Seed propagation of plants briefly. Reproduction by seeds. Seedling care
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All woody plants reproduce in two ways - seed and vegetative.
How do seeds reproduce? Seed propagation is carried out by sowing seeds in a nursery and growing seedlings from them. This method has found wide application in nurseries. It is characterized by simplicity, high productivity, high efficiency. Woody plants obtained in this way have a powerful root system, are viable and durable.
Vegetative reproduction
Vegetative propagation is carried out by plant parts - cuttings, layering, root offspring and grafting. Poplars, willows, currants, tamarix, grapes and other plants, as well as spherical, pyramidal, weeping variegated forms of tree species and seedlings of tree crops are propagated in this way in the nursery.
Reproduction by cuttings
A plant grown from a cutting will be more similar to the parent, in addition, it will take root faster than another that has sprouted from a seed. Not all trees and shrubs can be easily propagated in this way, but for most it is possible.
Cuttings are prepared very simply by separating non-flowering shoots from the plant. The length of the shoots will depend on the type of shrub, but choose material whose nodes (buds) are located as close to each other as possible. We advise you to work with the apical sprout, while removing the apical leaves. Make an incision under the last node, after removing all the leaves. This last knot is then dipped in the freshly prepared rooting powder and then placed in cutting compost (50% compost + 50% peat), or in a grower, or in a pot that can be covered with a plastic bag or other transparent material. Depending on the length of the shoot, there may be other nodes above ground level or below.
Some plants will root very readily if you provide them with a heel. This is a piece of old wood at the base of the cutting, and it is taken from the place where the cutting joined the main stem.
From the part of the stem that remains below the ground, leaves should be removed in order to prevent rotting, and leaves above the ground should be removed to prevent moisture loss. They should be removed carefully with a sharp knife or razor. The topmost leaves remain, but if they are large, they should be halved by making neat cuts with a razor.
Potted soil should be kept moist and out of direct sunlight, even though your plantings will need as much light as possible. Establishment times vary, but the start of new growth from the nodes most often means that the roots have already formed and it's time to plant your plantings in individual larger containers. Some plants, such as roses, root easily from large cuttings that can be planted directly into the ground in a shady spot. The soil should be light and loose, and remember to keep it moist.
Some plants reproduce by shoots cut at the beginning of the year, when they have not yet become woody (reproduction by green, summer cuttings). They should be trimmed with a razor blade or a sharp knife just below the leaf node, so that a stalk 5-10 cm long is formed, depending on the plant. Remove any lower leaves and try to make the cut as clean as possible. If the plant has large, large leaves, they should be cut in half to reduce the inevitable loss of moisture due to evaporation. The end of the cutting should be dipped in rooting accordion and placed in a mixture of garden sand and peat. Until the roots appear, the mixture should be kept moist in a weeder or with a plastic bag.
Other cuttings can be cut when the shoots are already lignified and hard enough (reproduction by lignified, winter cuttings). They are usually cut in autumn, so they are not placed in pots until next year. Lignified cuttings 25-30 cm long are obtained in the fall, cutting off matured shoots of the current year. It is necessary to remove the lower leaves and all soft ends. The lower part of the cutting (7.5-10 cm) should be placed in a pot or a shallow groove and covered with a mixture of garden sand and peat. It is better to protect the cuttings from direct sunlight and do not forget to water. Thin shoots, like those of the barberry, may become deficient in nutrients before new roots are formed: in this case, heeled cuttings should be used and a piece of old wood that contains sufficient nutrients should be cut off. Such cuttings should be placed in pots. A mixed option is the use of semi-lignified - sometimes they are called semi-adult, or shoots of the first year of growth - cuttings that are most often cut in the summer.
Reproduction by layering
Layering is a very simple technique that can be a good means of propagating particularly difficult plants, but it is time consuming. From the parent plant, the stem is bent and fixed under the surface of the earth either with a peg or by pressing down with a heavy stone. In the center of that part of the plant that is in the ground, it is necessary to make a short incision, and bend the top of the shoot up and secure it with a peg. Don't forget to water the shoots. It is difficult to say how long it will take for the roots to appear, in some particularly difficult cases it will take years, but new leaves on the shoot branches will be a sign that the offspring has taken root. After that, the cutting is cut off from the parent plant.
Vaccinations
For a variety of reasons, it is sometimes more convenient to grow a tree or shrub using the so-called rootstock, namely the root and stem of another plant. Maybe the tree you want is growing too fast, so grafting it onto a slower growing rootstock can keep it compact or even miniature. Sometimes it is possible to grow two species on the same plant or get wonderful chimeras.
Division
This method is most often used to propagate herbaceous plants, but a number of lateral offspring shrubs can be propagated by removing part of the entire plant, with roots, and planting the resulting material elsewhere.
Aftercare
Seedlings and cuttings should be planted in good seedling compost. Once they become strong enough, you can transplant them. Don't plant them in pots in winter, cold weather can kill the plant before it starts growing again. It is best to plant them in large pots deep enough for long roots until the plant is large enough to plant in the garden. Plants obtained by propagation by side shoots or division can be planted immediately if they are already large enough.
Most trees and shrubs are heterozygous in their genetic structure, therefore, within the range, plants belonging to the same species and even form, along with biological, morphological and ecological properties, have unequal hereditary qualities. In this regard, a necessary condition for the selection of plants for harvesting seeds is to carry out work related to the testing of seed trees by offspring.
Harvesting seeds from random trees and shrubs that are not typical in terms of clearly expressed qualities of interest to us should be categorically avoided. Should not be used to collect seeds of plants damaged as a result of diseases and adverse effects of the urban environment, resistant to pests. Particular attention should be paid to the need to prohibit the use of seeds from trees with signs of degeneration and advanced age. The offspring obtained from them is characterized by fragility, poor growth, poor resistance to pests and diseases.
With seed propagation of decorative forms, the heritability of individual traits depends on the meteorological conditions of the year.
and pollination conditions. With free pollination, the characteristic signs of purple-leaved forms appear in 60% of plants, variegated - in 20% and dissected-leaved - in 30%. Therefore, a preliminary test for the transmission of certain characters to offspring can be established for individual species and forms only by experience. Reproduction by seeds of forms and species should be considered justified if the trait of interest appears in 40% of the plants.
Fruiting and collecting seeds
The possibility of using the seed method of reproduction depends to a large extent on fruiting, i.e. on whether these species form seeds in a certain area, in what quantity and what quality. The frequency of fruiting in individual species is also important - in many ornamental breeds, the frequency of abundant fruiting is well expressed and a large seed yield occurs in a year.
The fruiting and yield of introduced species are influenced by new environmental conditions and the rhythm of fruiting, its abundance can differ sharply from the yield under natural growth.
The period of greatest fruiting in trees falls on the middle age, after the period of rapid growth in height ends (see Appendix 3). The age of abundant fruiting is associated with the total life expectancy - in such short-lived species as willow, poplar, birch, it begins at 10 - 20 years, and in long-lived - at 30 - 50 years (for pine) and at 40 -50 years (for oak ). In shrubs, the period of abundant fruiting begins in 3-8 years. Usually abundantly fructify and give seeds of good quality specimens growing in freedom and on the sunlit side of the crown.
Fruiting depends on weather conditions: in rainy cold weather, the seeds may not ripen, the fruits may fall off, and in the heat, the seeds may die from drying out and overheating. Weather conditions during the formation of the generative organs and during the flowering period also determine what the crop will be like. Features of fruiting are also a hereditary quality.
Fruits and seeds of ornamental tree species are characterized by great morphological diversity. Fruits are single- or multi-seeded, according to the quality of the pericarp, they are divided into dry and juicy and drop-down and non-open.
Dry drop-down multi-seeded fruits have:
prefabricated leaflet (single-celled fruit) - spirea, magnolia, bladder fruit;
a box (multi-cavity fruit) - euonymus, weigela, hydrangea, willow, chestnut, parrotia, rhododendron, lilac, boxwood, poplar, mock orange;
bean (single-nested, cracking at the abdominal seams) - amorpha, albition, wisteria, honey locust, gorse, caragana, lespede-tsa, broom, robinia, sophora, chingil.
Dry non-opening fruits have:
two-seeded lionfish - maple, liriodendron;
achenes - ailanthus, birch, elm, plane tree, ash;
walnut - beech, oak, hazel, walnuts, gray, black;
nut - zelkova, hornbeam, linden, alder.
Juicy fruits have a watery pericarp containing 75-85% water in the tissues at the time of ripening. They are usually brightly colored and are represented by woody berry- and apple-shaped fruits and drupes.
Berry fruits have actinidia, elderberry, barberry, grapes, honeysuckle, shadberry, gooseberry, mahonia, currant, rose; apple-shaped - chokeberry, hawthorn, pear, cotoneaster, mountain ash, apple tree; drupe fruits - apricot, Amur velvet, privet, hawthorn, cherry, daphne, dogwood, viburnum, buckthorn, sucker, almond, olive, plum, svidina, bird cherry, pistachio.
Complex drupes include raspberries, mulberries, and dry drupes - almonds.
Fruits collected in compact formations that arose from a compact inflorescence and create the impression of a single fruit (birch catkins, raspberry and mulberry fruits, conifers) are called seedlings. So, the fruits of mulberry are a compound fruit of a complex drupe. In coniferous seedlings are cones. In juniper, the cones are called cone berries, because in appearance, with tightly fused scales, they resemble berries, more or less juicy.
Tree species are characterized not only by a large morphological variety of fruits, but also by a different internal structure of seeds (Fig. 4.5).
The variety of fruits in ornamental tree species determines the variety of methods for their collection, processing, storage and preparation of seeds for sowing.
Harvesting of fruits in most cases is carried out when the seeds are ripe. An indicator of maturation is the external morphological signs of ripening of fruits and cones: the seeds are considered ripe when the fruits are separated from the mother plant. However, in some species (spruce, pine, robinia, honey locust, sophora, cercis, ash), the seeds ripen long before the fruits and cones fall off.
The ripening of seeds and fruits is influenced by growing conditions: in the south, in a hot climate, fruits and seeds are ripe
a
in
Rice. 4.5. The structure of the seeds of various types of tree species:
a- pears, b - magnolias, in- fir; / - seed covers; 2 - cotyledons; 3 - hypocotyl; 4 - fleshy covers of the seed; 5 - hard covers of the seed; 6 -
endosperm; 7-germ
move faster; in plantations later than on individual plants. Therefore, the collection of fruits and seeds should be carried out as they ripen, at the appropriate time.
The terms of maturation and collection of seeds of the most commonly grown breeds are given in table. 4.22; the timing of seed collection is average for the region south and north of Moscow, they are average for many years, you need to focus on them, but you should definitely take into account the local climate and the weather conditions of each year.
The timing of the collection of fruits and seeds according to other authors is given in Appendix 4.
The maturation of seeds in different fruits and seedlings is determined by characteristic external signs. Most often, this is a change in the color of the fruit: in elm - yellowing of the lionfish and! light brown seeds; in fluffy birch - browning of earrings and their fragility; in caragana tree - hardening and yellowing of the beans; in pines and spruces - browning of cones: in the seedlings of linden, the leaf turns brown, and the nuts become grayish-greenish; the appearance of the first "gun" is observed in single opened poplar bolls; in an apple tree, juicy edible fruits acquire a characteristic color and taste, in oak seeds a dark brown color.
Harvesting of seeds is carried out from the moment the fruits ripen until they begin to fall, otherwise the seeds will either fall out of the fruit shell or be destroyed by animals and insects. Mature fruits in some species fall off a few days after ripening, in others - within a few weeks and even months.
At the same time, fruits and seeds ripen and fall off at weeping and fluffy birch, pedunculate and red oak, common hazel, blue honeysuckle, coverlet and edible, willow and
Flower - reproductive organ of angiosperms.
The flower is a modified shortened spore-bearing shoot of limited growth, adapted for the formation of micro- and megaspores, gametes and for pollination. As a result of pollination and the subsequent sexual process, the ovules develop into seeds.
By position, the flower is apical or lateral, i.e. emerges from the axil of the bract.
The flower is made up of
§ stem part(pedicel, receptacle) - axial organs of the flower
§ leaf part:
From vegetative leaves: sepals- green leaves petals- colored leaves
function : form a perianth that attracts pollinating insects that protect the reproductive parts of the flower
From spore-bearing leaves: pestle - consists of an ovary - the lower, expanded part of the pistil, style and stigma; stamens - consist of a stamen filament and an anther, the halves of which are called pollen sacs.
Function: reproductive parts (organs) of the flower, providing seed reproduction and fruit formation.
The part of the shoot between the flower and the bract is called pedicel. If the pedicel is shortened or absent, then the flower is called sedentary.
The upper extended part of the pedicel, to which all parts of the flower are attached, is called receptacle. The receptacle has a different shape - flat, convex, concave. Depending on the shape of the receptacle, the position of the ovary in the flower is distinguished - lower and upper. Outside on the receptacle are formed sepals, forming cup.
ü calyx called the set of sepals, and it usually differs significantly in color from the corolla. Sepals (usually green) may be free, ie. unfused, and then the calyx is called single-leaved. If the sepals grow together at certain levels, then such a cup is called joint-leaved.
ü Behind the sepals are the petals that make up whisk. The color of the corolla is varied. Just like the calyx, the corolla can consist of free(apple tree) or fused(potato, bindweed) petals.
There are simple perianth and double.
Perianth, the leaves of which are colored the same, is called simple.
The brightly colored, simple corolla-like perianth is called corolla(tulip).
The calyx and whisk are double flower perianth. These are sterile elements, i.e. they are not directly involved in the process of reproduction. The perianth performs a protective function and attracts pollinating insects.
Behind the perianth are stamens, and in the very center of the flower - one or more pistils.
ü Stamens and pistils are the reproductive elements of the flower, in which the processes associated with reproduction take place.
Neither the stamens nor the pistils are sexual organs, but they determine the sex of the flower, because. in their certain parts, male and female germ cells are formed as a result of complex processes.
ü Stamen consists of filament and anther. The anther is formed from two halves, each of which is represented by two microsporangia (pollen sacs). Microspores are formed inside the pollen sacs. In the center of the flower is one or more pistils.
ü Pestle consists of stigma, style and ovary. Lower, expanded, part of the pistil - ovary- has a cavity in which the ovule is located. The closed position of the ovule is a characteristic feature of angiosperms.
Most plants have flowers that have both stamens and pistils. it bisexual flowers. But in some plants, some flowers have only pistils - this is pistillate flowers, and others - only stamens - staminate flowers. Such flowers are called dioecious.
§ monoecious called plants in which pistillate and staminate flowers develop on the same plant (cucumbers and corn)
§ Dioecious called plants in which staminate flowers are located on some plants, and pistillate - on others (hemp, poplar, willow). At the poplar in spring, male trees are dusty - they scatter pollen, and in summer female trees scatter white fluff - flying seeds of the plant.
Plant propagation - it is the process of reproduction by organisms of new, similar individuals. For fruit and berry plants, seed (sexual) and vegetative propagation is used.
seed reproduction.
seed propagation carried out
sowing seeds resulting from the fusion of parental gametes. Reproduction by seeds is a type of reproduction common in nature and in culture, the easiest and most accessible. Under favorable conditions, seeds can be stored for many years. Sowing seeds and growing plants from them can be easily mechanized. In some crops (apple), seed propagation makes it possible to obtain healthy plants, free from the most harmful viruses, characterized by longevity, wide adaptive capabilities to environmental conditions, and forming a powerful drought-resistant root system.
Most varieties of fruit and berry crops form, as a result of cross-option, heterozygous seeds, from which plants grow that differ in genotype and phenotype from the parental individuals, which start fruiting late. Therefore, seed propagation in fruit growing is mainly used in breeding work when breeding new varieties and when obtaining rootstocks.
Vegetative (parts of a plant) reproduction.
Vegetative reproduction is the process of reproduction of new plants from separated or non-separated vegetative parts of the mother plant (Fig. 3). Vegetative reproduction is carried out with the participation of only somatic cells, tissues and organs of the parent (mother) plant. The basis of vegetative propagation is regeneration - the ability of plants to restore lost organs and tissues. Vegetative propagation is the main method of growing bedbug rootstocks and varieties of fruit and berry crops. During vegetative propagation, economically valuable traits of propagated varieties are preserved, plants begin to bear fruit early and produce homogeneous offspring. Disadvantages of vegetative propagation of plants: the possibility of transmitting a viral infection to offspring, the formation of a weak root system and less longevity of trees.
Depending on the method of vegetative propagation, own-rooted and grafted plants are distinguished. In self-rooted plants, all tissues and organs are composed of cells with the same genetic inheritance. Seed plants (seedlings) are also self-rooted, but they are obtained on the basis of seed propagation. In grafted plants, the aboveground part belongs to the scion - usually a cultivated variety, and the root system (sometimes part of the aboveground system) - to the rootstock, which differ in genotype. Methods of vegetative propagation of fruit and berry plants can be divided into natural and artificial.
Natural methods include rooting with rosettes of leaves on the mustache, propagation by rooting the apical bud of hanging branches, root offspring, root shoots and dividing the bush (particulation).
mustache called modified shoots, in the nodes of which rosettes of leaves are formed. When in contact with the soil, roots form on the outlet and thus a new plant is obtained. In this way, strawberries and strawberries are propagated in the nursery.
In a blackberry, at the top of an arcuate shoot, when in contact with the ground, a bud is formed, on which adventitious roots appear, quickly deepening into the soil, and a shoot, as a result of which a new plant is formed.
Root offspring are formed as a result of the germination of adnexal buds on the horizontal rhizomes of raspberries. By the end of the growing season, roots appear in the lower part of such shoots, the offspring are separated from the mother plant. Some forms of cherries and plums are propagated by root shoots. Hazelnuts and chokeberries have shoots of stem origin.
Berry crops are propagated by dividing the bush.
Artificial methods include propagation by cuttings, layering, grafting and meristem cells (clonal micropropagation, or tissue culture).
Propagation by cuttings.
cutting called the part of the stem or root, separated from the mother plant. Getting a new plant from a cutting is based on regeneration and polarity, when roots are formed at the morphologically lower end of the cutting, and stems are formed at the upper end.
Rice. 3. Ways of vegetative propagation of fruit and berry plants:
a - arcuate layering; b - sockets; in - vertical layers; G - root
offspring; d - horizontal layers; e - lignified cuttings; and - green
cuttings; h- root cuttings; and - clonal micropropagation
In fruit growing, reproduction is used by stem lignified, stem non-lignified (green) and root cuttings.
Lignified stem cuttings propagate currants, bedbug rootstocks, pomegranate, figs, sea buckthorn, olives and other crops, green (leafy) cuttings - currants, gooseberries, lemons, clonal rootstocks, sea buckthorn, etc. Green cuttings take root better than lignified ones. Root cuttings are promising to propagate raspberries, cherries, clonal stocks, plums, cherry plums. However, due to the difficulty of harvesting cuttings, this method is rarely used.
Clonal micropropagation should be considered as a particular method of cuttings, when growth points (apexes) of growing shoots, which are microcuttings, are used for propagation. Reproduction is carried out under sterile conditions on nutrient media to obtain and multiply virus-free planting material.
Reproduction by layering.
layering called the branches rooted on the mother plant. Reproduction by layering is based on the ability of growing shoots to form adventitious roots. Reproduction is distinguished by vertical, horizontal, arcuate and air layering.
Vertical layering is the main method of propagation of clone-new rootstocks of apple and pear, berry crops. Bed bug rootstocks and currants are propagated by horizontal layering.
Arcuate layers are used to propagate hard-to-root crops (hazel). The branch of the mother plant is bent in an arcuate manner, covered with soil and one strong layer is obtained.
Due to the difficulty and low yield of planting material, air layers are not used in nurseries of fruit and berry crops.
a - inoculated seed stock: / - cultivar shield; 2 - shield of bug rootstock; b - view of the oculant in a year: 3 - annual cultivar; 4 - rooted cuttings of bedbug rootstock
Reproduction by grafting.
Inoculation called the connection of parts of plants for fusion and the formation of a single organism with new properties.
There are grafting with an eye (budding), cutting and rapprochement (ablactation). Budding is the most common way to propagate woody fruit crops in a nursery (Figure 4). It is simple to perform, provides good fusion of grafted components, high yield of seedlings.
Grafting by cuttings is used less frequently: in the nursery - during winter grafting, in the garden - to improve the assortment, in the treatment of trees, etc. This method of grafting is more laborious and the cuttings take root worse. Ablactation is rarely used in breeding and in the treatment of damaged trees, while the grafted components are on their roots until they grow together.
A strong fusion of a scion with a rootstock and further normal growth and development of a grafted plant is called compatibility. The main condition for the successful fusion of a rootstock with a scion is their botanical relationship. Various signs of oppression of grafted plants, often leading to death, are called incompatibility. This phenomenon is observed when grafting, for example, European varieties of pear on the Ussuri pear, cultivars of apple trees on the Siberian apple tree. The reasons for the incompatibility of rootstock and scion have not yet been fully elucidated. The biological essence of incompatibility lies in the violation of the metabolism between the aerial part and the roots. Empirically, well-compatible combinations are selected, which are later used in growing seedlings.
In the process of vital activity of grafted plants, the stock and scion have a mutual influence. The rootstock affects the strength of growth, longevity, early maturity, yield, fruit quality and resistance to adverse environmental conditions of the grafted tree. For example, on dwarf rootstocks, grafted varieties bear fruit early, have better quality fruits, and are less durable than varieties grafted on vigorous rootstocks. The winter hardiness, drought resistance and salt tolerance of grafted trees, the strength of their fixation in the soil, the resistance of roots to pests and diseases, etc., largely depend on the stock. Changes in the scion and rootstock in the process of mutual influence are not hereditary and are not saved when creating a new scion-rootstock combination.
When growing plants in rooms, the seed method is used quite rarely, since it is quite complicated and requires stricter adherence to temperature and humidity. During seed propagation, varietal and other characteristics are not always transmitted, for example, terryness, variegation. The disadvantage of seed propagation is also a later flowering. However, it makes it possible to obtain new varieties. Few plants propagate by seeds (cacti, palm trees, laurel, coffee, etc.). Seeds for propagation must be collected from healthy plants with beautiful flowers that have all the qualities that you would like to have in future grown crops. Fruits with seeds are harvested after they ripen in a warm and dry season and placed in a cloth or paper bag. After a few days, the seeds are removed from the fruit and stored in a paper bag in a cool, dry place (you can in the refrigerator). Some seeds? species of tropical plants require high temperatures for germination, which are much higher than room temperatures; therefore, for crops, you need to have a small greenhouse with bottom heating (up to 30 ° C). Sowing is usually carried out in the spring. However, some seeds plant species (laurel, palm trees, anthuriums, etc.) should be sown immediately after harvest, as they quickly lose their germination capacity. Seeds with poor germination (mostly coniferous plants) must be sown immediately after they are collected. To make sure that the seeds are suitable for sowing, they must be lowered into a glass of water. Seeds that have lost the ability to germinate will remain on the surface of the water, and able to germinate will sink to the bottom. Before sowing, seeds with a hard shell, such as those of palms and acacias, are lightly filed to ensure access of water and air to the embryo and accelerate germination. Some seeds? subtropical plants (camellia, feijoa, tea) need stratification. They are placed in a pot with wet sand, everything is wrapped in plastic wrap and stored in a refrigerator at a temperature of 6--8 ° C for about 2 months, moistening periodically. In the rooms you can grow amaryllis, tuberous begonia, balsam, primrose, clivia, cyclamen, cineraria, gloxinia, coffee tree, pelargonium, ruellia, etc. All of these species in the conditions of central Russia give good seeds. Seeds are sown in small pots, bowls and wooden boxes with drainage holes. Each hole is covered with a shard, and in pots drainage is made at least 1-2 cm high from shards, pebbles or coals. This layer prevents drain holes from being clogged with earth and thus helps to remove excess moisture. The dishes are filled with an earthen mixture (2 parts of leafy soil, 1 part of light turf and 1/2 part of river sand), the surface is well leveled and sowing begins. The earth should be without coarse lumps, but it is not recommended to sift it through fine sieves, as in this case it quickly turns sour. It is easiest to sow large seeds: they are not too densely placed at equal distances from each other. Hard-skinned before sowing, put for 4-6 days in warm water, the skin swells and the appearance of sprouts is facilitated.
After sowing, seeds of medium size are covered with a layer of earth, the thickness of which is equal to or slightly greater than the thickness of the seed. Then the ground is leveled with a smooth board. The heavier the earth, the thinner the coating layer should be. If the coating is too thin, the root lifts the seed and pushes it out of the ground, as a result of which the young plant may die. The sown seeds are covered with peat soil sifted through a fine mesh. It is porous, loose and provides gentle seedlings with stable moisture. Large seeds can be immersed in the ground by 2-4 cm (palms, laurel, etc.). Small ones (begonia, gloxinia, peperomia, mamillaria, etc.) are usually not covered with earth, since when watering they themselves go deep enough into the soil.
For some? seeds, such as tuberous begonias, the ground must first be calcined to eliminate the development of mold and moss, which prevent the normal development of young shoots. Large seeds covered with earth are watered from a watering can with a fine sieve, small seeds that are not covered - with great care using a spray bottle (it is better to pour water into pallets). Crops are covered with glass and maintain uniform humidity. Containers with sown seeds are placed in a warm place in the shade, where the temperature changes little. You can replace the glass with a layer of wet moss, which will keep crops well aerated (air access). It is necessary to monitor the germination of seeds in order to raise the moss (or remove the glass) in time to avoid stretching the seedlings. In the spring, the pots are placed in a place far from the light in order to retain moisture. If the soil is too dry, seedlings do not develop, if it is too wet, they begin to rot. Sprouts are watered with a watering can with a fine strainer, and it is best to immerse the pot in a container of water, but at the same time make sure that the water level in it is 2 cm lower than the upper edge of the pot. This method of watering will thoroughly soak the entire earthen ball and is beneficial in that sprouts avoid mechanical action of water.
The seeds of most species contain a supply of nutrients and other substances; therefore, in the first days of growth, the seedling does not need nutrients from the external environment. But in general, for normal development, a plant needs water, air access, and the right temperature. The temperature at which the seeds of various plants successfully germinate is closely related to the geographical distribution of this species. Seeds of palms and other representatives of the tropics germinate at 22-26°C. Seeds that germinate for a long time and are difficult should be sown in January and February, the rest in March and April. Too late sowing is not recommended, as in this case the seedlings do not have time to develop sufficiently before the onset of autumn.
Most houseplants germinate in 2-3 weeks, some? - in a few days, in palm trees - in a few months. With the advent of seedlings, the glass cover is removed and the tender plants are gradually accustomed to light. The temperature after seed germination is reduced by 3--5°C to prevent young seedlings from stretching. Larger seedlings can be planted in pots 7x7 cm, and small seedlings can be planted (seated) at a distance depending on the size and speed of development of this plant. Small seedlings, such as begonias and gloxinia, need to dive several times until they develop, then plant one by one in pots. Small seedlings are planted with a pick peg and tweezers.
Shortening (pinching) the roots of seedlings somewhat delays their growth, but over time, the roots grow into a branched, fibrous root system, which ensures excellent development of the aerial parts of plants and their abundant flowering.