Diagnose a plant problem

Agapanthus, Aglaonema, Alocasia, Aloe vera, Amelanchier, Anthurium, Apple, Apricot, Asparagus, Aubergine, Basil, Bay, Bearded iris, Beetroot, Berberis, Bird of paradise, Blackberry, Blackcurrant, Blue fescue, Blueberry, Borage, Boston fern, Broad bean, Broccoli, Brunnera, Brussels sprouts, Buddleja, Cabbage, Calathea, Californian lilac, Camellia, Carrot, Cauliflower, Celeriac, Celery, Chamomile, Chard, Cherry, Chervil, Chicory, Chilli pepper, Chinese money plant, Chives, Christmas cactus, Clematis, Climbing hydrangea, Coriander, Courgette, Crab apple, Crocosmia, Crocus, Cucumber, Curry leaf, Daffodil, Dahlia, Deutzia, Dieffenbachia, Dill, Dragon tree, Echeveria, Echinacea, Endive, Epimedium, Escallonia, Evergreen climbing hydrangea, Fatsia, Feather reed grass, Fennel, Fig, Firethorn, Fittonia, Forsythia, Foxglove, French bean, Fuchsia, Garlic, Garlic chives, Gladiolus, Globe artichoke, Golden-scaled male fern, Gooseberry, Grape, Grape hyacinth, Hard shield fern, Hardy cyclamen, Hardy geranium, Hart's tongue fern, Haworthia, Hawthorn, Heartleaf philodendron, Hebe, Hellebore, Heuchera, Hippeastrum, Holly, Honeysuckle, Hosta, Hoya, Hyacinth, Hydrangea, Hyssop, Jade plant, Japanese forest grass, Japanese maple, Jerusalem artichoke, Kale, Kentia palm, Kohlrabi, Lady fern, Lamb's lettuce, Land cress, Lavender, Leek, Lemon balm, Lemon thyme, Lemon verbena, Lemongrass, Lettuce, Lily, Loganberry, Lovage, Magnolia, Mahonia, Maidenhair spleenwort, Male fern, Marjoram, Melon, Mexican feather grass, Mexican orange blossom, Mint, Miscanthus, Mock orange, Monstera, Moth orchid, Nerine, Onion, Oregano, Ornamental allium, Ostrich fern, Pak choi, Parlour palm, Parsley, Parsnip, Passionflower, Pea, Peace lily, Peach, Pear, Peony, Peperomia, Pieris, Plum, Potato, Pothos, Pumpkin, Quince, Radish, Raspberry, Redcurrant, Rhododendron, Rhubarb, Rocket, Rose, Rosemary, Rowan, Royal fern, Rubber plant, Rudbeckia, Runner bean, Sage, Salad burnet, Salvia, Savory, Sedge, Shallot, Shiso, Silver birch, Skimmia, Snake plant, Snowdrop, Soft shield fern, Sorrel, Spider plant, Spinach, Spring onion, Star jasmine, Strawberry, String of hearts, String of pearls, Swede, Sweet pepper, Sweetcorn, Swiss cheese vine, Syngonium, Tarragon, Tayberry, Thai basil, Thyme, Tomato, Tuberous begonia, Tulip, Turnip, Viburnum, Vietnamese coriander, Weigela, Whitecurrant, Winter savory, Winter squash, Wisteria, Yew, ZZ plant.