Pond life - Diarmuid Gavin on how to give your garden that special touch
With the right plants and maintenance, a small body of water will add a special touch to your garden
This summer's garden project at home involves planting up my ponds. I have three of them, rectangular in shape, and they've sat idle for years, not reaching their full potential.
Remarkably they are full of goldfish, which appear to thrive despite the neglect.
I love water in gardens, as still reflective ponds or gushing streams. But they can work in large green houses also. Years ago, when studying in Dublin's Botanic Gardens, I saw a wonderful concrete pool which had been filled with warm water, gently heated by means of a hot house system via huge pipes. Every year in this pond from a single seed was grown a huge plant - Victoria amazonica. Its leaves grow massive and we were always told their substructure could hold the weight of a baby. And a year ago I spied some pictures in newspapers of a few babies floating on these giant water lilies in a Belgian greenhouse.
But most of us will wish to create water features outdoors. And when made, we will wish to plant them. So what will you choose to plant in your newly installed or recently rejuvenated pond? Plants, as well as their decorative purpose, are essential in the pond to create a balanced ecosystem and keep the water healthy and clear.
Firstly, you need plants that provide surface cover with big leaves - this discourages algae and keeps water clear, while also providing cover for fish. You are aiming to cover about half the surface of your pond with these. It's worth noting that aquatic plants can grow very fast. So regular maintenance involving pruning back once a year will be necessary.
But back to the planting. First choice and my favourite of all is the water lily - it has large circular leaves and of course the most exquisite flowers. The most popular variety here are Nymphaea Marliacea 'Albida' - pure white wide fragrant blooms - and Nymphaea 'Carnea', with pale pink fragrant blooms and golden stamens. As well as water lilies, there are many floaters that you simply pop on the surface. Duckweed can very quickly blanket an entire pond and be a nuisance, so just use the native duckweed, Lemna trisulca. Frog-bit (Hydrocharis morus ranae) is a good choice for the small pond and has white flowers, and I would also recommend Stratiotes, water soldiers.
Next you need oxygenators to keep water fresh - these are submerged and through photosynthesis under water provide bubbles of oxygen. Again there are plenty of very invasive varieties so choose carefully so you are not overrun. I would recommend Hornwort (Ceratophyllum demersum), Willow moss (Fontinalis antipyretica) and Water buttercup (Ranunculus aquatilis), as all are easy to keep in check.
If you are aiming to create a natural looking pond, marginal species will soften the edges of a new pool. These will have all their leaves showing, just their roots submerged so these are placed on the shallower shelf at the edge of the pond. The type of plants you can use here are rushes, sedges and grasses and some of the most ornamental aquatics.
Among my favourites are the flowering rush, Butomus umbellatus, the white arum lily (Zantedeschia), the flag iris, Iris Pseudacorus, Iris laevigata, and Pontederia with its attractive blue spikes of flowers.
If excavating for a pond is too big a project for you, you can always use a pot or a barrel - make sure it has no drainage holes and if using a terracotta pot, paint with a waterproofing yacht varnish inside. Sit plants in their pots on bricks so their leaves just float on the surface. Keep it ultra simple and plant Nymphaea tetragona, one of the smallest water lilies, which has white fragrant flowers.
Don't plant any of these non-native invasive species - they easily escape into the wild, into our rivers and lakes and do environmental damage, squeezing out the native species:
- Floating Pennywort (Hydrocotyle ranunculoides)
-Parrot's Feather (Myriophyllum aquaticum)
- New Zealand Pigmyweed also known as Australian Swamp stonecrop (Crassula helmsii)
- Water-primrose (Ludwigia grandiflora)
- Water fern (Azolla filiculoides and Azolla caroliniana)
- Curly water weed (Lagarosiphon major)
- Canadian pond weed (Elodea canadensis)
- Water hyacinth (Eichornia crassipes)
- Water lettuce (Pistia stratiotes)
Healthy pond tips:
In winter, make sure ice does not completely cover pond as this will trap gases. Remove fallen leaves in winter or place fine net over pond to prevent them falling in. Keep a healthy balance of plants - in spring, lift out overcrowded plants.
You have to weed it like any other part of the garden; it will become submerged in green algae and weeds if left untended.
Blarney in Bloom
The Blarney in Bloom Summer Garden Fair returns to Blarney Castle, Cork on Sunday, July 10, from 10am to 5pm. Entry is €5, with children under 12 being free.
The event benefits Irish Guide Dogs for the Blind, and many gardening experts will be in attendance to give inspiring talks and offer garden and plant advice.
There will be plenty of activities on the day, including:
• local crafts
• kids’ interactive gardening area
• specialist plant nurseries
• Irish Seed Savers
• farmers’ market
• craft workshops
• backyard vegetable growing
• bee keeping
• birds of prey
• compost making
• live music