TURTLES. They eat waterlilies. Some people will not be persuaded of this. Recently a client said to me, "My pond is pretty big, and there is only one turtle ... so let's put in a dozen of your waterlilies; that way, there won't be too much damage to any one plant." Sounds reasonable right? So, against my usual good sense, I installed a dozen of my finest waterlilies, all of which were completely eaten in two weeks. It was as if there never had been any lilies at all. Moral: There is never just one turtle.
TOADS are very common even in the heart of the city (New Orleans), although people insist on calling them frogs. Frogs, which tend to be green and smooth, live in and around the water year round. Toads, which tend to be brown and bumpy, only go to the pond to lay their eggs. Frogs make nice, cheerful "rub-it" sounds. Toads sound like an electric motor about to bum out. Frogs are good. Toads are not. If too many toads lay their eggs m your pond, the poison secreted by their tadpoles will kill your fish in three to five days This is the explanation behind many mysterious fish kills every spring and summer, when there seems to be nothing at all wrong with the pond, and all the fish belly-up suddenly. Toads raise such a racket about 10 pm when they are mating, that you won't be able to say you had no warning.
You can either remove the toads at night before they lay their eggs, or remove the eggs with a net the next moniing or remove the tadpoles as soon as they hatch. Obviously, it is easier to remove a dozen pairs of toads from your pond than to remove a zillion tadpoles three days later. Maxim: Hundreds of tadpoles are tolerable, but thousands of tadpoles can be toadally tragic. Also, toads are common, frogs are rare.
While on the subject of reptilian renegades, I would have thought it went without saying that waterlilies and other pond plants are incompatible with ALLIGATORS, even the cute little white ones who live at the Aquarium. So let's all update our list of things you should not put in your pond ...turtles, toads, ducks, crawfish, raccoons, nutria, Golden Retrievers, and especially alligators.
KOI. Another critter you may not want to put in your waterlily pond is the now popular Japanese Koi fish. This large, colorful aquatic version of the weed eater will eat everything, including waterlilies, hyacinths, submerged grasses, etc. While Koi may not be particular about what they eat, they do demand larger & deeper ponds than most of us have and they insist on the highest quality of water at all times. My own Koi were exiled to a friend's pond across the state line when I caught them jumping out of the water to munch on Miss Muffet caladiums.
Really fine Koi are expensive; all of their race are frenetic, fickle, fussy, and sometimes suicidal when they don't get their way. They should be confined to a pond of their own, or fenced off from the more tranquil inhabitants of your water garden. If you are already vexed by Koi, then no doubt they have already trained you never to leave them unfed for even a single day. However, should you decide to sneak out of town for a weekend, you can put a whole head of red lettuce in the pond before you leave. The head of lettuce will stay fresh for days, while the Koi play volleyball with it and rubble it into oblivion. If you still feel guilty about leaving, you can also throw in a bunch of fresh uncooked broccoli as a peace offering. I hope you are paying attention here ... it should be red lettuce (not cabbage!) and raw broccoli. I told you Koi could be fussy.
WATER. City water now has both chlorine and chloramine added to it. This why you cannot just fill a pond with tap water and let it age a few days to make it safe for living things. A pond freshly filled with city water will bum the leaves off a waterlily overnight, and kill fish, snails and other flora and fauna in hours. (You don't drink this stuff, I hope!) Unless you are using untreated well water, you must use a dechlorinating product when you first fill your pond. Products like Shieldex and Instochlor work instantly to neutralize these chemicals and make the water safe. If you are not sure how much dechlor to use, be generous, you can't do any harm by using too much, but you will be very upset if you don't use enough. Once a pond is filled and functioning, you can add fresh tap water every day, up to as much as 10 per cent by volume, and you need not dechlorinate. It would be prudent to keep a spare bottle of Instochlor handy at all times, for that inevitable lapse of good judgment which happens when you leave the hose running in your pond while you run to answer the phone. An hour later, when you discover the flooded patio, you can still save the day by pouring a bottle of Instochlor into the pond, thereby preventing the tragic demise of your plants and fish. And no one will ever know that you did such a foolish thing as to leave your hose running unattended. Best rule of thumb: When in doubt, dechlor . . . and don't drink the water!
While we are on the subject of water, there is a disturbing trend among some pond keepers to become overly interested in the pH of their pond water, adding this or that to raise or lower the pH to some magic number that they assume is desirable. In all the years I have been water gardening, I have never adjusted the pH of a pond. If you are ignorant of what PH is, good; it need not concern you, except to know that water below a pH of 7 is acid, and above 7 is alkaline. A survey of 20 of my ponds revealed a pH range from 6.2 to 7.8, and all plants and animals are fine in all of them. As a rule, ponds which are very clear usually have a pH near 7 or slightly below 7; ponds that are green with algae are usually above pH 7.8. The explanation is simple . . .excess fertilizer from plants or fish dissolves in the water and releases ammonia, which is alkaline. This feeds the algae, which turns the water green. If you have lots of submerged plants like anacharis (Elodea) in the pond, these plants will absorb the ammonia, the water will begin to clear, and the pH will drop closer to 7. This will leave you free to fret about more important matters, like how you can catch those Koi without wrecking your pond, and what fool will take them off your hands? Axiom: Watch the pH in your swimming pool, ignore the pH in your lily pond.
One final pH fact. Do not use new concrete blocks in your
pond to support plants or statuary - they are so alkaline that
they can quickly raise the pH to dangerous levels. Old concrete
blocks which have been exposed to the weather are okay, as are
bricks without mortar.