Tomato growers should cover soil with one thing to prevent 'devastating' disease (2025)

Tomatoes are easy to grow and relatively low-maintenance, but gardeners should be wary of the leaves as April's warm yet wet weather is perfect for a very destructive disease called blight

Tomatoes are famed for being a breeze to cultivate and require minimal fuss, but growers must keep a vigilant watch on their foliage. April's characteristic mix of warmth and rainfall sets the stage for a highly destructive disease known as blight. Blight is propagated by fungal spores carried in water and once it infiltrates a garden, it's notoriously difficult to rein in due to its rapid spread.

It typically takes hold at the base of plants, leading to leaves becoming speckled, brown and withered, thereby hampering the tomato's energy production. A plant with feeble leaves will struggle to photosynthesise, resulting in stunted growth unlikely to yield any fruit.

Should a tomato plant somehow manage to bear fruit, the produce will rot on the stem and become unfit for eating as the disease takes hold of the whole plant.

How to shield tomatoes from blight in spring

Early blight is a frequent issue around this time, but gardeners needn't fret, as there's a straightforward solution to halt this disease: avoid letting excessive moisture linger around the plant.

Tomatoes require ample space to flourish, as good air circulation aids in drying their leaves swiftly post-rainfall, reports the Express. Ensure each plant has sufficient room and full sun exposure, as tomatoes grown in shaded areas are more prone to remaining damp, which fosters disease.

To ensure your tomato plants thrive, it's crucial to water them at the base, close to the soil. Overhead watering is a no-no as it can leave leaves wet and create the perfect breeding ground for spore growth.

Gardening expert Bob Wildfong from Seeds of Diversity has shared his top tip for fending off blight - keep rain and spores away by mulching your tomatoes well.

He explained: "That splash zone is where infected soil will infect your tomato plants. Fortunately, a good mulch will completely prevent the soil from splashing.

"Whether you use straw, leaf mulch, newspaper, horticultural plastic, or fabric, any good barrier on the ground around your tomato plants will keep the soil from splashing up."

Mulching isn't just about placing a barrier; it's a clever gardening tactic that involves covering the plant base with materials that eventually enrich the soil and feed your plants.

Not only does this method safeguard your tomatoes by stopping the soil from getting too wet and deterring spore growth, but it also maintains soil temperature and moisture, easing plant stress and cutting down humidity near the leaves.

This approach doesn't just combat blight; it helps cultivate robust, healthy plants with a better natural resilience to illness.

Be cautious about mulching your tomatoes too hastily after getting them in the ground – do it prematurely and you could end up with stunted growth and a poor crop yield.

Bob issued a caution, saying: "Just a word of warning about mulching tomatoes, though. While mulch helps prevent blight, helps retain moisture, and keeps weeds down, it also cools the soil.

"If you mulch tomatoes in spring, at the same time you plant them, the cool soil will slow their growth and make them ripen late."

It's best to give your tomato youngsters at least a month's grace to let the earth heat up before blanketing them with straw, shredded paper or any other parched material once they're stable on their feet.

Timed right, a spring mulch means your tomato plants will be poised to thrive – setting the stage for a summer bounty of lush, ripe tomatoes.