Moisture requirements for flower cultivation
Water is an important raw material for photosynthesis in flowers. Nutrients in the soil can only be absorbed and used by flowers when dissolved in water; flowers rely on transpiration through their leaves to regulate their own temperature, which is also mainly a function of water. Therefore, without water, flowers cannot survive. Potted flowers mainly depend on artificial watering for their water supply, so whether watering is appropriate is extremely important. In the process of flower cultivation and management, it should be handled flexibly according to the water requirements at each stage.
(1) Different types of flowers have different water requirements
A flower's water demand is related to the moisture conditions of its place of origin. Flowers native to the tropics and tropical rainforests 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 dense fine hairs on the surface need less water. According to the water requirements of different types of flowers, they can be divided into four categories.
1. Aquatic flowers
Flowers that grow in water or marshy areas for a long time, such as lotus, water lily, Victoria water lily, purple loosestrife, etc. These flowers have well-developed aerenchyma in their bodies, through which the roots exchange gases with the stems and leaves above, so they are suited to growing in water.
2. Wet-loving flowers
Flowers that need to grow in moist environmental conditions, such as ferns, calla lily, philodendron, monstera, etc. These flowers need a large amount 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. Drought-tolerant 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; the epidermis is leathery or has a waxy layer and fine hairs; stomata are few and small, and the 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 drought-tolerant and wet-loving flowers. Most open-field flowers belong to this type, such as Chinese rose, chrysanthemum, peony, tulip, etc.
(2) Water requirements of the same flower at different growth and development stages
The same flower 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 shallowly in the soil, its drought resistance is relatively weak, so the soil must be kept moist regularly. During the seedling growth period, water should be controlled appropriately to promote root development; too much water at this stage will cause excessive growth. When entering the flower bud differentiation stage, water should be appropriately reduced to control stem and leaf growth and promote flower bud differentiation. During the bud and flowering stages, more water is needed, and after the flowering period the water requirement decreases. For flowers grown for their blooms, watering should be reduced during the flowering period to prolong the flowering time as much as possible; for flowers grown for their fruit, more water should be given during the flowering period to promote fruit set.
The effect of moisture on flower cultivation
The effect of moisture on flower cultivation
1. The significance of moisture for flower growth
All life activities of flowers must involve water. This is because water is the main component of flower cells; 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, they 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) Wet-loving flowers: flowers that need to live in moist places, such as Araceae plants like monstera, calla lily, and calla lily; Commelinaceae plants like inch plant and purple heart; and ferns such as maidenhair fern. 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 potting soil should be kept moist regularly, but it must not become waterlogged, otherwise root rot is easily caused.
(3) Mesophytic flowers: flowers that need to grow in moist soil, such as pomegranate, Chinese rose, Aglaia odorata, Chinese hibiscus, clivia, broadleaf lady palm, spider plant, begonia, annual and biennial herbaceous flowers, and bulbous flowers. The vast majority of flowers belong to this type. For this type of flower, the principle of "dry-wet cycle" should be followed in water management.
The so-called "dry" means that after one watering, when the soil surface turns white and the surface layer of soil dries, it is time to water a second time; one must never wait until the potting soil is completely dry before watering.
The so-called "wet" means that each time you water, you should water thoroughly, that is, until water seeps out from the drainage hole at the bottom of the pot. Do not give "half watering" (that is, wet on top and dry at the bottom), 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 "dry-wet cycle" 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 and shrubs native to 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 by 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 of their leaves have a relatively thick waxy layer, such as camellia, sago palm, and southern magnolia; some plants have leaves covered with fine hairs, such as geranium and rhododendron; and some plants have needle-like leaves, such as asparagus fern. Some perennial evergreen herbaceous flowers have thick fleshy roots, without distinction between taproots and fibrous roots, and are not lignified. The roots can store relatively more water, and respiration is also quite vigorous. If the potting 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, and orchids. 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 unless the potting soil is completely dry, and when watering, water thoroughly at one time.
(5) Drought-tolerant flowers refer to flowers that can survive even under arid conditions, such as cacti, sedum, agave, echeveria, etc. These flowers are native to places that frequently lack water or have seasonal water shortages. Some have leaves that 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 potting soil on the dry side.
Temperature requirements for household 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 proceed normally only under certain temperature conditions. The level of temperature directly affects the growth and development of flowers.
There are many kinds of flowers from different places of origin, and their temperature requirements also differ. The growth and development of each kind of flower has certain temperature requirements. Different flower types and different climate types of their places of origin also lead to different temperature requirements. If the adaptable temperature range is exceeded, growth will be harmed or even the plant will die.
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 household maintenance and management, due to limited conditions, although they cannot be distinguished too clearly, flowers that prefer high temperatures and those 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 nighttime temperature in winter should not be lower than 18°C, and the daytime temperature should be above 25°C. Examples include Phalaenopsis orchids, poinsettia, ornamental bromeliads, dieffenbachia, etc. When the temperature drops below 15-10°C, their normal physiological activities are affected, the absorptive capacity of the roots decreases or stops, and the aboveground parts show wilting of young branches and leaves and yellowing and falling of old leaves. If the low-temperature period is short, they can still recover; if it lasts a little longer, it will cause the plant to die.
For flowers that prefer relatively higher temperatures, such as orchids, monstera, philodendron, calla lily, ferns, Calathea, Syngonium, and peperomia, 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 lower temperatures, if the winter temperature is too high, the plants will be unable 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, damage chloroplasts, and stop photosynthesis; high temperatures can also increase respiration and increase nutrient consumption. Under dry climate conditions, 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 summers it is necessary to provide shade, ventilation, and sprinkling water on the leaves or around the plants to lower the temperature and increase humidity.
Diurnal temperature variation also has a relatively large effect 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 are synthesized; the lower the nighttime temperature, the less nutrients are consumed, and the more favorable it is for nutrient accumulation in the plant itself. 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 and the plant may suddenly die for no apparent reason.