of drought, while yellow leaves and a sour smell from the soil are signs of overwatering, which is just as damaging.
Keep a simple record of when you water and how the garden responds, especially in your first summer in a new garden, because every garden dries out differently. A bed against a south-facing wall dries faster than a bed in light shade, a raised bed dries faster than a bed at ground level, and a windy garden dries faster than a sheltered one. Learning your garden's pattern is worth more than any general rule, and it is the knowledge that makes summer watering easy rather than anxious. For the wider summer routine, browse the guides hub and the planting calendar.
Frequently asked questions
How often should I water in summer?
Water deeply and rarely rather than lightly every day — a thorough watering that wets the soil to spade depth, then wait until the top few centimetres have dried before watering again. Sandy soil and containers need watering more often than clay soil and established beds. Check with your finger, not the calendar.
What is the best time to water in summer?
Early morning is best: evaporation is low, water soaks down to the roots, and foliage dries quickly. Evening is second best but leaves foliage damp overnight. Water a wilting plant whenever you notice it, whatever the time of day.
Why are my tomatoes splitting?
Tomatoes split when watering is irregular — a dry spell followed by a heavy watering swells the fruit faster than the skin can stretch. Keep the soil evenly moist with deep, regular watering and a thick mulch, and water at the base rather than over the plant.
How can I save water in summer?
Mulch bare soil, water at the roots with a can or soaker hose instead of a sprinkler, collect rainwater, and prioritise newly planted and container plants. A mulched garden watered deeply uses far less water than one watered lightly every day.
Do lawns need watering in summer?
A lawn watered deeply once a week is better than one sprinkled daily, and a lawn that goes brown in drought is usually dormant rather than dead — it will green up when rain returns. Mow high in summer, and check your local extension service for lawn advice in your area.