Oxygenating Plants Update
At the end of August 2017 the selling of Elodea crispa (also known as Lagarosiphon major) became illegal. Up to this point, this was the most common species of pondweed sold in the trade.
Elodea crispa became popular due to it's hardy and prolific nature. It would grow in almost any pond, often to the point where it needed removing on a regular basis. It's success has proven to be it's downfall as it has become invasive and started to impact on native habitats. Proof of this has led the UK government to ban the export and sales of this species. This development has left pond keepers and aquatic shops with a dilemma ....... What else do we sell? Hopefully this article will inspire you to try a few other species.
At Parkers we try to stock a good range of these species throughout the spring and summer months. However, variable availability from our suppliers causes the species in stock to change accordingly.
Bunched Oxygenators:
1) Egeria densa - A brazilian Species that does not always do well outside and should be managed carefully as it also has the capability to become invasive.
2) Elodia canadensis - A canadian species that is very similar to crispa in so far as it will grow vigorously for most people and again can be considered potentially invasive.
3) Callitriche Stagnalis (Water Starwort) - British Native - A delicate looking, very attractive species which tends to be available in spring and early summer. It will continue to grow in autumn and winter, but does not do as well when it is really warm. It is easy to grow as long as it is not eaten and is ideal for wildlife ponds. It can be grown as a weighted bunch but will do much better if planted. Water Depth 5cm - 100cm deep
4) Ceratophyllum demersum (Hornwort) - British Native - Beautiful pond weed that can grow easily as a weighted bunch. Hornwort grows very quickly and can occasionally become a nuisance.
5) Potamageton crispa (Curly Pondweed) - British Native - A fantastic oxygenator that looks like a seaweed. This plant can grow from a weighted bunch but will do better when planted in a pot. When established it will grow in depths to 200cm. Always start in shallower water first though.
6) Ranunculas aquatilis (Water Crowsfoot) - British Native - Stunning white flowers and wispy foliage.
7) Hottonia Palustris (Water Violet) - British Native - Will grow in shallow or deep water (5-70cm). Stunning ferny foliage and very pretty lilac flowers. Grows best when potted.
8) Fontinalis antipyretica (Water Fern) - British Native - Lovely short growing, fern-like plant that grows as a carpet across the bottom of the pond. Can grow in most depths of water.
Potted Oxygenators:
1) Lilaeopsis brasilensis (Brazilian Micro Sword Plant) - This short, grassy plant is a great oxygenator that forms a carpet on the bottom of the pond. This species can be slow to start but is a stunner once established. It can be grown at depths of 5cm - 90cm.
2) Hydrocotyle nova zealand (Miniature Pennywort) - A very attractive plant that will grow as a mass of small, round, bright green leaves on the surface of the water. This plant comes only in a pot and should be grown in fairly shallow water between 10-30cm deep.
3) Hydrocotyle sibthorpioides ‘variegata’ (Crystal Confetti) - Really stunning oxygenator with several colours in the flowers. It can grow fairly quickly, forming a mat of leaves on and below the water. Great for gardens and as a trailing plant grown in waterfalls. Grows in water at depths of 0-30cm.
4) Eleocharis acicularis (Dwarf Hairgrass) - Nice little grass-like oxygenator which grows 10-15cm high and needs to be planted 0-60cm deep.
5) Scirpus cernus (Fibre Optic Plant) - Awesome little grassy plant with a white flower spike on every leaf tip. Needs to be kept in shallow water 0-12cm - slow grower so great for small ponds.
6) Ranunculus hederaceus (Ivy Leaf Watercrowsfoot) - Cracking little creeping oxygenator. Produces tiny white flowers. Water depth 0-30cm.
7) Hippuris vulgaris (Mare's Tail) - British Native - Shallow water 20cm or less. This plant has upright, bottle brush stems that are half submerged. All in all, a pretty little plant.
8) Marsilea quadrifolia (Four Leaf Water Clover) - Nice, easy, quick growing species. Water depth 0-30cm. Plant grows to 12cm high.
9) Hottonia palustris (Water Violet) - One of the best! It will grow in shallow or deep water (5-70cm), has stunning ferny foliage and very pretty lilac flowers.
Author and Photo Credit - Parkers Manager Patrick Davies.