UPDATE ON PANDANUS PLANTS

Pandanus amarillifolius plant that I acquired 8 month ago is now officially "rooted". It took awhile for the plant to overcome dividing and its root system being sterilized with Clorox ® solution. Today, the plants are flourishing. By the way the leaves look and their growth rate, it seems that the plants are getting enough nutrients from the ranchu pond. Although, there is no significant effect on reduction of nitrates yet, I hope in the future as the plants get bigger and grow more roots, it will become noticeable. Just to remind, that the pandanus plants are suspended above the surface of water with their roots developing in the water with no substratum.

For now, it is an attractive addition to the pond and my ranchu seem to like to swim up to the roots and pick an algae growth from them. Oh, and did I mentioned that rice cooked with pandanus leaves tastes so much better!

WATERCRESS? WHY NOT?!

Continuing my ongoing trial and error experience with the pond, I thought, why not watercress? I am still looking for more ways to lower nitrates, besides 100% water changes.

Right now, the pandanus plants (Pandanus amarillifolius) that I have been growing in the ranchu pond are flourishing. I bought two kinds -  tissue cultured small plants eight months ago (see my post "Pandanus Plant") and an adult pandanus 1.5 foot (45 cm) tall, that I divided on three pieces. New roots are developing well and judging by the new growth and color, the plants are getting enough nutrients.

Pandanus plants growing in my ranchu pond

The water is drained to show pandanus root system

To extend my nitrate "elimination", I am now trying out watercress (Nasturtium officinale). This plant is aquatic or semi-aquatic, naturally found in and around freshwater streams. I thought that watercress would be a perfect candidate to grow in my ranchu pond. Being a popular leaf vegetable in my kitchen, I am also looking forward to consuming it.

I started off by germinating watercress seeds in finally cut paper towel. Keeping the substrate very wet was the key. Why cut paper towels? I try to avoid introducing pathogens and any other unwanted elements into my ranchu pond. Any plant's root system that had been grown previously in the soil, I sterilize with bleach. Cut paper towels offer a clean substrate.

After the seedlings developed 2-4 true leaves and a root system, they had been transplanted on pieces of Matala filter media, which I have been using in my bio filter. Matala mats seem to be a perfect medium for using in my improvised hydroponic culture. I hooked strips of Matala to the edge of the pond with hooks made of galvanized wire, so the strips are halfway in the water, allowing only the root system to be submerged. 

Fifteen days later, my watercress plants are growing well. With little time, their root system will come through the Matala mats using up the nitrates and growing succulent leaves for my kitchen. 

PANDANUS PLANT

Not just any Pandanus. There is only one species of Pandanus amarillifolius or Pandan Leaf, as it is commonly known, that is admired and treasured by many in Southeast Asia for its unique quality - aroma in its leaves. When wilted or dried the leafs give out a very characteristic smell. To me it is very earthy, and warm. Closest I can come up with to compare its smells is the smell of expensive basmati rice. The leaves are used to flavor foods and drinks and in addition will give bright green color.

This plant is often cultivated among flooded fields as semi-aquatic, eventually growing up to 6-8 ft (1.8-2.4 m) tall. I got interested in this plant not only for its culinary qualities, but the fact that it can grow in the water. My idea was to use it in my ranchu pond, where it will utilize nitrate, a byproduct of the nitrogen cycle. Besides it is a quite attractive plant to have.

Pandan Leaf plantation in Sri Lanka

I purchased my Pandan Leaf from the plant nursery as a plantlet grown from the tissue culture. After receiving the plant on November 13, 2013, I took it out of the soil and washed the root system. I started to prepare the plant to grow hydroponically in my ranchu pond. I constructed a support from bamboo to hold the plant at just the right depth and to be able to adjust it when water level changes.

Pandan Leaf affixed to a bamboo support showing developed root system

Then I placed the plant in the corner of my ranchu pond, making sure that the roots are covered with water. The plant triple in size since I bought it almost 4 month ago. I expect it to start growing even faster, as the water in the pond is getting warmer. Judging by the growing root system, the plant seems to like its place. Lucky, my ranchu do not try to eat it and occupied with munching on the algae instead.

Pandan Leaf plant in my ranchu pond

One plant was an experiment. Now I need to get more plants of Pandanus amarillifolius to have any effect on the amount of nitrate in the water..