My Strawberry Plants Have a Virus — What Do I Do?

Strawberries are susceptible to a number of plant viruses that progressively weaken plants, reduce yield, and — importantly — are spread to healthy plants by aphids. The most significant are strawberry mild yellow edge virus, strawberry crinkle virus, strawberry mottle virus, and arabis mosaic virus. Individual infections may produce mild or even invisible symptoms; mixed infections (two or more viruses in the same plant) produce more severe stunting, mottling, and reduced cropping. Virus cannot be cured — it is permanent and systemic in the plant. The correct response is replanting with clean stock.

Recognising virus in strawberry plants

Virus symptoms in strawberries vary by virus and whether infections are single or mixed. Strawberry mild yellow edge virus causes yellow edges on leaves, eventually affecting the whole leaf. Strawberry crinkle virus causes leaf crumpling and distortion. Strawberry mottle virus produces yellowing and mottling that can be quite subtle. Mixed infections produce plants that are clearly stunted, pale, distorted, and producing significantly smaller and fewer fruits than expected for the variety and growing conditions. Plants that were performing well and then progressively declined over two to three seasons are typical candidates for virus accumulation.

How virus spreads

Strawberry viruses are spread almost entirely by the strawberry aphid (Chaetosiphon fragaefolii) in needle-feeding events — the aphid picks up the virus from an infected plant and injects it into healthy plants in subsequent feeds. A single aphid can spread virus across the entire bed over a season. This is why aphid control matters not for the direct damage aphids cause (which is minor) but for their role as virus vectors. Controlling aphids consistently on a new clean bed extends the period before virus accumulates.

Replanting strategy

When plants are clearly virus-affected, remove and destroy all plants in the bed — do not compost them. Purchase certified virus-free runners or plants from a reputable supplier (plants with certification are produced under strict aphid-free conditions). Plant the new bed at least 2 metres from the old site to reduce the chance of aphid-carried virus moving across immediately. With good aphid management and regular renewal every four to five years, you will always have productive plants.