Flower Cultivation Techniques: Special Water Requirements Affect Flower Growth and Development
Water is an important raw material for photosynthesis in flowers. Nutrients in the soil can only be absorbed and utilized by flowers when dissolved in water; flowers rely on transpiration from their leaf surfaces to regulate their own temperature, which is also mainly the effect of water. Therefore, without water, flowers cannot survive. Potted flowers mainly rely on artificial watering to supply water, so whether watering is appropriate is extremely important. In the process of flower cultivation and management, it should be flexibly controlled according to the water requirements at each stage.
(1) Different flower species have different water requirements
The amount of water a flower needs is related to the moisture conditions of its place of origin. Flowers native to tropical and tropical rainforest regions need more water, while flowers native to arid regions need less water; flowers with large, soft, smooth, hairless leaves need more water, while flowers with small, hard leaves that have a waxy layer or densely grow fine hairs need less water. According to the water requirements of different flower species, they can be divided into four categories.
1. Aquatic flowers
Flowers that grow in water areas or swamps for a long time, such as lotus, water lily, Victoria water lily, purple loosestrife, etc. These flowers have well-developed aerenchyma tissue in their bodies, through which the roots exchange gases with the stems and leaves above, so they are suitable for growing in water.
2. Wetland flowers
Flowers that need to grow in moist environmental conditions, such as ferns, calla lily, Philodendron, Monstera deliciosa, etc. These flowers need large amounts of water and relatively high air humidity during their growth period; otherwise, they will grow poorly or even die. In cultivation and management, the principle of "better wet than dry" should be followed.
3. Xerophytic flowers
Flowers that can grow and develop normally only under arid conditions, such as cacti, Sedum, etc. These flowers have developed morphological structures and physiological adaptations suited to arid climate ecological environments, and therefore have strong drought tolerance. Most of these flowers have well-developed root systems, high cell concentration, and high osmotic pressure; their leaves become smaller or degenerate into needle-like or bristle-like forms or become fleshy, with leathery or waxy epidermal layers and fine hairs; their stomata are few and small, and their stems are fleshy and succulent, all of which greatly reduce water loss from the body. In cultivation, the principle of "better dry than wet" should be followed for these flowers.
4. Mesophytic flowers
The water requirements of these flowers fall between those of xerophytic and wetland flowers. Most open-field flowers belong to this type, such as China rose, chrysanthemum, tree peony, tulip, etc.
(2) Water requirements of the same flower species at different growth and development stages
The same flower species has obvious differences in water requirements at different growth and development stages. During seed germination, more water is needed for the seeds to swell and sprout; generally, the water absorption of seeds is 50%-100% of the seed weight. After the seeds germinate and emerge, because the root system is weak and distributed relatively shallowly in the soil, the drought resistance is relatively weak, so the soil must often be kept moist. During the seedling growth period, water should be properly controlled to promote root development; too much water at this stage will cause excessive growth. When entering the flower bud differentiation stage, water should be properly reduced to control stem and leaf growth and promote flower bud differentiation. The bud pregnancy and flowering stages need more water, and after the flowering period the water requirement decreases. For ornamental flowers, watering should be reduced during the flowering period to prolong the flowering time as much as possible; for ornamental fruit flowers, more water should be given during the flowering period to promote fruit set.
The impact of water on flower cultivation
The impact of water on flower cultivation
1. The significance of water for flower growth
All life activities of flowers must involve water. This is because: water is the main component of flower cells, and generally 70%-90% of the fresh weight of flowers is water; water is one of the main raw materials for photosynthesis in flowers; nutrients in the soil can only be absorbed by flowers when dissolved in water; the flow and evaporation of water play a very important role in the transport of nutrients and the regulation of temperature.
2. Water requirements of different types of flowers
According to the different water requirements of flowers, flowers are usually divided into the following 5 categories:
(1) Aquatic flowers: flowers that need to live in water, such as lotus, water lily, Victoria water lily, etc.
(2) Wetland flowers: flowers that need to live in moist places, such as Monstera deliciosa, calla lily, calla lily, and other Araceae plants; Tradescantia zebrina, Tradescantia pallida, and other Commelinaceae plants; Adiantum and other ferns. If this type of flower lacks sufficient water, it often grows poorly or even dies. Therefore, watering should follow the principle of "better wet than dry," and the pot soil should often be kept moist, but water must not accumulate, otherwise it easily causes root rot.
(3) Mesophytic flowers: flowers that need to grow in moist soil, such as pomegranate, China rose, Aglaia odorata, hibiscus, clivia, rhapis palm, spider plant, begonia, annual and biennial herbaceous flowers, and bulbous flowers. The vast majority of flowers belong to this type. For these flowers, the principle of "see dry, see wet" should be followed in water management.
The so-called "see dry" means that after one watering, wait until the soil surface turns white and the surface layer of soil is dry before watering a second time; never wait until the pot soil is completely dry before watering.
The so-called "see wet" means that each watering must soak through, that is, until water seeps out of the drainage holes at the bottom of the pot. Do not give "half watering" (that is, wet on top and dry below), because for a vigorously growing potted flower, most of its root system is concentrated at the bottom of the pot, and half watering is equivalent to not watering at all.
Using the "see dry, see wet" watering method can ensure the oxygen needed for root respiration and is beneficial to healthy flower growth.
(4) Semi-drought-tolerant flowers: some evergreen flowering trees originally from high mountains. Although the local air humidity is very high, the mountain rock soil layer is very thin, and it is mostly humus soil formed after the decay of dead branches and fallen leaves of forest trees, creating good aeration conditions for root growth. In order to survive the dry season in tropical and subtropical regions, these plants must have drought resistance under the condition of a very thin soil layer in order to survive. Therefore, most leaves are covered with a relatively thick waxy layer, such as camellia, sago palm, southern magnolia, etc.; some plants have leaves covered with fine hairs, such as geranium, rhododendron, etc.; and some plants have become needle-like leaves, such as asparagus fern, etc. Some perennial evergreen herbaceous flowers have thick fleshy roots, with no distinction between main roots and fibrous roots, and are not lignified. The roots can store relatively more water, and respiration is also quite vigorous. If the pot soil contains too much water, it is extremely unfavorable to the respiration of the fleshy roots and often causes root rot. This is the case for clivia, bird of paradise, orchids, and the like; they can resist 2-3 days of absolute drought without wilting.
For this type of semi-drought-tolerant flower, the principle of "water thoroughly only when completely dry" should be followed in water supply. That is to say, do not water if the pot soil is not completely dry, and if watering, water thoroughly at one time.
(5) Drought-tolerant flowers: flowers that can survive under arid conditions, such as cacti, Sedum, Agave, Echeveria, etc. These flowers are native to places that are often short of water or seasonally short of water. Some have leaves that have degenerated into spines, and some have enlarged stems and leaves that can store large amounts of water, so they can endure drought, but they are afraid of waterlogging. Too much watering easily causes root rot, stem rot, and even death. Therefore, watering should follow the principle of "better dry than wet," and it is better to keep the pot soil on the dry side.
Temperature requirements for home flower cultivation
Among various environmental factors, temperature is one of the important environmental conditions affecting flower growth and development. All life activities of flowers can only proceed normally under certain temperature conditions. The level of temperature directly affects the growth and development of flowers.
There are many kinds of flowers, with different places of origin, and their temperature requirements are also different. The growth and development of each kind of flower has certain temperature requirements. Different flower species and different climate types of origin also have different temperature requirements. If the adaptable temperature range is exceeded, growth will be damaged, or even death will occur.
In greenhouse cultivation, it is proposed to divide greenhouses according to the winter temperature level into high-temperature greenhouses (18-30°C), medium-temperature greenhouses (12-20°C), low-temperature greenhouses (8-16°C), and cold rooms (0-10°C). Flowers of different temperature types should be placed in corresponding greenhouses for cultivation. In home maintenance and management, due to limited conditions, although they cannot be distinguished too clearly, flowers that prefer high temperatures and flowers that prefer cool temperatures should still be separated according to the needs of the flowers.
Flowers native to tropical regions prefer high temperature and high humidity. When cultivating these flowers, the winter nighttime temperature should not be lower than 18°C, and the daytime temperature should be above 25°C. Such as Phalaenopsis, poinsettia, ornamental bromeliads, Dieffenbachia, etc. When the temperature drops below 15-10°C, their normal physiological activities are affected, the absorption capacity of the roots decreases or stops, and the aboveground parts show wilting of young branches and leaves, and old leaves turn yellow and fall off. If the low temperature lasts for a short time, they can still recover; if it lasts a little longer, it will cause the plant to die.
For flowers that prefer relatively high temperatures, such as orchids, Monstera deliciosa, Philodendron, calla lily, ferns, Calathea, Syngonium, Peperomia, etc., when the winter temperature is too low, black spots appear on the leaves, and the leaves curl, shrink, turn yellow, or even fall off, leading to plant death. For flowers that prefer relatively low temperatures, if the winter temperature is too high, the plants will not be able to enter full dormancy and will waste nutrients, thereby affecting growth and flowering the following year.
High temperatures can also cause harm to flowers. When the surrounding environmental temperature exceeds the maximum temperature that flowers can tolerate, it will inhibit the normal life activities of flowers. A high-temperature environment can cause proteins in cells to coagulate and denature, chloroplasts to be destroyed, and photosynthesis to stop; high temperatures can also increase respiration and increase nutrient consumption. In dry climates, excessively high temperatures can cause stomatal dysfunction, massive loss of water from the flower body, and death of leaves and branches, and in severe cases cause plant death. In order to avoid the harm of high temperature and drought, in hot summer it is necessary to provide shade, ventilation, and sprinkle water on the leaves or around the plants to lower the temperature and increase humidity.
Diurnal temperature variation also has a relatively large impact on flower growth. Within the suitable temperature range, the higher the daytime temperature, the more favorable it is for plant photosynthesis and the more nutrients synthesized; the lower the nighttime temperature, the less nutrients consumed, and the more favorable it is for the plant's own nutrient accumulation. That is, within the suitable temperature range, the greater the day-night temperature difference, the more favorable it is for growth. It should be noted that when growing flowers at home, it is essential to avoid nighttime temperatures being higher than daytime temperatures; otherwise, growth will be severely inhibited, causing the plant to suddenly die for no apparent reason.