From hot summer afternoons and icy winter mornings to the age of plants and their overall conditions, there are dozens of factors that can impact how and when we water. But, is there a best time of day to water your plants? Or is it all just a gardening myth?
Well, yes and no. The most important thing to remember is that other than a select handful of drought-tolerant plants, the vast majority of garden and veg plot plants need water, and any time is better than no time.
However, there is a lot of truth in the overwhelming consensus that morning is the best time to water your plants. The soil temperature, the angle of the sun, and the way daylight triggers action from plants’ roots to their fruits, all play a part in why watering in the morning is best for your plants.
Why morning is the best time to water plants: The science
Watering plants in the morning is, without a doubt, the best time of day to water your garden. At the most fundamental level, that’s because of the impact the sun has on your plants, whether they’re indoors, outdoors, in cool climates, or warm.
Most plants are dormant overnight, just check your courgettes for proof. In high summer, when courgettes are growing at their fastest, each fruit can grow over an inch per day. Check that growth in the evening, and again in the morning; nothing. Now, check it in the morning and the afternoon. Hard evidence that your veg patch is doing all of its hard work throughout the day.
While dormant, plants aren’t taking up water, and they’re not photosynthesizing. Watering in the morning means the soil can evenly saturate, and while the soil is being warmed by the morning sun, it isn’t being baked.
In addition, humidity at ground level is higher in the morning, particularly in spring. That means less evaporation and less waste.
When to water your plants – the pros and cons
The easiest answer is definitely to sit back and say ‘morning is the best time to water plants’, but, in reality, if you’re stuck for time, most plants won’t be harmed by watering in the afternoon or even watering at night. Remember, some water is always between than no water. So, let’s look at the pros and cons of watering, depending on the time of day.
Watering plants in the morning, pros and cons
Watering in the morning is best for your plants and your water usage. It’s less wasteful and promotes more natural conditions in most climates.
Pros:
Cons:
Watering plants in the afternoon, pros and cons
Watering in the afternoon, while not necessarily good for the garden, makes the most sense for most people. It’s warm out, the sun’s beating down, and your plants are looking dry, but, there are definitely some precautions worth taking when watering plants in the afternoon.
Pros:
Cons:
Watering plants in the evening, pros and cons
Watering in the evening has its benefits, but I wouldn’t advise it as a standard routine. By watering plants in the evening, you’re essentially soaking the soil while your garden is asleep. This just leads to water wastage.
However, in spring and autumn, when the weather is more humid, adding a bit more water can help to revive dry summer soil, and thaw winter ice. Doing this in the evening has positives and negatives.
Pros:
Cons
Does watering foliage really scorch your plants?
There are many plants that are very susceptible to sun scorch, a phenomenon caused by water sitting on foliage, and acting like a magnifying glass to intensify the sun’s heat. This will crisp foliage, and cause brown or grey patches on the leaves of some garden plants and vegetables.
However, it’s an exception rather than a rule, and most plants will not suffer from sun scorch as a result of watering their foliage, and many will benefit from it (particularly fluffy-leaved plants). That doesn’t mean it’s ok to water foliage though, as a far more common problem is fungal infection.
Fungal spores take hold best on wet, damaged leaves. Watering foliage increases humidity, and in the afternoon, that is paired with heat, creating the perfect conditions for fungal infections to spread.
The other downside to watering foliage is that you’ll simply wastewater. The only way to ensure you don’t lose waste to evaporation is to water at the roots and avoid using spray settings on your hose.
Should you water different plants at different times?
With all the pros and cons of watering at different times taken into account, it’s still firmly agreed that the morning is the best time to water your plants, but that can change depending on the type of plants you’re watering.
What’s the best time to water hedges, trees, and shrubs?
Hedges, shrubs, and fruit trees really don’t care about when they’re watered, and are perfect examples of the ‘any water is better than no water’ rule.
Once established, most fruit trees in the ground need watering only in times of severe drought. While they’re young though, or in containers (lemons and limes for example) they should be watered regularly, and ideally in the morning to make the most of the water you give them.
What’s the best time to water vegetables?
Vegetables will drink actively and quickly at any time of day, but by watering them in the morning they have a better chance of taking in moisture, and actively processing the nutrients in the soil around them.
Root vegetables, however, are actually best watered in the evening. Watering carrots, beetroot, and radishes in the evening means that the water drains slightly. So, by the time morning comes around, they have to search deeper for their moisture, producing faster, stronger growth, and less fibrous roots.
What’s the best time to water seedlings?
Seedlings, and any young plants in a greenhouse, indoors, or in a cold frame, should be watered in the morning, and the morning only. This is particularly true of tender tropical plants like tomatoes, or peppers, which have a tendency to damp off if the soil is left damp for too long.
Watering seedlings in the afternoon are more likely to lead to sun scorch. Watering seedlings in the evening are more likely to lead to damping off, or rot. Always, always, always, water your seedlings in the morning.
Takeaway
Most gardening questions have pretty straightforward answers, but when it comes to watering, detail is key. The plants you’re growing, the stage of life they’re at, and the condition they’re grown in, all have a big impact on how and when you should water them.
If in doubt though, stick to morning watering, as the negative effects are considerably less than water at any other time of day, and, like all gardening chores, you’ll build a habit of it soon enough!
