All garden plants need water to thrive; some can survive on rainfall alone, while others require more frequent watering. Many gardeners focus on how often plants need to be watered, but timing is equally, if not more important, for overall plant health. Sneaky pathogens can take hold when plants are left damp for too long, turning lively beds and borders into wilted ones.
Jane Fairlie, technical development manager at Doff Portland, a manufacturer of premium garden care products, notes that watering is an essential gardening job to prioritise this month. Longer days allow for more time to consider when best to water plants, yet many people make the mistake of watering in the middle of the day.
Many of us enjoy a sunny afternoon in the garden, which seems like an opportune time to do some gardening, such as mowing the lawn or weeding.
As for watering, Jane suggests that this is not recommended in the warmer weather, which typically comes from June to September in the UK.
“Water in the early morning or evening to reduce evaporation and help moisture reach the roots,” said Jane.
She urged gardeners to “always direct water at the base of the plant rather than over the leaves”.
Doing so reduces the risk of fungal diseases, which thrive in moist, damp environments. When plant leaves stay damp for hours, like they do if watered at night, it creates a perfect breeding ground for common fungal pathogens such as powdery mildew and leaf spot.
These diseases can spread quickly, damaging foliage, stunting growth, and in some cases, killing plants altogether.
Jane notes that watering alone isn’t enough when it comes to encouraging healthy plants, but you can add an extra step to your gardening routine.
It’s as simple as mulching. Though often recommended in spring, Jane suggests mulching now is a great way to “lock in moisture”.
Mulching around plants is easy; just spread the organic matter around the base of the planting sites.
Jane said: “Organic mulches like bark, compost or well-rotted manure also help suppress weeds while nourishing the soil.”
It is generally best to water plants before mulching. Mulch, while beneficial for moisture retention, can slow down water penetration to the roots, so ensuring the soil is thoroughly moist before mulching is ideal.
How to water plants in summer
According to the Royal Horticultural Society, plants should be watered more thoroughly but less frequently. This ensures deeper penetration of the root tips.
However, when plant roots are restricted, such as in containers or when growing alongside a wall or fence post, more frequent watering may be necessary because the roots are extracting water from a smaller volume of soil than they would if they were growing freely in the border soil.
Establish a garden watering routine before drought really sets in to keep the soil moisture levels high and avoid panic-watering in very dry, scorching spells.
The RHS advises against keeping the soil “really wet all the time” because plants’ roots need air and water to grow well.