Find out what is wrong with your plant from a photo

Send Fern a photo of a yellowing leaf, a spotted tomato or a drooping houseplant. It lists the likely causes, tells you what to check to tell them apart and suggests the gentlest fix to try first.

Sample result

A sample diagnosis: yellow leaves on a tomato plant

The request

[Photos attached] The lower leaves on my tomato plants are turning yellow with brown spots. What’s going on?

Likely causes

Cause	What points to it	How to check
Early blight (a fungal disease)	Brown spots with rings like a target, starting on the lowest leaves	Look for concentric rings and yellow halos around the spots
Septoria leaf spot	Many small spots with pale centres	Look for tiny dark dots in the centre of each spot
Nitrogen deficiency	Even yellowing of older leaves without distinct spots	Check whether the plant has been fed this season

Try first

Remove the affected lower leaves and bin them; do not compost them.
Water at the base in the morning, keeping the leaves dry.
Mulch under the plants so soil does not splash up onto the leaves.
Give the plants space for air to move between them.

If it keeps spreading

Your local agricultural extension service can confirm the disease and recommend treatments approved in your area. If you use any product, follow its label exactly.

What Fern does

Looks at a photo and lists the likely causes: watering, light, nutrients, pests or disease.
Tells you what to check to narrow it down, like the soil, the undersides of the leaves or the pattern of the damage.
Suggests the gentlest effective fix first, and when to escalate.
Keeps a seasonal care plan with reminders for watering, feeding and pruning.

What Fern won’t do

A diagnosis from a photo is a best guess. For a valuable tree or a serious outbreak, ask an arborist or your local agricultural extension service.
If you use any pesticide, follow its label exactly; Fern never suggests using one beyond its label.
Cannot tell you whether a plant or a mushroom is safe to eat, and cannot judge poisoning. If a child or pet may have eaten a plant, call poison control or a vet straight away.

How it works

Send a photo
A close-up of the problem and one of the whole plant, in daylight if you can.
Answer a few questions
Watering, light, recent weather, how fast it appeared.
Try the first fix
Fern checks back in a week and adjusts if things have not improved.

Questions

How accurate is a diagnosis from a photo?

Often good enough to choose a first step, but many problems look alike. Fern gives you likely causes ranked, plus what to check to tell them apart.

Does it work for houseplants?

Yes. Houseplants, vegetables, lawns, fruit trees and ornamental gardens.

Will it recommend chemicals?

It starts with cultural fixes (watering, pruning, spacing) and, if a product is warranted, describes the type to ask about and reminds you to follow the label exactly.

Can it tell me if a plant is poisonous to my dog?

It can tell you which common plants are generally listed as toxic to pets, but if your pet may have eaten something, call your vet or an animal poison control line straight away.

A sample diagnosis: yellow leaves on a tomato plant

Likely causes

Try first

If it keeps spreading

What Fern does

What Fern won’t do

How it works

Send a photo

Answer a few questions

Try the first fix

Questions

Put Fern to work