Toxic Plants to Fish - Possiblities
While many plants are listed as toxic to fish, some of these plants have been in our ponds for years without any problems. Water Iris is one that is listed as toxic, but we have had water iris in our ponds without problems. Koi are omnivorous and will eat plants. The key is to provide plants koi will eat and are good for them. Watercress is very nutritional for koi with almost the same minerals and vitamins as spirulina algae, and the koi love it. It grows fast enough to keep up with the appetite of the koi if planted properly. Watercress should be planted shallow where there is plenty of water flow. Place rock boulders around the plant to protects the roots, otherwise the koi will uproot the plant. The plant will grow over the rocks and give the koi a good food source. We highly recommend watercress be included in any koi pond that has plants.
| Allamanda – all parts |
| Aloe - leaves |
| Alocasia - leaves and stems |
| Allspice- leaves, seeds |
| Amaryllis - bulbs |
| Anemone – all parts |
| Anthurium all parts |
| Apricot - leaves |
| Azalea – all parts |
| Baneberry - berries, roots |
| Bird of Paradise - seeds |
| Black Locust Bark - sprouts, foliage |
| Black walnut all parts confirmed reports of death |
| Boxwood - leaves, stems |
| Buttercup - sap, leaves |
| Cactus |
| Calla Lily - leaves |
| California tern roots seeds |
| Cardinal flower – all parts but I have not found that to be true |
| Carolina jasmine – all parts |
| Caladium – whole plant |
| Cherry - bark, twigs, leaves, pits |
| Chenille plant |
| Choke cherry – all parts |
| Colocasia - all parts |
| Coral Plant - seeds |
| Croton - seeds |
| Daffodil - bulbs |
| Datura - all parts |
| Day lily – very poisonous to cats |
| Delphinium – all parts |
| Death Camas - all parts |
| Dumbcane (dieffenbachia) – all parts |
| Digitalis – all parts |
| Easter lily - very poisonous to cats |
| Elephant's - ear all parts |
| Eggplant - all but fruit |
| Elephants Ear - leaves, stem |
| English Ivy – all parts |
| Foxglove – all parts |
| Gloriosa lily – all parts |
| Hemlock - all parts |
| Holly - berries |
| Honeysuckle - all parts |
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| Hyacinth - bulbs |
| Jack-in-the-pulpit – all parts |
| Japanese laurel – all parts |
| Indian Turnip - all parts |
| Iris – leaves, roots, rhizomes (We have had water iris in our ponds for years and have not had any problems.) |
| Jasmine - berries |
| Java Bean - uncooked bean |
| Lantana – all parts |
| Larkspur – all parts |
| Laurel - all parts |
| Lily of the valley- all parts toxic to cats |
| Lobelia - leaves |
| Locust - bark,leaves, seeds |
| Locoweed - all parts |
| Lupine – all parts |
| Marijuana - all parts |
| Mayapple - all parts |
| Mimosa – all parts |
| Mistletoe - berries |
| Mock Orange - fruit |
| Morning Glory - all parts |
| Mustard – roots and seeds |
| Narcissus – bulbs |
| Nightshade |
| Oak - acorns, foliage |
| Oleander – all parts |
| Peach- leaves |
| Philodendron – all parts |
| Pine - sap |
| Poinsettia - leaves, flowers |
| Potato - eyes, new roots |
| Privet - berries, leaves |
| Prunus varieties - seeds, some parts |
| Ranunculus - all parts |
| Redwood - sap |
| Rhododendron – all parts |
| Rhubarb - leaves |
| Snapdragon - all parts |
| Snowdrop - all parts |
| Taro – all parts |
| Tiger Lily - all parts, especially to cats |
| Tomato - leaves |
| Trumpet vine – all parts |
| Tulip - bulbs |
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