Propagation by cuttings.
Propagation using stem cuttings is the most accessible method. Most aquarium plants form branched or straight stems. They feature nodes, from which leaves branch out in various arrangements, and internodes. Most stem plants in an aquarium are characterized by the presence of lateral branches emerging from the leaf axils. Aquarium plants with long vertical or creeping stems are very easily propagated this way. Cuttings should be taken from healthy, well-developed specimens. It is best to separate plants using scissors or a sharp knife just below a node, where roots will later form. Additionally, leaves on this node are removed to prevent rotting in the substrate.
Long-stemmed plants need to be cut not only for propagation. Many of them stretch out significantly and lose their decorative qualities. Therefore, by cutting the top of the stem, the lower part is forced to bush out. The top of the plant should be planted in front of the untouched lower part of the stem, thereby preserving the aquarium’s interior layout. When doing this, try to make the height of the plants increase stepwise from front to back.
As plants reach the water surface, they form aerial shoots, while the leaves in the lower part of the stems die off due to a lack of light, lose their appeal, and branch out, getting in each other’s way. Therefore, the tops of plants that have reached the surface should be cut off. This can be done in two ways: if you want to multiply the planting, the stems are cut approximately in half, and the cut ends of the shoots are planted again. Two or more shoots are added to the remaining planting, which, upon reaching the water surface, are also cut and replanted. If you do not want to propagate the plants, but merely enjoy their beautiful appearance, the stems should be regularly pulled out, shortened from the bottom, and the top part replanted. After some time, the lower parts of the stems stop producing shoots and can be removed.
Spring is the best time for taking cuttings. Over the summer, the cuttings manage to develop into lush plants. If necessary, plants can be propagated by cuttings year-round, but rooting and development will be slower. Most aquatic and marsh plants with long stems bearing leaves of various shapes are suitable for propagation by cuttings. Besides Hygrophila and Nomaphila, stem division can be used to propagate Ludwigia, Bacopa, Limnophila, Cabomba, Ceratophyllaceae and Myriophyllum, Alternanthera, and many other plants. Plants that float in the water column, such as Elodea, are also propagated by cuttings. In this case, the decaying bottom piece of the mother plant’s stem is discarded.
A good method to quickly propagate long-stemmed plants is to press them to the substrate with a stone, and they will rapidly release numerous vertical shoots from the stem. Some species form roots without being planted in the substrate, so it is enough to secure them with a glass hairpin or flat stones on the substrate and wait until they root.
A cutting is a part of a plant shoot with an elongated stem suitable for vegetative propagation. The stem is divided into parts so that a 10-15 cm cutting has 3-4 whorls or pairs of leaves. With an alternate leaf arrangement, stem cuttings should have at least four to five leaves. Using scissors, separate the tip from the stem — the apical cutting, which should consist of at least 3 nodes, and then, after removing the leaves from the lower 2 nodes, plant it into the substrate so that the leafless nodes are covered by it, as they will produce roots. The apical cutting begins its growth the fastest.
If the plant has formed a lateral shoot, these side branches can be cut off and used as cuttings. The cutting is separated directly above the node from which the lateral shoot departs. In addition, the lateral shoot itself can be separated as a cutting if it has formed at least 3 nodes. Stem division can be used to propagate Bacopa, Ludwigia, Cabomba, Limnophila, Hygrophila, Lemonophils, Ceratophyllaceae, Alternanthera, Myriophyllum, and many other species.
To obtain new plants, it is enough to pinch off a shoot and bury its lower part with one or two leaves. The shoots quickly form roots and begin to grow. To accelerate the formation of lateral shoots, you can separate or pinch the top of the plant. If the plant is large enough, in addition to the apical cutting, you can separate the next section of the stem — a shoot cutting with at least 4 nodes, and after removing the leaves from the lower 2 nodes, plant it in the substrate. The shoot cutting is the last one to start growing.
Such cuttings can be planted directly into the aquarium substrate, making sure to bury the lower whorl or leaf. Under favorable conditions, young roots will form at the base of the first leaf within a week. Under favorable conditions (clean, oxygen-rich water, adequate light and warmth), the cutting forms leaves and roots and gradually develops into an independent plant.
If the upper part of the stem was taken, the apex will generally start growing first. If the cutting is planted in the same aquarium or in a container with identical water, there is practically no growth pause. When conditions change, a short pause occurs in the growth of apical cuttings of long-stemmed plants. The more the characteristics of the new water differ from the old ones, the longer the growth pause may be. If the cuttings of long-stemmed plants are taken from the middle section, when planted in a new substrate—even in the same aquarium—their growth is always noticeably delayed.
Simultaneously with the young roots forming at the base of the lower leaf, young shoots—usually two or three—develop from the growth buds in the axils of the upper leaves. Growth rate recovers once the young shoots gain sufficient mass. The mother plant left in the substrate, possessing a developed root system, will also soon begin to produce lateral shoots at the nodes. The remaining long stem produces several lateral shoots.
