Potentially harmful garden plants

Serious poisoning by plants is very uncommon in the UK. Some garden plants present a hazard, but the risk of severe poisoning, skin reaction or allergy is generally low.

Aconitum carmichaelii Arendsii Group. Credit: RHS/Graham Titchmarsh.
Aconitum carmichaelii Arendsii Group. Credit: RHS/Graham Titchmarsh.

Quick facts

If it is not a food plant, do not eat it.
Teach children not to play with or eat growing plants.
Use gloves when pruning or weeding and keep skin covered.
Do not leave prunings or uprooted plants in reach of farm animals or pets.
Check plant labels for toxicity warnings (sometimes stated on label).

What are the hazards?

Ingestion hazard

  • Children are mostly at risk
  • Some plants may cause digestive upset or discomfort if eaten
  • A small of number common garden plants are more toxic and could cause severe poisoning (see plant list below)

Contact hazard

  • Irritant sap may cause a burning sensation and sometimes blistering of the skin; anyone can be affected if exposure is sufficient
  • Some plants contain chemicals called allergens. These do not affect everyone, but some individuals may acquire sensitivity to them, resulting in an allergic reaction
  • A very small number of plants have sap which renders the skin excessively sensitive to strong sunlight. Contact with the plant followed by exposure to sunlight results in very severe, localised sunburn with blistering and long-lasting skin discoloration

What to do if there's a problem...

Human ingestion or skin contact

  • If you think a child or adult has eaten part of a doubtful plant, seek medical advice immediately from a hospital Accident & Emergency department
  • Take a sample of the plant with you
  • Do not panic and DO NOT try to make the person sick


The HTA Guide to Potentially Harmful Plants gives toxicity information for pets, including dogs, cats, rabbits, rodents, tortoises, caged birds, poultry. Where a particular pet is mentioned in the HTA Guide this indicates that type of pet has been adversely affected by a plant; it does not mean that other types of pet will not be affected if they eat or rub against the plant.
  • Seek veterinary advice if you think an animal has eaten a poisonous plant
  • Take along samples of the plant concerned

Plant and Fungi Poisons Information

RHS Gardening Advice

For information about particular risks presented by potentially harmful plants contact RHS Gardening Advice; Tel: (01483) 479700, 10am to 4pm, Monday to Friday.


Fungi are safe to have in the garden as long as they are not eaten. With a couple of exceptions, the effects of accidently eating small amounts are mild.  If you need to identify a mushroom, take photos from all angles, from the top, sides and from underneath so the stem (stipe) and gills/pores are visible.  It is safe to touch fungi, as long as you wash your hands afterwards.

In cases of suspected poisoning, seek medical assistance at an Accident and Emergency Department, taking a sample of the plant or fungus/mushroom with you. 

For identification of fungi in non-emergency situations, members of the RHS can send good photos via MyRHS

Plants potentially harmful to people

This list of plants mirrors the HTA (Horticultural Trades Association) guidelines and includes garden plants and houseplants that have been known to cause injury, either by contact or after being eaten.

All these plants are safe to grow provided they are treated with respect. Remember, they are ornamental plants, often very beautiful - they are not meant to be eaten. Avoid contamination by wearing gloves and covering your skin.

This is not an exhaustive list. Additional information on toxicity and irritation can be found on plants listed in our Find a Plant tool so if a specific plant you wish to check isn't listed below, do try searching there as well.
Plants are listed in categories, A being the most toxic.

Category A

Toxicodendron (poison ivy): CAUTION Skin allergen causing severe dermatitis; Poisonous if eaten

Category B

Aconitum (monkshood) - toxic if eaten. Avoid skin contact
Allium sativum - skin irritant/allergen
Alocasia (taro) -  toxic if eaten; skin/eye irritant
Anticlea (Zigadanus some species) - toxic if eaten
Aristolochia (Dutchman's pipe) - toxic if eaten
Arum (cuckoo-pint, lords-and-ladies) - toxic if eaten; skin & eye irritant
Asarum - toxic if eaten
Atropa (deadly nightshade) - toxic if eaten; skin irritant
Brugmansia (angel’s trumpet) - toxic if eaten; skin irritant; avoid eye contact
Brunfelsia (yesterday, today and tomorrow) - harmful if eaten
Colchicum (autumn crocus) - toxic if eaten
Convallaria majalis (lily-of-the-valley) - toxic if eaten
Cuckoo-pint - see Arum
Curcubita - ornamental varieties - toxic if eaten; fruit intended for decoration only
Cycas - harmful if eaten; skin irritant
Daphne (mezereon, spurge laurel) - toxic if eaten; skin irritant
Datura (thornapple) - toxic if eaten; skin irritant; avoid eye contact
Deadly nightshade - see Atropa
Dictamnus (burning bush) - toxic to skin with sunlight
Dieffenbachia (dumb cane, leopard lily) - toxic if eaten; skin/eye irritant
Dioscorea (syn. Tamus) - toxic if eated;  skin irritant
Digitalis (foxglove) - toxic if eaten
Dumb cane - see Dieffenbachia
Euphorbia (spurge, poinsettia) - Irritant to skin/eye; harmful if eaten
Foxglove - see Digitalis
German primula - see Primula obconica
Ginkgo biloba - seeds harmful if eaten
Gloriosa superba (glory lily) - toxic if eaten
Hemlock water-dropwort - see Oenanthe
Heracleum mantegazzianum (giant hogweed) - toxic to skin with sunlight
Heracleum sphondylium (hogweed, common hogweed) and other Heracleum spp - toxic to skin with sunlight
Hogweed - see Heracleum
Humulus lupulus - skin irritant/allergen
Hyoscyamus (henbane) - toxic if eaten
Lagenaria (bottle gourd, calabash) - toxic if eaten; fruit intended for decoration only
Lily-of-the-valley -  see Convallaria majalis
Lords-and-ladies - see Arum
Lupinus (lupin) -harmful if eaten
Mezereon - see Daphne
Monkshood  - see Aconitum
Nerium oleander (oleander) - toxic if eaten; smoke from burning is harmful
Oenanthe crocata, O. aquatica, O. phellandrium (hemlock water-dropwort, water dropwort) - toxic if eaten
Ornithogalum (chincherinchee, star-of-Bethlehem) -  harmful if eaten
Poinsettia - see Euphorbia
Phytolacca (pokeweed) - toxic if eaten
Pokeweed - see Phytolacca
Polygonatum (Solomon’s seal) - harmful if eaten
Primula obconica (except primin-free cultivars) (German primula), and P. auricula - skin irritant
Ricinus communis (castor oil plant) - toxic if eaten
Ruta (rue) - toxic to skin with sunlight
Solomon’s seal - See Polygonatum
Spurge laurel - see Daphne
Star-of-Bethlehem - see Ornithogalum
Tamus - see Dioscorea

Taxus (yew) - toxic if eaten
Thornapple - see Datura
Veratrum (false hellebore)  - toxic if eaten
Water-dropwort - see Oenanthe
Yesterday, today and tomorrow - see Brunfelsia
Yew - See Taxus

 Category C

Acokanthera (bushman’s poison) - harmful if eaten
Actaea (baneberry) - harmful if eaten
Adenium - harmful if eaten
Aesculus (horse chestnut) - harmful if eaten
Agapanthus (African lily) - harmful if eaten
Agave - skin irritant
Aglaonema (Chinese evergreen) - harmful if eaten; skin/eye irritant
Agrostemma githago (corncockle) - harmful if eaten
Ailanthus (tree of heaven) - skin irritant
Allamanda -harmful if eaten; skin/eye irritant
Aloe - harmful if eaten
Alstroemeria (Peruvian lily) - skin allergen
Amaryllis - see Hippeastrum
Angel’s trumpet - see Brugmansia
Angel’s wings - see Caladium
Anthriscus sylvestris (cow parsley) - harmful to skin with sunlight
Anthurium (flamingo flower) - harmful if eaten; skin/eye irritant
Apium graveolens (celery/celeriac) - harmful to skin with sunlight
Arachis hypogaea - (Seed packets only) seeds from this packet are not edible
Arisaema (cobra-lily) - harmful if eaten; skin/eye irritant
Arisarum (mouse plant) - harmful if eaten; skin/eye irritant
Arrowhead vine - see Syngonium
Asclepias -
harmful if eaten
Asparagus (asparagus fern) - skin allergen; fruits harmful if eaten
Autumn crocus See Colchicum
Azalea - see Rhododendron
Baneberry - see Actaea
Belladonna lily - see Amaryllis belladona
Bluebell - see Hyacinthoides
Brassica nigra, B. juncea (black mustard, brown mustard) - skin irritant/allergen
Bryonia dioica (white byrony) - harmful if eaten
Buckthorn - see Rhamnus
Bunny ears cactus - see Opuntia
Burning bush - see Dictamnus
Bushman’s poison - see Acokanthera
Caladium (angel’s wings) - harmful if eaten; skin/eye irritant
Calico bush - see Kalmia
Calla lily - see Zantedeschia
Calla palustris (water arum) - harmful if eaten; skin/eye irritant
Calycanthus - Carolina allspice - harmful if eaten
Capsicum annum (ornamental pepper cultivars)- irritant if eaten; skin/eye irritant
Castor oil plant - see Ricinus communis
Celandine, greater - see Chelidonium majus
Chelidonium majus (greater celandine) - harmful if eaten; skin/eye irritant
Cherry laurel - see Prunus laurocerasus
Chincherinchee - see Ornithogalum
Christmas cherry - see Solanum pseudocapsicum
Chrysanthemum - skin allergen
Citrus (lemon, lime, bergamot orange) - fruit harmful to skin in sunlight
Clematis (old man's beard) - skin irritant
Cobra-lily - see Arisaema
Colocasia esculenta (dasheen, eddo, taro) - harmful if eaten; skin/eye irritant
Comfrey, Russian comfrey - see Symphytum
Corncockle - see Agrostemma githago
Curcubita - edible varieties (courgette, pumpkin, squash) - if crop is bitter, do not eat
Cymbidium - skin allergen
Cypripedium (lady's slipper orchid) - skin allergen
Cytissus - (broom) - harmful if eaten
Daffodil - see Narcissus
Dasheen - see Colocasia esculenta
Delphinium including Consolida (larkspur) - harmful if eaten
Devil’s ivy - see Epipremnum
Dianthus (carnation, sweet William) - skin allergen
Dracunculus (dragon arum) - harmful if eaten; skin & eye irritant
Echium - skin irritant
Elder - see Sambucus
Epipremnum (devil’s ivy) - harmful if eaten; skin & eye irritant
Euonymus (spindle tree) - somewhat poisonous
Ficus benjamina (weeping fig) - may cause skin allergen, harmful if eaten
Ficus carica (fig) - harmful to skin with sunlight
Fig - see Ficus
 (alder buckthorn) - harmful if eaten
Fremontodendron - skin/eye irritant
Galanthus (snowdrop) - harmful if eaten
Gelsemium (false jasmine) - harmful if eaten
Goosefoot vine - see Syngonium
Grevillea - skin irritant/allergen
Hedera (ivy) - harmful if eaten; skin irritant/allergen
Helleborus (Christmas rose, Lenten rose) - harmful if eaten; skin irritant
Hippeastrum (amaryllis) - harmful if eaten
Horse chestnut - see Aesculus
Hyacinthoides (bluebell) - harmful if eaten
Hyacinthus (hyacinth) - skin irritant
Hydrangea - skin allergen
Ipomoea (morning glory) - harmful if eaten
Iris - harmful if eaten
Ivy - see Hedera
Juniperus communis (juniper) - skin allergen
Juniperus except J. communis - harmful if eaten, skin allergen
Kalmia (calico bush) - harmful if eaten
Lenten rose - see Helleborus
Laburnum - harmful if eaten
Lagenaria (bottle gourd) (syn. Cucurbita lagenaria), edible varieties - if crop is bitter, don't eat
Lantana - harmful if eaten
Larkspur - see Delphinium
Lathyrus (except L. sativus) - pods and seeds not edible
Laurel - see Prunus laurocerasus
Leyland cypress - see × Cupressocyparis leylandii
Ligustrum (privet) - harmful if eaten
Lithotoma axillaris (syn. Isotoma axillaris, Laurentia axiallaris) - skin irritant
Lobelia (except bedding lobelia, L. erinus) - harmful if eaten, skin irritant
Lysichiton (skunk cabbage) - harmful if eaten, skin & eye irritant
Marvel of Peru - see Mirabilis
Mentha pulegium (pennyroyal) - harmful if eaten
Mirabilis (marvel of Peru, four o’clock plant) - poisonous; skin irritant
Monstera deliciosa (Swiss cheese plant) - harmful if eaten, skin & eye irritant
Morning glory - see Ipomoea
Nandina domestica (sacred bamboo) - harmful if eaten
Narcissus (daffodil) - harmful if eaten; skin irritant
Nicotiana (tobacco) - harmful if eaten; avoid skin contact
Opium poppy - see Papaver somniferum
Opuntia (prickly pear, bunny ears) - skin and eye irritant
Pagoda tree - see Sophora
Papaver somniferum (opium poppy) - harmful if eaten
Parsnip - see Pastinaca sativa
Parthenocissus (Virginia creeper, Boston ivy) - harmful if eaten; skin irritant
Pastinaca sativa (parsnip) - harmful if eaten; skin irritant
Peace lily - see Spathiphyllum
Pepper, ornamental - see Capsicum annum
Peruvian lily - see Alstroemeria
Phacelia - skin allergen
Phaseolus (navy beans, kidney beans, French bean, climbing bean, runner bean) - raw pods/beans harmful if eaten raw
Philodendron - harmful if eaten; skin/eye irritant/allergen
Physalis alkekengi (Chinese lantern) - harmful if eaten, except ripe fruit
Pieris - harmful if eaten
Pistia stratiotes (water lettuce) - harmful if eaten; skin/eye irritant
Plumaria (frangipani) - harmful if eaten; skin/eye irritant
Plumbago (leadwort) - skin irritant
Privet - see Ligustrum
Polyscias - skin irritant
Portugal laurel - see Prunus lusitanica
Primula auricula - skin allergen
Prunus laurocerasus, P. lustanica (cherry laurel, Portugal laurel) varieties bearing ornamental fruit - harmful if eaten
Ranunculus (buttercup, crowfoot, celandine, spearfoot, beakwort) - harmful if eaten; skin irritant
Rhamnus including Frangula (alder buckthorn, buckthorn) – harmful if eaten
Rheum × hybridum  (rhubarb) - harmful if eaten, except cooked leaf stalks
Rheum except R. x hybridum (Chinese rhubarb) - harmful if eaten
Rhododendron, including Ledum, Azalea, Menziesia - harmful if eaten
Robinia pseudoacacia (locust tree) - harmful if eaten; skin irritant
Rumex (dock/sorrel) - harmful if eaten in large amounts
Salvia rosmarinus (rosemary) - skin allergen
Sambucus except S. nigra (elder) - harmful if eaten; fruit/flowers edible if cooked
Sauromatum (voodoo lily) - harmful if eaten; skin/eye irritant
Schefflera (Umbrella tree) - skin irritant
Scilla - harmful if eaten
Skunk cabbage - see Lysichiton
Sinapis alba (white mustard) - skin irritant/allergen
Snowberry - see Symphoricarpos
Solanum tuberosum (potato) - harmful if eaten, except potato crop
Solanum, ornamental species (including S. pseudocapsicum (syn. S. capsicastrum) and S. dulcamara) - harmful if eaten
Sophora (pagoda tree) - harmful if eaten
Spanish broom - see Spartium junceum
Spartium junceum (Spanish broom) - harmful if eaten
Spathiphyllum (peace lily) - harmful if eaten, skin & eye irritant
Spindle tree - see Euonymus
Swiss cheese plant - See Monstera deliciosa
Symphoricarpos (snowberry) - harmful if eaten
Symphytum (comfrey, Russian comfrey) - harmful if eaten repeatedly
Syngonium (arrowhead vine, goosefoot vine) - harmful if eaten; skin/eye irritant
Tagetes minuta - (African marigold, French marigold) - skin irritant/allergen
Taro – see Alocasia, Colocasia
Teucrium (germander) - harmful if eaten
Thermopsis (false lupin) - harmful if eaten
Thuja (western red cedar) - harmful if eaten; skin allergen
Tobacco - see Nicotiana
Tradescantia - skin allergen
Tropaeolum majus (nasturtium) - skin allergen
Tulip - see Tulipa
Tulipa (tulip) - harmful if eaten; skin allergen
Umbrella tree - see Schefflera
Urtica (nettle) - skin irritant
Viscum album (mistletoe) - harmful if eaten
Winter cherry - see Solanum pseudocapsicum
Woody nightshade - see Solanum
×Cuprocyparis leylandii (Leyland cypress) - skin allergen
Yucca - skin allergen
Zamia - see Zamioculcas
Zamioculcas - harmful if eaten, skin/eye allergen/irritant
Zantedeschia (calla lily) - harmful if eaten; skin & eye irritant

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