How to grow Utricularia graminifolia

Look closely and you will see the tiny bladder traps that grow along the runners, making Utricularia graminifolia a carnivorous plant.

Utricularia graminifolia is a carnivorous plant native to the tropical regions of South East Asia and India. It is a small aquarium plant with pale green foliage and is commonly used as a carpet plant, forming dense mats that creep across the substrate and hardscape. In stronger light its leaves will not grow more than an inch. However, if it is shaded or does not receive enough light, its leaves can grow to over an inch. It grows tiny bladders that trap tiny micro-organisms that Utricularia graminifolia can digest for nutrients - these traps are too small to affect even shrimp or baby fish. The plant takes a while to acclimatise to the aquarium environment, but once it has, it will grow quite rapidly.

Utricularia graminifolia has a reputation for being a difficult plant to keep in the aquarium, but this is mainly due to poor practices in the hobby. (e.g. planting tissue culture plants in fresh aquasoil immediately after starting a new tank, rather than planting after the tank has been cycled). Utricularia graminifolia has a few specific but easily met requirements - other than that, it is not a particularly demanding aquarium plant.

Utricularia graminifolia has a pale green, almost yellowish green, which contrasts well with plants with darker shades of green. It is a fast spreading foreground plant once established. As it does not need a substrate to grow well, it will creep up low rocky outcrops if given the chance.

The main requirement for growing Utricularia graminifolia is that it prefers to be planted in a matured and biologically stable tank system. Read this page on how tank maturity is defined. The tissue culture version of this plant is particularly susceptible to melting in uncycled tanks. Generally, you will want to plant Utricularia graminifolia after the tank has been cycled or has been running for a few weeks. You can start the tank with other species first. Utricularia graminifolia has difficulty with new or biologically unstable systems, especially tanks where ammonia spikes are common - if your Utricularia sample melts in the tank within days, this is more likely to be the cause than anything else.

Utricularia graminifolia is a delicate plant and should be handled with care. Skill in handling the plant will greatly increase your chances of getting it to establish and grow. Be careful not to break the delicate runners that connect the leaves. Plant in small clumps in the substrate to prevent the plant from floating up. It is important to plant well the first time, as constant disturbance/pulling up and replanting of clumps will damage the delicate plant. Clumps should be as small as possible without damaging the runner/leaf structure of the plant. Carbon dioxide injection should be used to achieve a dense, healthy carpet. However, it can be grown as a floating plant in low tech/non Co2 injected setups as long as there is not too much flow. It can grow in warmer temperatures above 26 degrees Celsius, but will generally have a looser shape compared to growth in cooler temperatures. Poor light and overcrowding will result in elongated leaves.

Once planted in a particular location, Utricularia graminifolia may take some time to establish. Tissue culture plants may take longer to settle and transport than those that have previously been grown fully submerged. The plant can be quite susceptible to algae, so a stable tank that is not prone to algae attack is helpful.

Due to the tendency of tissue culture Utricularia graminifolia to melt in new setups, there are various myths surrounding its growth requirements, none of which are true. The two most common myths are that it needs to be grown in nutrient poor water - that heavy doses of fertiliser will kill it, and that it needs soft water to grow. Whilst the plant is often found in soft water systems in the wild, and its carnivorous adaptation gives it a competitive advantage in nutrient poor systems, neither of these factors are required to grow it well in the aquarium. It will grow well in moderately hard water and will thrive in tanks that are heavily dosed with liquid fertiliser. It also does not require a nutrient rich substrate to grow - it will grow perfectly well floating or directly on bare rock. Its runners will, in time, loosely adhere to coarse hardscapes such as lava rock.

Utricularia graminifolia can be used as an accent to create a different texture in the fore/middle ground. However, as the runners crawl across the ground quickly, it can be difficult to keep them in place.

Key success factors

• Plant only in recirculating tanks (preferably in tanks that have been recirculating for 2-4 weeks). Tissue culture is particularly sensitive to melting if the tank is not sufficiently mature.

• Overall tank stability and biological maturity matters more than anything else.

• Delicate plant requires careful handling, plant in fixed spot with minimal up rooting/disturbance.

• Not sensitive to the addition of fertilizers, so dosing should be done as it improves propagation rates.

• CO2 improves propagation and acclimatization rates significantly. Can be grow floating or in very shallow water in non CO2 tanks.

• Submerged forms are much easier for most hobbyists to handle than the widely available tissue culture versions.

Pruning and propagation

Individual leaves are connected by a thin and delicate vein. Cutting off half a leaf and leaving a damaged half leaf is an invitation to algae. Utricularia graminifolia should be trimmed by dipping the scissors into the substrate and cutting the runners, then removing the connected leaves and runners completely so that there is minimal organic material left to decompose.

With regard to carpet plants such as UG, there are two main choices that can be made.

1. Trim frequently and deeply enough to allow the existing carpet to renew itself. This means cutting until some substrate is visible - and there is enough space for new growth to root well. Always aim to cut into the densest areas of growth. The disadvantage of this method is that the carpet can (and should) look a little thin after trimming, and many less experienced aquarists are extremely reluctant to cut a carpet when it looks perfectly grown in. This method also requires much more regular work.

2. Wait until the carpet is really dense before making a large trim. The risk of this is that the lower parts of the carpet will consist of very old growth, which may already be deteriorating, and this can result in most of the existing plant mass floating up. Another bad scenario is that much of the growth may be unhealthy due to overcrowding - leading to algae and other problems. This method often means that a major trimming will probably involve some replanting of fresh top growth, which will take longer for the carpet to recover. The tank as a whole will experience greater fluctuation with this method.

In summary, the choice is between light, frequent trimming and deep, infrequent trimming (with some replanting).