We often like traditional aquariums because we just want to enjoy nicely decorated tank. It does not matter if the plants we have are long or short daylight. Our aquarium is usually illuminated for 12 hours a day and therefore the night lasts also twelve hours. Light conditions are similar to the tropics. Plants growing in the tropics are mostly short daylight plants. In addition, we multiply our aquarium plants rather occasionally and the length of the light is intended only for optimal growth of plants.
In moderate climates, in summer when vegetation occurs, the night is short and the day is long. In temperate climates there are plants of the long daylight. Long daylight plants bloom when the day is long. Long day (short night) is the time when the plant of long daylight blooms.
The process of plant’s growth can be perfectly controlled to achieve what we want. We can cause the plants to bloom and produce seeds or tubers and rhizomes. To do this we need to know if our plants are short or long daylight’. Then we can set lighting conditions so that plants give us what we want to.
For example, the Lizard ‘s Tail (Saururus cernuus) blooms when the day is long and the rhizomes are produced when the day is short. Lizard is a typical plant of a long daylight. We can use this advantage multiplying it vegetatively through fragmentation of shoots during Summer. At this time, Lizard’s Tail grows intensely.
In autumn when the day is short, the Lizard’s Tail, in accordance with its nature, begins to prepare itself for the winter. Thus it release a lot of underground rhizomes. Rhizomes are a great material for multiplying this plant. And so in winter you can spread Lizard’s Tail from rhizomes.
Sagittaria sp. behaves similarly. In Summer, when the day is long, it spreads a lot of young plants. Also ,when the day is long, it blooms and gives full-valued seeds, of course, when it reaches the surface of the water. If it is planted deeply, it will not flowers but only releases a lot of young plants. During Autumn, when the day is short, Sagittaria produces tubers. The tubers enable this plant to survive winter. The whole plant is regenerated from the tuber in Spring. This aspect can be used in the daily practice of propagating aquarium plants.
Other plants that are commonly planted in aquaria are Echinodorus species Most of them are plants of long daylight.
They grow very intensely during Summer and produce many new leaves and flower shoots. After blooming they produce seeds. Due to the fact that Echinodorus species are able to release flower shoots above the water, we can easily multiply them. Increasing gradually the length of the light from 12 to 15 hours a day is everything we should do.