Strawberry Mottle

Strawberry mottle is an unassuming viral disease that can cut your strawberry crop by 30%.

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Strawberry mottle is one of several viruses that can affect strawberries. Appearing on its own, the damage tends to be relatively isolated. All too often, however, more than one virus appears at the same time. Collectively, this condition is called virus decline and it can eliminate any chance at enjoying a sweet, juicy strawberry from your garden, no matter how well you care for your plants.


Vectors of strawberry mottle disease

Strawberry mottle is carried by insects, most commonly by strawberry, melon, and cotton aphids. This virus is also spread by vegetative propagation of infected plants. Unlike the strawberry mild yellow edge virus, which is retained in an aphid’s gut for its lifetime, the strawberry mottle virus can only be transmitted for 2 or 3 hours after an aphid or other insect has fed on an infected plant. This makes outbreaks remain relatively localized. [Ten feet away probably looks impossible to a flightless bug that is only 1/8” long.]


Symptoms of strawberry mottle

As insects pierce plant cells to suck out the sugary sap, viruses move from the insect’s saliva to the plant. As viruses tend to do, these pseudo-lifeforms start reprogramming a plant’s cells to produce more viruses, which then clog the works. ​

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Strawberry mottle first appears on young leaves as smaller than normal leaves that may also show yellow distorted areas. Plants may be stunted and they certainly produce less fruit and runners than they might otherwise. As the disease progresses, symptoms become more severe, with older leaves turning red.


Strawberry mottle management

Strawberry mottle is more likely when plants are left in place over the winter, but that doesn’t mean you have to rip out your plants every year. [Note: don’t actually rip plants out of the ground. Instead, cut them off at soil level to leave valuable soil microbes in place.]


As always, to reduce the likelihood of strawberry mottle appearing in your garden, only buy certified disease-free plants and always place new plants in quarantine. As much as possible, try to control aphids around strawberry plants. If a plant becomes infected, remove it.