Aquarium plants from various parts of the world are now widely cultivated, but it makes sense to choose those that would normally grow in the same conditions and habitat as your fish. This means that they are more likely to suit the fish and should thrive in the same environment. Make sure any plants you choose will tolerate the conditions in your tank; those that normally grow in soft water are unlikely to thrive in hard water, and few plants will thrive in a lime-based substrate.
Aquatic dealers should have a good selection of plants available. Alternatively, especially if you are looking for an unusual plant, look in fish-keeping journals for advertisements of specialist mail-order suppliers. Bear in mind that seasonal and other factors may still affect supplies at times, so you may need to be patient if you are seeking a specific species.
Buying aquatic plants
The advantage of obtaining plants locally is that you can inspect them before purchase, then take them straight home with you. There is no risk of delays in the mail or chilling during cold weather as may occur when ordering from further afield. Aquatic plants must be kept moist at all times because their foliage is delicate and highly susceptible to drying out.
When selecting plants, only pick those that look healthy and vigorous. Avoid any that are lanky or with abnormally yellow leaves. In general, it is best to buy quite small specimens – they are more likely to settle in well and thrive in new surroundings compared with a large, established plant.
On arrival home, carefully check each plant for signs of invertebrates such as snails or their eggs, usually a jelly-like mass on the underside of the leaves. These might prove to be unwanted visitors because they may start eating the plants. It is also wise to wash the plants in a solution of aquarium disinfectant, to eliminate the risk of introducing any diseases to the tank.
Some plants are sold in small pots, which may generally be left in place; it may even be advantageous to restrict the plants in this way. Left unconfined, their roots will spread freely through the substrate of the tank; if you have an undergravel filter, the roots may well block it, seriously reducing its efficiency.
In any well-planted aquarium, there is a need for regular maintenance, such as thinning and pruning of the plants as well as the removal of dead leaves. Long-handled, stainless steel scissors are ideal for enabling you to carry out these tasks with the minimum of disturbance to the fish.
Amazon sword plants
Some plants make a special feature in their own right – sometimes described as specimen plants. These include members of the Echinodorus genus, which are usually known as Amazon sword plants. Originating from the Amazonian region, these plants prefer soft water, and are ideal in a tank housing fish from the same part of the world, such as tetras. Take care to check on the species on offer, because some species, such as the broad-leaf Amazon sword (E. blehcri) may grow to about 40cm (16in), making them too tall for many aquaria. Most Echinodorus species have relatively narrow, strap-like leaves, but the spade-leaf plant (E. cordifolius) has much broader foliage. The pygmy chain sword plant tenellus) is an excellent choice for the front of an aquarium, and usually establishes itself readily. It grows to about 7.5cm (3in), but if crowded it tends to grow more upright and so will be slightly taller.
In favourable conditions, Echinodorus grow quickly and soon become established. They are also relatively tough plants, and their fronds are not usually the target of excessive damage by fish. You can propagate them quite easily to create new plants: simply split off runners or plantlets that grow off their stems once these reach a reasonable size.
Cryptocorynes
In the wild, where water levels fluctuate through the year, some aquatic plants are only submerged for part of this time, yet in the aquarium they are generally kept consistently under water. In the case of the Cryptocoryne genus (often known as crypts) from southeast Asia, this serves to slow the plants’ growth, since they develop most rapidly when their leaves are exposed directly to sunlight.
A number of cryptocorynes are potentially too large for the typical aquarium, but the attractive dwarf crypt (C. nevilii) is ideal for the foreground, since it should grow no taller than about 10cm (4in).
Cryptocorynes often prefer a finer rooting medium than that used for the aquarium substrate, so it is best to grow these plants in containers. You can then incorporate the most suitable rooting medium here for them, without affecting the efficiency of the filtration system. Crypts generally dislike root disturbance in any event, so are best obtained in pots, although you may subsequently divide large plants or split off runners when they are more established.
Sagittarias
Sagittarias are another group that will readily grow out of the water. Members of this genus show a considerable range in size, with the largest species growing over lm (39in) tall. The dwarf sagittaria (S. subulata) is a popular choice for aquaria, being suitable for the mid-ground area of a tank. This grasslike plant can reach a height of 30cm (12in); set it in small groups spaced slightly apart to provide dense cover. The level of illumination can affect its coloration, with dwarf sagittarias often developing a reddish hue when grown in brightly-lit conditions.
Vallisnerias
Tall and elegant, vallisnerias (also known as vallis or eel grass) are a good choice for the mid-region or rear of a tank. The spiralled leaf form, twisted vallisneria (V. tortifolia) is often used in the mid-ground, while the taller giant vallisneria (V. gigantea), especially the red form, makes a stunning specimen plant at the back of a large aquarium.
