Black spot is a common fungal disease that affects roses, but one gardener has shared a simple tip to stop the disease from spreading to your plants – and it’s all to do with mulch
Rose enthusiasts, beware: black spot is the arch-nemesis of your beloved blooms – a dastardly fungal disease that can wreak havoc on roses. Once it takes hold in your garden, battling black spot becomes a formidable challenge. The tell tale signs are hard to miss – unsightly spots up to half an inch across, mainly on the upper side of leaves.
As the infestation worsens, leaves turn yellow and fall off too soon, starting from the lower branches and moving upwards. In time, the whole plant might lose its leaves, and even the stems can get infected.
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While black spot might not finish off your roses in the first couple of years, if left unchecked, it weakens them, leaving them vulnerable to other deadly diseases. Kelly Lynch, exasperated by the relentless attack of black spot on her roses, sought wisdom from fellow gardeners on the David Austen Roses Facebook group.
She posted: “Does anyone have any advice for black spot? I’ve tried removing all the infected leaves and don’t overwater, but no matter what I do, most of my roses end up with it.”
In response, many rose lovers in the group suggested mulching as a saviour, particularly given the UK’s recent spells of both wet and dry weather in July, reports the Express.
Ruth Hall shared her success story: “It seems to have helped that I planted my Intrigue rose (prone to black spot) in a bed that has a surface of mulch on top. No moisture on the surface. That seems to help prevent black spot.”
Julie Graig advised on plant care, stating: “Don’t spray. Mulch can protect and nurture the fungal spores. Remove it, clean the area, and snip any infection.” She continued: “Water gently in the early morning or late evening. Keep the area well ventilated, not overgrown.”
In response, Anna Elizabeth shared her own gardening practice: “I try to mulch around the plant, but keep it away from the bud union and not water too much.”
Mulching is a boon for roses, offering them nutritional support, weed control, and moisture conservation. It’s especially beneficial for roses plagued by black spot as it stops soil spores from splashing onto new growth.
A variety of materials can serve as effective mulch, including top-notch garden compost, composted straw or bark, or aged manure sourced from local farms.
However, a word of caution when using manure: ensure it’s at least two years old to prevent root damage, as fresh manure can be too harsh. The mulch should be applied as far out as the rose’s canopy extends, but kept clear of the stem itself.