Technology of proper planting and care for ornamental plants

Planting in open ground: timing, density, and depth

Successful cultivation of ornamental crops in open ground, greenhouses, or containers depends on adhering to planting rules. It is important for an agronomist to accurately calculate the timing, planting depth, and plant spacing. These parameters are directly determined by the biological characteristics of a specific crop. Errors at this stage lead to delayed development, lack of flowering, or the death of planting material.

Flowering plants are planted before the development of flower buds or after they have set, so as not to disturb the flower formation process. In open ground, the timing of work is tied to the cold hardiness of the crops. In spring, transplants of cold-hardy annuals are moved to flower beds first. Thermophilic species are planted later, once the threat of late frosts has completely passed. Less winter-hardy perennials, such as cultivar roses, are planted only in spring so they have time to reliably root before winter.

The planting density of plants per square meter determines the development of their above-ground part. The distance between bushes during planting is calculated as half of their normal habitus during the flowering period. When calculating the spacing, the compactness of the cultivar and the planned duration of cultivation in one place are taken into account. Violation of density norms leads to the following problems:

• Dense planting leads to etiolation and weakening of plants due to a lack of light, moisture, and nutrients.
• Sparse planting provokes active weed growth and reduces the overall aesthetic appeal of compositions.

Planting depth depends on the structure of the underground organs (bulbs, rhizomes, corms) and the mechanical composition of the soil. In light soils, plants are placed deeper than in heavy ones. Violation of this rule directly affects the crop's ability to flower.

Soil type	Peony bud placement depth
Heavy soils	No more than 5 cm
Light soils	No more than 7.5 cm

When planting, it is important to keep the root system healthy. Do not allow roots to bend, twist, or compress, and prevent the formation of air pockets around them. Carry out planting work in the morning, evening hours, or in overcast weather to protect plants from wilting and sunburn.

1. Cover the roots with soil, slightly press and firm the soil to eliminate air pockets around the root system.
2. Level the soil surface around the planted plant.
3. Water the plantings abundantly for better contact between roots and soil.

Cultivation of potted crops and transplanting rules

Houseplants and container plants require regular transplanting to renew depleted substrate. The procedure is performed when signs of a lack of free space or soil degradation appear. Signals for urgent transplanting include rapid drying of the root ball, slowed growth, and the appearance of a musty odor. Work also begins if the roots have completely intertwined the soil and emerged through the drainage holes.

Scheduled transplanting of potted crops is carried out from February to May. Species that bloom in the spring are moved to new containers only after flowering is complete. Unscheduled transplanting is done if the root system is damaged. The procedure is also combined with the division of overgrown bushes (asparagus, aspidistra, clivia) or the separation of daughter bulbs (hippeastrum, crinum, eucharis).

The new pot should exceed the old one in diameter by no more than 3–4 cm. This allows the roots to quickly occupy the fresh soil and reduces the risk of soil acidification due to waterlogging. Pots, cachepots, and containers are used for this work. Pots with a diameter of 3 to 30 cm must have drainage holes.

• Clay pots are made of porous material, which contributes to the evaporation of excess moisture and the leaching of harmful salts from the soil.
• Plastic pots are lightweight and durable; they lose moisture more slowly but require the use of a maximally loose and permeable substrate.
• Cachepots are containers with a solid waterproof bottom, inside which a working pot is placed.
• Containers are solid waterproof vessels for growing a group of plants or placing several pots, requiring extremely careful irrigation.

Before use, used flower pots must be disinfected. First, the containers are thoroughly washed of soil residues and salts. Then they are completely immersed in a disinfecting solution for 30 minutes.

Disinfectant	Solution concentration
Formalin	2%
Copper sulfate	3%
Potassium permanganate	According to instructions

• Planting depth of peony in heavy soil — no more than 5 cm
• Planting depth of peony in light soil — no more than 7.5 cm
• Increase in the diameter of a new pot — no more than 3–4 cm
• Disinfection time for containers — 30 minutes

Technology of Transplanting and Repotting of Potted Crops

Proper transplanting and repotting of potted crops is the key to their quick establishment and healthy development. When transplanting it is important to handle the root system with care, prepare the planting container, and ensure the drainage of excess moisture. To do this, drainage materials are placed at the bottom: expanded clay, coarse sand, pebbles, or broken pottery shards.

• Thickness of the drainage layer — 2–3 cm
• Layer of soil over the roots — 1.5–2 cm
• Watering clearance (headroom) — 1.5 cm
• Quarantine in a hotbed — 1–2 weeks
• Frequency of repotting for young crops — annually

Follow the sequence of technological operations to minimize plant stress:

1. Water the plant abundantly one day before transplanting.
2. Turn the pot upside down while holding the soil ball with your hand, and carefully remove it by gently tapping the edge of the container against a table.
3. Remove drainage from the bottom of the ball, completely or partially clean the roots from old soil, and for diseased plants, gently wash them.
4. Inspect the roots, shorten overly long ones, cut out rotten areas, and be sure to dust the cuts with crushed charcoal.
5. Place a shard at the bottom of the new pot over the hole, convex side up, for drainage of excess moisture and add the drainage material.
6. Add the soil mixture, place the plant strictly in the center of the pot, gradually add soil, and firm it with a wooden dibber.

The drainage layer is increased if the plant has a weak root system, the pot is too deep, or it lacks drainage holes. After planting, plants are sprayed, watered with warm water, and protected from direct sunlight.

Repotting (transferring) allows moving a plant to a larger diameter pot without disturbing the soil ball. This method increases the nutrient area, improves growth and, unlike transplanting, does not delay flowering. Young plants are repotted annually, large and slow-growing ones — every 2–5 years, and large tub crops — only when the tub is damaged or severely cramped.

Agricultural Care: Weed Control, Loosening, Mulching, and Top Dressing

Weeds cause serious damage to flowering crops, especially to seedlings and transplants. They compete for moisture, light, and nutrients, and also serve as a source of diseases and pests. Mechanical weeding or herbicides are used to control them.

Mechanical weeding is one of the most labor-intensive processes in floriculture. It is carried out by hand or with cultivators throughout the entire growing season:

• before the plants close canopy in the open ground — 3 times;
• in total per growing season — at least 4–5 times.

In large-scale operations, herbicides such as atrazine, simazine, and Roundup are used to control weeds in fallow fields and large areas of perennials. Systemic preparations are distributed throughout the weed, causing its total poisoning. This significantly increases labor productivity compared to manual weeding.

Timing of herbicide application	Purpose of application
Autumn (after harvesting flower crops)	Destruction of germinating seeds and weed rhizomes
Spring (a month before sowing or planting)	Preparation of the site for growing crops

In small areas, the soil is loosened with hand hoes and cultivators, and in large operations — with tractor-mounted cultivators. The first loosening is carried out immediately after the plants are securely established. When growing on hydroponics with low-moisture substrates, loosening and weeding are not required.

Mulching helps conserve moisture, smooth out daily soil temperature fluctuations, and stop weed growth. For this, the soil is covered with mulch paper, perforated film, or organic matter — manure, humus, peat, straw, sawdust in a layer of 3–5 cm. Organic mulch additionally enriches the soil with nutrients; however, mulching is not performed if the groundwater level is high.

Timely nutrition ensures abundant flowering and healthy growth of flowering crops. In open ground, 3–4 top dressings are applied during the growing season, with the last one strictly before mid-August. In greenhouses, fertilizers are applied every 10–14 days during the active growth phase. Young plants are fertilized only after secure establishment, and as they enter the dormant state, fertilizer application is gradually stopped.

Bush formation and care of the aerial part

The growth direction and density of shoots of ornamental crops can be regulated artificially. In practice, pruning, pinching, disbudding, and shearing are used for this purpose. These technological techniques help to redistribute the flow of nutrients and improve the commercial appearance of the plants.

Pruning stimulates branching, rejuvenates perennials, and helps to form a compact canopy. When performing it, the vigor, condition, and growth direction of each specific shoot are always taken into account. During transplanting, root pruning is also performed, removing old and damaged sections and shortening excessively long taproots.

Pinching consists of removing the apical bud or the leafy end of a shoot 1.5–2 cm long. After this, the linear growth of the stem stops, and nutrition is redirected to lateral shoots for their accelerated development. The method is essential for enhancing the branching of balsam and snapdragon, as well as for regulating the flowering time of chrysanthemum and greenhouse carnation. In addition, pinching is used to control overgrown transplants.

Disbudding consists of removing weak lateral shoots or extra buds. The technique allows for larger flowers in peonies, large-flowered carnations, and tall cultivars of dahlias and chrysanthemums. It is necessary to remove lateral buds at the earliest possible phase; furthermore, the closer the shoot is to the main bud, the earlier it is removed.

Pruning and disbudding are also the basis for growing standard forms of rose, myrtle, and fuchsia. Systematic removal of faded buds and inflorescences maintains decorative appeal and stimulates a secondary wave of flowering, for example in snapdragons. Shearing, unlike pruning, involves uniform shortening of most shoots to give plantings the desired height and density. It is regularly carried out in flower beds on ornamental foliage bedding plants, such as alternanthera and iresine. To protect the aerial part of the plants, pest and disease control is also organized, and the leaves of potted crops are regularly washed and sprayed.

Use of growth regulators in cutting propagation

Growth regulators allow for the targeted stimulation or suppression of plant vital processes. In agronomy, both natural phytohormones and their chemical analogs are used. Natural stimulants include auxins (indoleacetic acid and its derivatives) and gibberellins (gibberellic acid).

Synthetic growth regulators are classified into groups:

• Auxins: heteroauxin (potassium salt of indoleacetic acid, K-β-IAA), α-naphthylacetic acid (α-NAA), β-indolebutyric acid (β-IBA);
• Gibberellins: gibbersib;
• Cytokinins: kinetin, 6-benzylaminopurine (6-BAP).

Auxins activate cell division, accelerate seed germination, stimulate root formation in cuttings, and help to overcome the dormancy period. Heteroauxin, β-indolebutyric and α-naphthylacetic acids, as well as Kornevin, are widely used in the vegetative propagation of carnation, rose, and chrysanthemum. The effectiveness of auxins increases noticeably if they are used in combination with vitamins C and B1.

1. Prepare an alcoholic or hot aqueous concentrate of the preparation, since auxins are practically insoluble in cold water. To do this, dissolve a weighed portion of the substance in a small amount of 96% alcohol or hot water.
2. Dilute the resulting concentrate with cold water until the required application rate is reached.
3. Soak the cuttings in the working solution for the time established by the regulations.

Type of cuttings	Preparation / Active ingredient	Concentration, mg/l	Exposure time, h
Herbaceous stem and root	Heteroauxin	50–70	8
	Indolebutyric acid	25	6–8
	Naphthylacetic acid	20	5–7
	Vitamin C	500	—
	Vitamin B1	50	—
Green stem and leaf	Heteroauxin	200	12
	Indolebutyric acid	50	8–12
	Naphthylacetic acid	30	8–10
	Vitamin C	1000–2000	—
	Vitamin B1	200	—

• Pinching depth of a shoot — 1.5–2 cm
• Temperature of the stimulant solution — 18–20 °C
• Minimum processing temperature — 15 °C
• Shelf life of working solutions — up to 7 days

Growth stimulants: recipes for rooting and phases of gibberellin application

For the cutting propagation of crops sensitive to excess moisture, classic soaking in water is not suitable. In such cases, agronomists use alcoholic solutions, dry growth powders, or lanolin pastes. They ensure rapid contact of the active ingredient with plant tissues without the risk of rotting.

Alcoholic solutions are prepared on the basis of 50% ethyl alcohol. Add either 10 mg of heteroauxin, 10 mg of indolebutyric acid (IBA), or 6 mg of naphthylacetic acid (NAA) per 1 ml of alcohol. The processing time for cuttings in such a solution is strictly limited.

Technology for preparing growth powder

1. Dissolve an aliquot of the growth regulator (30 mg of heteroauxin, IBA, or NAA), 100 mg of vitamin C, and 10 mg of vitamin B1 in a small volume of hot water.
2. Thoroughly mix the resulting solution with 1 g of a base—talc or crushed charcoal.
3. Dry the finished mixture in a dark place at a temperature of 50–70 °C.
4. Moisten the lower ends of the cuttings with clean water, dip them into the resulting powder, and immediately transfer them into the substrate for rooting.

Technology for preparing growth paste

1. Heat lanolin (animal wax) in a water bath until it reaches a liquid state.
2. Dissolve an aliquot of the stimulant in 20–30 ml of alcohol and mix thoroughly with the liquid lanolin.
3. Cool the mixture to room temperature (the finished paste can be stored in the refrigerator in a closed container for several years).
4. Apply the paste to the lower cut and the adjacent part of the cutting, then immediately plant it in the substrate.

To activate growth processes and improve the commercial quality of flowers, gibberellins (in particular, A3) are used. They stimulate shoot elongation and increase the size of inflorescences, double-flowering, and the color intensity of buds in carnations, hydrangeas, petunias, roses, salvias, phlox, chrysanthemums, cinerarias, and other crops. When treating bulbs and corms, these preparations accelerate flowering and increase the yield of offsets.

Preparation parameter	Recommended working concentration
Concentration of aqueous solutions of gibberellin A3	0.0001–0.0050%

"Gibbersib" is a mixture of gibberellic acids obtained from a microbiological culture of fungi of the genus Fusarium. It is applied by spraying plants with weak aqueous solutions during different growth periods, depending on the desired result. Methods of application include placing drops of the suspension on buds and inflorescences, as well as soaking bulbs and seed.

Cytokinins stimulate cell division, seed germination, and bud initiation. In commercial floriculture, they are indispensable for clonal micropropagation (in vitro). These substances activate cell division and tissue differentiation, which induces active shoot formation.

Inhibitors and retardants: managing height and flowering dates

Controlling growth rates is no less important than stimulation. To prevent plants from becoming etiolated and to regulate their life cycle, natural inhibitors and synthetic preparations are used. In practical floriculture, they allow for the control of crop height and their flowering times.

Among natural inhibitors, abscisic acid (ABA) and ethylene play a key role. ABA works even in minimal concentrations: it reduces transpiration to conserve moisture, inhibits seed germination, and halts maturation. This acid also inhibits the synthesis of enzymes required for photosynthesis and causes leaf abscission.

Ethylene is a gaseous substance that inhibits seedling growth, causes leaf petiole curvature, and neutralizes the action of stimulants. In the confined space of warehouses, the accumulation of this gas leads to the rapid wilting of cut flowers. To protect the produce, storage in special airtight bags is practiced.

Synthetic growth limiters are divided into several groups depending on their effect on plant physiology. Antiauxins inhibit the transport of natural auxin (indole-3-acetic acid) through tissues, while morphactins disrupt morphogenesis at growth points. Paralyzers sharply stop the growth of all organs, whereas retardants suppress stem development and accelerate flowering.

In practical floriculture, retardants are used to create a compact habit and prevent the overgrowth of transplants, forced crops, and potted plants. They block the activity of gibberellins, which restrains shoot elongation without reducing leaf area. Under their influence, internodes are shortened, stems become stronger, leaves accumulate more chlorophyll, and flowers grow larger. Retardants also stimulate the development of the root system, bulbs, and tubers.

To control height and improve plant quality, the following retardants are used:

• CCC (chlormequat chloride, active ingredient — 2-chloroethyltrimethylammonium chloride; domestic analogues — TUR and ZAR);
• Alar (daminozide, also known as B9 or SADH);
• Ethrel (chloroethylphosphonic acid, or ethephon);
• Phosfon (tributyl(2,4-dichlorobenzyl)phosphonium chloride, or chlorphonium);
• Atrinal (sodium salt of 2,3:4,6-bis-(1-methylethylidene)-α-L-xylo-2-hexulofuranosonic acid, or dikegulac).

• Exposure time for alcohol solution treatment — 15 h
• Drying temperature for growth powder — 50–70 °C
• Soaking time in "Gibbersib" suspension — 4–12 h
• Oxygen content in cut flower storage environment — up to 4%
• Carbon dioxide content in cut flower storage environment — up to 5%

Application of humates, biological products, and anti-stress growth regulators

Physiologically active substances help ornamental crops adapt to adverse conditions and optimize mineral nutrition in open soil and greenhouses. In modern floriculture, humic preparations, specialized biological products, and natural growth regulators are used for this purpose. These substances activate soil microflora, improve nutrient uptake, and protect plantings from climatic and chemical stresses.

• Concentration of retardant solutions — 50–200 mg/l
• Humic acids in "Sodium Humate" — no less than 70%
• Humic acids in "Peat Oxidate" — 68%

Humic substances perform accumulation, transport, regulatory, and protective functions. "Sodium Humate" is used for spraying plants, as well as for pre-planting treatment of seed and cuttings. This improves the morphological characteristics of crops and reduces the toxic effect of industrial pollution on petunia, salvia, balsam, callistephus, and antirrhinum.

"Peat Oxidate" serves as an effective synergist when applied together with other agrochemicals. It enhances the effect of plant protection products and mineral fertilizers, which allows for a significant reduction in their application rates when preparing tank mixtures. The preparation also helps ornamental crops tolerate drought, recurring frosts, lack of moisture, excessive soil salinity, and the accumulation of pesticides.

Type of concomitant preparation	Reduction in application rate when used in combination with "Peat Oxidate"
Pesticides	30%
Mineral fertilizers	20–25%

Specialized biological products are used for the targeted stimulation of physiological processes. These include APS (seed germination activator), APM (soil microflora activator), and AF (plant photosynthesis activator). The natural bioregulator "Epin," based on epibrassinolide, which manages plant growth and development at key stages of the growing season, also shows high efficiency.

"Epin" is used to solve the following practical tasks:

• acceleration of tulip bulb and gladiolus corm germination;
• increase in the number of buds and inflorescences in helenium and phlox;
• stimulation of root formation in gerbera, rose, and chrysanthemum cuttings;
• increase in the resistance of floral crops to adverse environmental factors.