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Growing for success | Water you waiting for? Control pests and choose water plants wisely
Larry Smith and the Riverside Gardens team talk all things pots, plants and pruning in their weekly gardening column.
With all the heat last week, I thought I should probably touch on watering systems and how to best water your garden, but with all the rain since, it seems a bit off-topic.
So, I might let that go until another week.
A word of caution, though: with the rain, warm weather and high humidity comes a huge array of pests and diseases that thrive in this type of weather, particularly moulds, mildews and other fungal problems.
Be sure to keep an eye out and address any issues before they get a hold.
If you are not sure what is causing your problem, bring a small sample in a zip-lock bag, and we will see if we can identify it for you.
My second topic for this week was water gardens, including water plants.
Water plants will be loving this weather, especially since many of them have been sitting dormant or semi-dormant over winter and are now in a strong growth stage, with the perfect conditions to thrive.
A few of the popular water plants can become a bit weedy, so care should be taken if your pond flows into or has access to natural waterways.
Be sure to choose plants that are not going to become an environmental problem down the track, even if they are native.
Water gardens require a bit of work to maintain, especially if you introduce fish into the mix.
But once you have the right balance of water plants, surface cover, water movement, and the number of fish all working together, things become a lot easier.
Water plants can be roughly grouped into a few types, depending on their position in the pond.
There are submerged plants such as Myriophyllum papillosum (Ruby Stem Milfoil) and Egeria densa (Elodea water weed).
These grow happily underwater or trailing along the surface and are great oxygenators.
Due to their quick growth rate, they are also good at removing nitrates from the water.
Then there are floating plants such as Rainbow Nardoo (a native with four-leafed clover-like foliage) float with varying coloured foliage, from light green to rustic brown, and water lilies, with their circular leaves and showy flowers.
These create surface cover and offer protection and shade for fish and frogs to hide from predators.
They also reduce the amount of sunlight in the water, which algae depend on to grow.
Emergent plants such as Pickerel Rush (Pontederia cordata) and dwarf Papyrus Grass (Cyperus prolifera) offer another layer of protection and hiding spots for fish and frogs.
They help limit erosion of the banks and encourage insects such as dragonflies to your pond.
Bog plants such as Acorus gramineus and Houttuynia cordata (Court Jester) stabilise the banks, filter and absorb nutrient run-off from the garden and are good at extracting nitrates from the water.
All these plants play an important part in your pond’s ecology and will go a long way to helping you control problems such as algae.
Algae are caused by many factors, including too few beneficial bacteria, not enough plants or a poor mix of plants, excess nutrients (either from fertiliser, overstocking of fish or decaying matter in the water), warm shallow water with little shade, or simply an under-established ecosystem.
Not all algae are bad, but some, such as string algae, can get out of control quickly, destroying the pond balance and killing any fish and frogs.
There are several solutions you can use to bring algae back in check, but I would suggest natural methods such as Bio Natural 3-in-1 Algae and Sludge Treatment or Pondmax String Algae Natural Treatment, which use plant extracts to do the job.
There are also a range of filter systems that can help keep your pond in check and circulate the water.
Three-in-one biological filters are best suited for this, particularly if you are thinking about having fish in your pond.
These work by passing water through a series of sponges in a canister containing aerobic bacteria that feed on the nitrates in the water.
The water is then passed by ultraviolet light to ensure the elimination of any algae or pathogens left after the process.
This is the type of system we use in the garden centre in our water plant sales area, with great success, even though it is overstocked with fish.
Now is the best time to be thinking about stocking your pond with plants because they are growing quickly, there is the biggest range available and they are looking their best.
So, drop in and have a look, and we can help with the selection of the right plants for the job.