Everyone wants a healthy pond full of beautiful Koi and lovely plants but do you know which plants are DEADLY to your Koi?
You are always careful to make sure your water is stable and you do not over feed your fish but have you ever thought of the hidden dangers?
Pond owners should exercise caution when situating all plantings as any plant debris that enters the pond, toxic or not, will contribute to the decline of your water quality.
The seeds of most plants can swell and plug up the digestive tract of the Koi. A partial list of the plants or parts of plants that have been reported
as having some toxicity to Koi (and pets and people) for various reasons include:
| Plant Name | Part |
| ACOKANTHERA | fruit and flowers |
| ACONITUM | roots, flowers, and leaves |
| ALLAMANDA | all parts |
| ALLSPICE | leaves, seeds |
| ALOCASIA | leaves and stems |
| ALOE | leaves |
| AMARYLLIS | bulbs contain alkaloids |
| ANENOME | all parts |
| ANGEL TRUMPET TREE (Datura Arborea) | flowers and leaves |
| ANTHURIUM | all parts |
| APPLE | all parts, seeds contain hydrocyanic acid |
| APRICOT | all parts, seeds contain hydrocyanic acid |
| ATROPA BELLADONNA | all parts, especially black berries |
| AUTUMN CROCUS (C. Sativus, Saffron Crocus) | bulbs |
| AZALEAS (Rhododendorn) | all parts can be fatal |
| BANEBERRY (Actaea, Doll's Eyes) | red or white berries, roots and foliage |
| Balsam Pear Seeds | outer rind of fruit (Momordica charantia) |
| BEACH PEA (Lathyrus Maritimus) | stems |
| BETEL NUT PALM | all parts |
| BIRD OF PARADISE BUSH (Caesalpinia) | seeds |
| BITTERSWEET (Celastrus) | berries |
| BLACK LOCUST (Robinia Pseudoacacia) | bark, sprouts, and foliage are poisonous |
| BLACK WALNUT | hulls |
| BLEEDING HEART (Dicentra, Dutchman's Breeches) | foliage and roots |
| BLUEBONNETS (Lupinus) | all parts |
| BOTTLEBRUSH (Callistemon, possibly Melaleuca) | flowers |
| BOXWOOD (Buxus Sempervirens) | all parts |
| BUCKEYE (Aesculus, Horse Chestnut) | sprouts and nuts |
| BUTTERCUP (Ranuculus, Crowfoot) | all parts |
| CALADIUM | all parts |
| CALIFORNIA TERN | roots seeds |
| CALLA LILY (Zantedeschia) | all parts |
| CARDINAL FLOWER | all parts |
| CAROLINA JESSAMINE (Gelsemium) | All parts |
| CASTOR BEAN (Ricinus Communis) | seeds can be fatal |
| CHERRY | pits |
| CHERRY LAUREL (Prunus Varieties) | all parts, seeds contain hydrocyanic acid |
| CHINABERRY (Melia Azedarach) | berries are poisonous |
| CHOKE CHERRY | all parts |
| CHRISTMAS BERRY (Heteromeles Arbutifolia, Toyon) | berries are poisonous |
| COLOCASIA | all parts |
| COLUMBINE (Aquilegia) | all parts |
| COMMON PRIVET (Ligustrum) | black or blue wax coated berries and leaves |
| CORAL BERRY (Symphoricarpos) | seeds |
| COTONEASTER | all parts |
| CROCUS | all bulbs |
| CROTON | seeds |
| DAPHNE | berries can be fatal |
| DAFFODIL (Narcissus) | bulbs may be fatal |
| DATURA (Brugmansia) | flowers, berries, & seeds |
| DEATH-CAMAS (Sygadenus Venous) | all parts poisonous, roots are deadly |
| DEADLY NIGHTSHADE (Solanum Nigrum) | all parts, unripe fruit and foliage |
| DELPHINIUM (Larkspur annual) | all parts |
| DESTROYING ANGEL (Amanita Phalloides, Death Cup) | all parts |
| DIEFFENBACHIA (Dumb Cane) | all parts, especially the sap |
| DIGITALIS | all parts |
| DOGWOOD (Cornus) | fruit slightly poisonous |
| EGGPLANT | all but fruit |
| ELDERBERRY (Sambucus) | red fruit poisonous, black and blue fruit o.k. |
| ELEPHANT EAR (Colocasia, Taro, Caladium) | all parts |
| ENGLISH IVY (Hedera Helix) | berries |
| EUPHORBIA (Splurge, Gopher Plant, Mole Plant) | roots, sap |
| FALSE HELLEBORE (Veratrun Viride and other species) | all parts poisonous, root deadly |
| FOXGLOVE (Digitalis Purpurea) | all parts can be fatal |
| FLY AGARIC (Fly Amanita Mushroom) | whole plant |
| FOUR O'CLOCK | whole plant |
| GELSEMIUM (Carolina Jessamine) | whole plant |
| GLORIOSA LILY | all parts |
| GOLDEN CHAIN | seeds and pods may be fatal |
| HELLEBORE (Ranunculaccea) | all parts |
| HEMLOCK (Tsuga) | all parts, especially roots |
| HENBANE | all parts |
| HOLLY (Ilex Aquifolium, Opaca, Vomitoria) | leaves and berries |
| HONEYSUCKLE | flowers and leaves |
| HORSE CHESTNUT (Aesculus, Buckeye) | all parts |
| HORSETAIL (Equisetum Hyemale) | all parts |
| HYACINTH | bulbs can be fatat |
| HYDRANGEA | whole plant |
| IMPATIENS (Balsam, Touch-Me-Not, Snapweed) | whole plant |
| INDIAN TURNIP | all parts |
| IRIS | underground stemt, leaves, and rhizomes |
| IVY (Hedera) | all parts |
| JACK-IN-THE-PULPIT (Arisaema Triphylla) | root is irritant and astringent |
| JAPANESE LAUREL | all parts |
| JASMINE, YELLOW | all parts |
| JAVA (LIMA) BEAN | uncooked bean |
| JERUSALEM CHERRY (Solanum Pseudocapsicum) | fruit and leaves |
| JESSAMINE (Gelsemium Sempervirens) | berries are fatal |
| JIMSON WEED (Datura Stramomium, Thorn Apple) | all parts |
| LAMBKILL (Kalmia Angustifolia, Sheep Laurel) | leaves |
| LANTANA CAMARA (Red Sage) | all parts, green berries are fatal |
| LARKSPUR (Delphinium) | foliage and roots are dangerous, seeds may be fatal |
| LAUREL (Primus varieties) | all parts can be fatal |
| LILY (Lilium) | some varieties bulbs |
| LILY-OF-THE-VALLEY (Convallaria Majalis) | all parts |
| LOBELIA (Cardinal Flower) | all parts |
| LOCOWEED (Astragalus, Oxytropis) | all parts |
| LOCUST | bark,leaves, seeds |
| LUPINE (Lupinus) | seeds |
| MACHINEEL | all parts |
| MARIJUANA | all parts |
| MAY APPLE (Podophullum) | all parts |
| MESCAL (Peyote) | all parts |
| MILKWEED (Asciepias) | all parts, especially sap |
| MIMOSA | all parts |
| MISTLETOE | all parts, berries can be fatal |
| MOCCASIN FLOWER (Lady Slipper, Cypripedium Spectabiles) | all parts |
| MOCK ORANGE (Philadelphus) | all parts |
| MONKSHOOD (Aconitum) | foliage and fleshy roots |
| MORNING GLORIES (Ipomea) | all parts |
| MOUNTAIN LAUREL (Kalmia Latifolia) | young leaves and shoots, can be fatal |
| MUSHROOMS | wild types |
| MUSTARD | roots and seeds |
| NARCISSUS (Daffodil) | bulbs can be fatal |
| NATAL CHERRY (Solanum) | berries |
| NICOTIANA (Flowering Tobacco) | leaves |
| NIGHTSHADE (European Bittersweet, Horse Nettle) | all, especially unripe berries |
| OAK | foliage and acorns |
| OLEANDER (Nerium Oleander) | All parts poisonous including smoke if burned |
| PEACH see Cherry Laurel, | seeds |
| PEAR see Cherry Laurel, | seeds |
| PEONY (Paeonia) | all parts |
| PERIWINKLE (Vinca, Myrtle) | whole plant |
| PHILODENDREN | leaves and sap |
| PINE | sap |
| PINKS (Sweet William, Carnation, Dianthus) | all parts |
| PLUM see Cherry Laurel, | seeds |
| POKEWEED (Phytolacca, Pokeberry) | roots are dangerous |
| POINSETTIA (Euphorbia Pulcherrima) | all parts, leaves and sap can be fatal |
| POISON IVY (Rhus Radicans) | all parts |
| POISON OAK (Rhus Diversioba, Rhus Toxicondendron) | all parts |
| POPPY (Papaver) | all except California Poppy can be dangerous |
| POTATO | sprouts and foliage can be fatal particularly ornamental varieties |
| PRIVET (Ligustrum) | leaves and fruit |
| PRUNUS (many varieties) | seeds, some parts |
| RANUNCULUS | all parts |
| REDWOOD | sap, (from decks also) |
| RHODODENDRON (Azalea) | all parts can be fatal |
| RHUBARB (Rhenum Rhaponticum) | all parts |
| ROSEMARY (Rosemarius Officinalis) | leaves of certain varieties are poisonous |
| SAGE (Salvia) | leaves of certain varieties are poisonous |
| SCOTCHBROOM (Cytinsus Scoparious) | seeds, invasive |
| SENECIO | whole plant of some species |
| SNAPDRAGON (Antirrhinum) | all parts |
| SNOWDROP (Galanthus) | all parts |
| SOLANUM (Nightshade) | all, especially some berries |
| SQUIRREL CORN (Dicentra Canadensis, Bleeding Heart) | all parts |
| STRAMONIUM (Jimson Weed, Datura) | all parts |
| SUMAC (Rhus) | all parts |
| SWEET PEA (Lathyrus) | stems |
| TANSY (Tanacetum) | all parts |
| TARO (Colocasia, Elephant's Ear) | stem and leaves |
| TIGER LILY (Lilium Tigrinum) | all parts |
| TOADSTOOLS | can be fatal |
| TOBACCO | all parts |
| TOMATO | foliage and vines |
| TRUMPET VINE | all parts |
| TULIP (Tulipa) | bulbs of some varieties |
| VINCA (PERIWINKLE) | all parts |
| YEW | foliage, bark, seeds |
