Pond plants and hydroponics


Fish ponds. Say goodbye to Aquatic Soil and hello to Hydroponics.

I have been a water garden designer for more than 15 years. It has always been recommended water garden and aquatic pond plants be potted in aquatic soil.

five steps
Aquatic soil is the ONLY successful way to grow pond plants. RIGHT?

No, there is an alternative.

If you have a fish pond with a pump and filter my tried and tested easy alternative could change how you pot and re-pot your pond plants forever.

To find out more about the standard aquatic soil method read the RHS advice on Pond planting.
My personal opinion is that aquatic soil should only really be used to plant natural and wildlife ponds that have no pump/filter unit or running water.

I believe the aquatic soil method is perfectly acceptable for the types of ponds I have mentioned but, I do not agree this is the best way to grow plants in today’s modern fish pond or water feature. Read on and I will show you an alternative planting technique that has produced results for me since I first became a water garden designer.

My main problem with aquatic soil is that it can cause the water to discolour, the clarity differs depending on the pond. It can look similar to whisky or at worst dark brown. Another negative is over time the aquatic soil can leach out of the basket. The effects are very frustrating for the water gardener. You might argue that this doesn’t happen all the time. My answer to that is that it does happen enough for the need for an alternative.

Common assumption,
“Don’t the plants need the soil for food and nutrients and to grow?”
My answer, No.

Aquatic soil is purposely produced to contain low nutrient levels or slow release. This is done to avoid overloading the ponds Eco-balance. Normal nutrient rich soil can cause algae blooms and water quality related fish loss to name a few common problems.

Today’s modern fish ponds often have a combination of pumps, UVs and filters. The pump and filter equipment has the ability to circulate a ponds water volume every hour or two. The turbulence created by pumping water increases the available oxygen levels and encourages good pond bacteria. This is very beneficial to the pond in general but does not always work well alongside plants potted in aquatic soil. Water clarity and soil loss can happen fairly fast in ponds with moving water. The dark brown water created by this can be very difficult to eradicate even for ponds with a pump and filter.

Tip, Carbon filter media bags and fine particle filter matting is your best bet if you are going to try (Good luck).

Water Scenes Hydroponic Planting Method.

I have always used an alternative method to grow successful plants without the risk of causing water discolouration or empty plant baskets. In fact this method uses silt and nutrients in the pond instead of adding to it. I have since discovered that this method is identical to or is the hydroponic method.

The rules of Hydroponics.

Hydroponics is the method of growing plants or fruit without the use of soil. Traditionally plants use soil as a source of nutrients and minerals. The hydroponic method replaces the need for soil by adding these nutrients to highly oxygenated water. The plants growing substrate is replaced by rock, gravel or pebbles. This encourages the root system to grow bigger and much denser. The improved route system has the ability to absorb more nutrients thus allowing the plant to grow bigger and faster.

To find out more on hydroponics visit Wikipedia Hydroponics Overview

The hydroponic growing method works perfectly with pond plants and is very easy to do. I will show you how further on.

To convert your pond plants to a hydroponic system you will need.
Fish pond.
Pump and filter system.
Aquatic baskets.
Pond Plants, if you are re-potting do not add any soil at all. A small amount of soil is permissible in small baby plants bought from your garden center or aquatic retailer.

The plant needs to have a healthy amount of route, plant body or tuber and some foliage or emerging leaves.

I am re-potting a lily on this occasion but this principle applies to all pond plants.

Pond lily to pot.

Step 1
Place the plant in the basket make sure the root covers the bottom as much as possible.

Lily in basket ready to be potted

Step 2
Fill the basket half to a quarter with gravel and then tease the plant to the center of the basket, it should now hold in place.

Pond lily in pot

Step 3
Now fill the basket to the top with gravel.

Pond lily in basket.

Step 4
Make sure you rinse the gravel thoroughly as this can cause the water to discolour and harm the fish.

Pond lily's in baskets

Step 5
Place your newly potted plants back into the pond and leave.
That’s it; you have now converted your fish pond to a hydroponic plant system.

Pond plants in empty pond

Do I have to add nutrients?

Feeding fish with pond food supplies the fish pond ecosystem with enough nutrients in the water for all the plants in your pond. Simply replace your aquatic soil for pea shingle gravel and just see what happens. It’s also worth considering as pea-gravel tends to cost half the price of aquatic soil.

As I have explained, replacing soil for gravel allows more oxygen to be absorbed by the root system resulting in bigger and healthier plants. This works because gravel is a very porous growing medium and lets the oxygenated water pass through. Aquatic soil does not do this as the soil is fairly compacted so can’t absorb as much oxygen.

Supplying oxygen to the plant roots system promotes a very thick and healthy root. Having a large root system allows the plant to absorb more nutrients.

Over time the gravel will become full of silt and will no longer be considered as hydroponic, however by the time this happens the root system will have reached the outside of the basket which will then continue to absorb the abundance of oxygen and nutrients that way.

Because the gravel does not leech into the water the ponds overall clarity is greatly improved.
I know this method might seem risky if you are to believe what every other pond plant and horticulture specialists advise but why not try it yourself. I know you will be presently surprised.

Another article you may find interesting is pond plants for beginners.

Water Scenes are a specialist water features and water garden design company. We are experts at combining the design and installation process involved in creating bespoke water features. We have completed 100s of successful projects across the country. If you would like to find out more visit our about us page or contact us.

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