My cell-phone was stolen recently so I lost the details saved in it. The gist of the enquiry was:-
I have been trying to establish a water-lily pond in my garden without success. The pool is concrete-lined and I spent a fair sum of money on the plants. I stocked it with black native fish for mosquito control only to find that they attacked the lily leaves to the point that they ate them all. I removed the fish, drained the pond, and restocked the pool with lilies only to find that the second time swarms of little black water snails did the same thing. What can I do?
As I haven’t actually seen the fish/snails, some of the answer involves supposition. I suspect that black native fish were catfish. These are gross feeders and eat just about any kind of vegetation – people who breed these fish for the table regularly throw soft leaves into their ponds which are consumed with astonishing speed.
Along with those fish came eggs and/or baby water snails. Drain your pond again and leave it dry and exposed to hot sun for at least a week. This may do for any residual snail eggs, but they may simply lie dormant until conditions are right for them again to proliferate.
When you refill the pond, stock it with ornamental goldfish. If the pond is large, you could even include some of the Japanese Koi Carp. Do not place any plants in the pond just yet. This will mean you will have to regularly feed the fish until you re-stock – also for some time after, until these plants are well-established and growing on strongly.
There are two types of water-lilies – Nymphae spp – commonly grown here. The large flowered lilies also have large leaves – they can be as big as dinner plates. These lilies are essentially night bloomers; the flowers begin to open around 4pm – stay open all night, and as the sun rises higher, will close the flowers until by noon only the furled buds can be seen. These flowers are held well above the surface of the water, unlike European lilies which float on the surface.
The other kind open their flowers above the pond surface during the day and close up at night, but have much smaller flowers and leaves. These too are commonly grown here – especially the purplish-blue variety, a rare color in water lilies. They are available also in white; white with a blue penciling to the petal’s edge; pink, and yellow. Include the sacred lotus (pink and white). Their leaves and flowers are borne on high stems well above water level so they are safe from attack.
Goldfish are members of the Carp family and are essentially bottom feeders. (Not that you would think so when they swarm to the surface at feeding time.) Make a point of feeding them at around the same time and from the same place. Once they get the idea, your tread coming close to the pond will have them waiting for you by the time you reach the water’s edge. They are remarkably good for their size at uprooting lily plants so cover the soil in the pots with large, heavy, river stones.
Provide them with other sources of water vegetation as an alternative diet. Floaters, such as water snowflake, water lettuce, water hyacinth – and submerged plants, such as elodea, cabomba, valisneria. In due course, algae will establish on the pond walls and submerged pots which the fish will also happily graze on. Water hyacinth roots provide an ideal environment for the fish to breed.
When you buy new lilies, keep them in quarantine for a while before placing them in the pond until such time as you can be sure you haven’t also imported more pests. Large plastic tubs or inflatable childrens’ wading pools will suffice. Regularly flush them with fresh water from the garden hose every two days or so. With lotus, plant them in the pots to go into the pond later; be sure that there is always 3-5cm of water above the soil level at all times.
I have seen the smaller water lilies grown in pots which are just above the water level, thereby protecting them from snails and predatory fish. (Yes! – There were catfish in this pond.) They do not grow quite as vigorously as if fully submerged, but they still flower well. Again, it is necessary to have 3-5cm of water above the soil level.
The above solutions should ensure you of success this third time around. Consider also some flood-lighting for the pond so as to enjoy the night-flowering lilies, though they are best seen by moonlight. Please let me know how you do with the above.
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E-mail: gardendoctor08@yahoo.com
