What are your thoughts on weeding the garden in a heatwave? I’ve come across so many different opinions on it that I’m now really confused. Some gardeners are saying it’s essential to prevent weeds from competing for water and nutrients, and others are arguing that it’s a really bad idea.
Elaine M, Co Cork
By and large, I agree with the latter point of view, which is that it’s a bad idea. As the saying goes, bare soil is bad soil, especially so in the searing heatwaves we’ve experienced recently where plants and the ground were exposed to prolonged periods of high temperatures and zero rainfall.
In these extreme growing conditions, weeds can act as a valuable protective mantle, conserving soil moisture and humidity while shielding the soil from the worst of intense heat and penetrating sun. Despite their natural vigour and resilience, most weeds are also much less likely to grow abundantly during a heatwave (so they’re less of a problem), while removing them can have a negative impact on soil health and the complex interdependent network of microorganisms that combine to sustain healthy growth and fertility.
Of course, that’s not the case in a typical growing season where the average temperatures and rainfall amounts are within seasonal norms for Ireland. In that scenario, the benefits of removing weeds from flower and vegetable beds outweigh any drawbacks, encouraging the healthy growth of garden plants and reducing the risk of plant pests and diseases. But as seasonal extremes continue to break new records, we gardeners will increasingly need to experiment with unconventional ways to help sustain soil and plant health in our gardens and allotments.
I’ve tried to find a middle ground in my own garden this summer by using sharp secateurs to cut back large weeds in flower and vegetable beds such as dock, thistle, nettle and dandelion before they set seed. This helps to prevent them from quickly colonising bare ground once growing conditions return to normal. In the meantime, their leafy canopy acts like the horticultural version of sunscreen, protecting garden plants and the soil from excessive heat as well as slowing evaporation, thus protecting soil moisture levels.
RM Block
In those situations where I’ve had to hoe or hand-weed during the recent heatwave (for example, to make space for new plantings), I’ve left the uprooted weeds on the ground as a protective mulch to rot down. Again, that’s not something I’d do if the weather were wet and cool. But climate change is demanding we adapt to new norms and change how we garden.
