UK Garden Planner
Most garden problems are diagnosable from the symptoms on the plant — the pattern of damage, the colour change, the location on the plant, and whether it's spreading. The identifier above works by narrowing down possibilities from your plant type and the symptoms you can see, then explaining what is causing the problem and how to treat it. Here are the most common issues UK gardeners face:
Overwatering is the most common cause — roots deprived of oxygen can't take up nutrients. Also caused by nitrogen deficiency (pale yellow starting on older leaves), iron deficiency (yellowing between veins on young leaves), or natural ageing on lower leaves.
Irregular holes with slime trails indicate slugs or snails — most active after rain and at night. Small round holes on brassicas are flea beetle. Ragged holes on leaves with caterpillars present are usually cabbage white caterpillars or vine moth larvae.
Powdery mildew — a fungal disease that thrives in warm, dry conditions with poor air circulation. Common on courgettes, cucumbers, roses and gooseberries. Treat with a bicarbonate of soda spray or remove and dispose of affected leaves.
Wilting in dry soil means underwatering. Wilting in moist soil usually indicates root rot from overwatering, vine weevil larvae eating roots, or a fungal wilt disease. Check the roots — healthy roots are white or cream, rotted roots are brown and mushy.
Blossom end rot is calcium deficiency caused by irregular watering — not enough water prevents calcium uptake. Blight appears as brown patches spreading from leaf tips with a damp smell. Remove blighted material immediately and don't compost it.
Sticky honeydew on leaves with distorted new growth usually indicates aphids — check the undersides of leaves and growing tips. Encourage natural predators like ladybirds and lacewings, or use an organic insecticidal soap spray.
The most effective organic pest control combines physical barriers, encouraging beneficial insects, and targeted treatments only when needed. Copper tape deters slugs. Fine mesh netting prevents carrot fly, cabbage white butterflies and vine weevil. Companion planting with marigolds, nasturtiums and herbs confuses and deters many common pests — see the companion planting checker for specific plant combinations.
Use the identifier above to diagnose your specific problem, then follow the treatment advice for organic and conventional solutions. See all free GrowGuide tools →