The rose is beautiful and, without any doubt, is the "queen of flowers". By correctly planting roses and taking the necessary care of them, you can enjoy the beauty of your rose garden for many, many years.

just need to learn how to follow some simple rules for the cultivation of a beautiful culture. Learn the basics rule : planting, feeding, watering, pruning, covering. 




1. Origin 


The rose was considered a symbol of beauty among the Babylonians, Syrians, Egyptians, Romans and Greeks. Approximately 200 botanical rose species are native to the Northern Hemisphere, although the actual number is unknown due to the existence of hybrid populations in the wild.


The first cultivated roses were in summer bloom, until further breeding in the east over some species, mainly Rosa gigantea and R. chinensis, led to the appearance of the "tea rose" of the remontant type. This rose was introduced to the West in 1793, which served as the basis for numerous hybrids that were subsequently created.


2.  Taxonomy and morphology 

The rose belongs to the Rosaceae family, and has the scientific name Rosa sp.


Currently, commercial rose varieties are hybrids of extinct rose species. For cutting, types of hybrid tea roses and, to a lesser extent, floribunda are used. The former are represented by long stems and attractive flowers, arranged individually or with some medium to large lateral buds and numerous petals that form a visible central cone.


Floribunda roses are flowers in inflorescences, some of which can be opened at the same time. The color of flowers is in a wide range: red, white, pink, yellow, lavender, etc., with different nuances and shades. They are located on spiny and upright stems.


3 Economic significance and geographical  


Among flowers, roses rank first in the world in terms of sales, followed by chrysanthemums, tulips third, carnations fourth and lilies fifth. No other decorative flower was as expensive as a rose. Since the 90s, its leadership has been achieved mainly due to the improvement of varieties, the expansion of supply throughout the year and the growing demand.

Its main consumer markets are Europe, where Germany is the leader, the United States and Japan.

It is a highly specialized crop that covers 1,000 hectares of greenhouses in Italy, 920 hectares in the Netherlands, 540 hectares in France, 250 hectares in Spain, 220 hectares in Israel and 200 hectares in Germany.

In recent years, South American countries have increased their production, especially Mexico, Colombia (about 1000 ha) and Ecuador.

Production also takes place in East Africa: 200 hectares in Zimbabwe and 175 hectares in Kenya.

In Japan, Asia's first consumer market, the rose-growing area is growing and India is currently growing 100 hectares.


4.How to grow rose  plant material 

Rose PLANT MATERIAL


The essential qualities of cut roses, in accordance with the tastes and requirements of the market at all times, are:

The stem is long and hard: 50-70 cm, depending on the growing areas.

Shiny green foliage.

Flowers: slow opening, well kept in a vase.

Good flowering (= yield per foot or per m2).

Good disease resistance.

Can be grown at lower temperatures in winter.

Suitable for soilless cultivation.

Classification of the main varieties:

Large-flowered roses (80% of production).


Reds (40-60% demand): First Red, Dallas, Royal Red, Grand Gala, Koba, Red Velvet ...

Pink (20-40% of demand): Anna, Noblesse, Vivaldi, Sonia, Omega, Versilia ...

Yellow (demand growth): Golden Times, Texas, Starlite, Live, Coktail 80 ...

Orange (demand growth): Pareo ...

Whites: Virginia, Tineke, Ariana ...

Bicolor: Candia, Simona, Prophyta, La Minuette ...

Multi-flowered roses (spray): Mini (different colors), Golden Mini, Lidia (pink), Nikita (pink).


5. How to replant a rose stem

How to replant a rose stem


Propagation can be done by seed, stem cuttings, grafting by cuttings or eyes, although the latter is the method most used commercially.

Seed propagation is used in the development of new varieties.

Cuttings are taken from flower shoots that have completed the full development of the flower to ensure that the shoot producing the flower is true. In addition, shoots without flowers are less vigorous, so they have less space for rooting.

Depending on the availability of plant material, cuttings with 1, 2 or 3 eyes can be used, although three buds are preferred as they are longer and have more nodular tissue at the base, which reduces loss caused by disease.

The base of the cuttings is immersed in the rooting hormone compound before being placed on a propagation rack with vermiculite or similar substrate with a spacing of 2.5-4 cm between plants and 7.5 cm between rows.


The appropriate humidity and temperature in the substrate must be maintained at 18-21ºC. Under these conditions, rooting occurs in 5-6 weeks, depending on the season and the type of shoot. Subsequently, they move on to transplanting in 7.5 cm pots or directly to the greenhouse.

The problem with this system is that the plants with their roots are quite small and take a significant amount of time to grow long enough to harvest flowers.

Cutting or English grafting is rarely used for commercial production of cut flowers because it also takes too long.

For peephole grafting, the most common stock is Rosa manetti and sometimes R. odorata. R. multiflora inermis is used in New Zealand and in colder areas such as the Netherlands, R. canina.

The rootstock material is obtained from plants that have been heat treated to eliminate viruses and other diseases. At the end of September, long shoots of standard rootstock plants are cut, thorns are removed and immersed in sodium hypochlorite solution (1/3 1%) for 15 minutes. They are cut into segments of 20-21 cm, I remove all the lower eyes on the cuttings, leaving three at the upper end. After soil treatment or disinfection, fertilization is carried out based on soil analysis. 

Stems treated with rooting hormones are planted from mid-November to mid-December at a distance of 122 cm between rows and 13 cm in a row, irrigating immediately after planting. The grafting is usually done in mid-June when there are enough roots and the bark can be easily detached. A "T" cut is made to the depth of the cambium under the rootstock buds. A bud from the shoot of the selected variety is inserted into the T-shaped incision, securing the graft site above and below the bud. 

After 3-4 weeks, approximately 1/3 of the rootstock is cut off above the graft, and the rest is removed 3 weeks after the seedling is dug out of the soil. Plants are cleaned and classified according to their quality (root development, plant growth, etc.), packed and stored cold (0-2ºC) until they are delivered to growers between January and June.

In the Netherlands, an alternative method known as 'stenting' is used, which involves grafting a cuttings of the desired variety onto a stock cuttings which are rooted using conventional methods. Nowadays it is also possible to produce roses in vitro.


6. What climate is best for roses?

What climate is best for roses?


6.1. Temperature


For most varieties grown, the optimum temperature for growth is between 17ºC and 25ºC, with a minimum of 15ºC at night and a maximum of 28ºC during the day. Lower or higher values ​​can be maintained for relatively short periods without serious damage, but night temperatures consistently below 15 ° C slow down plant growth, leading to the formation of flowers with a lot of petals and deforming when opened.

 Excessively high temperatures also wreak havoc on production, producing smaller-than-normal flowers with few petals and a warmer color.


6.2. Lighting


The growth rate of most rose varieties follows the overall sunlight curve throughout the year. Thus, in the summer months, when high light intensities and long days prevail, the production of flowers is higher than in the winter months.

A widespread practice in the Netherlands is to illuminate for 16 hours with illumination levels up to 3000 lux (sodium lamps) as this improves winter production in quality and quantity.

However, even though it is a long day plant, shading or darkening is necessary during the summer and even spring and fall, depending on the climatology of the site, since high light intensities are accompanied by intense heating. The first application of dimming should be light so that the change in light intensity is progressive.

It has been proven that in areas with cloudy and snowy days in winter, artificial lighting of roses can be beneficial due to increased production, although economic aspects should always be studied to determine profitability.


6.3. Ventilation and CO2 enrichment


In many areas, temperatures during the early hours of the day are too low for ventilation, yet CO2 levels limit plant growth. In winter conditions in cold climates where daytime ventilation is not economically viable, it is necessary to provide CO2 for optimal plant growth, increasing the level to 1000 ppm.

 Likewise, if the ventilation is closed before sunset, due to a drop in temperature, carbon dioxide levels continue to decline due to the photosynthetic activity of the plants.

On the other hand, it must be borne in mind that roses require relatively high humidity, which is controlled by ventilation and fog or wet aisles during the hottest hours of the day.

Aeration must be regulated manually or automatically by opening the sides and roof, sometimes supported by internal fans or even extractors (pressure or overpressure). Thus, the hygrometric level is reduced and certain diseases are controlled.


7. Rose cultivation in greenhouse 

Rose cultivation in greenhouse


By growing roses in a greenhouse, it is possible to produce flowers at times and locations where otherwise would not be possible, while getting the best prices.

 To do this, these greenhouses must meet minimum conditions: large (50 x 20 or more), sufficient light transmission, high heights, and good ventilation during hot months. In addition, heating in the winter is recommended, as well as the installation of thermal blankets to keep warm at night.


7.1. Soil preparation


To grow roses, the soil must be well drained and well aerated to avoid flooding, so soils that do not meet these conditions must be improved in this regard by using various organic materials.

Roses are tolerant of acidic soil, although the pH should remain around 6. They cannot tolerate high levels of calcium, due to the excess of this element, chlorosis develops rapidly. Also, high levels of soluble salts are not recommended, no more than 0.15%.

Soil disinfection can be carried out using heat or other treatment that meets the requirements of the crop. In the case of basic fertilization, a previous soil analysis is required.


7.2 Landing


The planting season lasts from November to March. Planting should be done as soon as possible to avoid drying out of plants that are cut 20 cm; then it is necessary to water abundantly (100 l of water / m2), keeping the inoculation point at a height of 5 cm above the ground.


In terms of planting distance, the current trend is to plant in 4 rows (60 x 15 cm) (non-specialized nurseries) or 2 rows (40 x 20 or 60 x 12.5 cm) with aisles of at least 1 m (specialized nurseries) , that is, with a density of 6 to 8 plants / m2. Thus, easier maintenance is achieved and investment is reduced.


7.3 Fertilization


Currently, fertilization is carried out by irrigation, taking into account the base fertilization, if applied. Subsequently, it is also necessary to monitor the parameters of pH and electrical conductivity of the soil solution, as well as the results of the analysis of leaves.

The pH can be adjusted by adding acid and using fertilizers. For example, nitrogen sources such as ammonium nitrate and ammonium sulfate are acidic, while calcium nitrate and potassium nitrate are alkaline fertilizers. If the pH of the soil tends to increase, the use of ferrous sulfate gives good results. 

Potassium is usually used in the form of potassium nitrate, phosphorus in the form of phosphoric acid or monopotassium phosphate, and magnesium in the form of magnesium sulfate.


Two-year-old shrubs have already formed the basic structure of the shoots and should be planted in such a way that the grafting site is at ground level or slightly buried. 

The first flowers will tend to form on relatively short shoots, and what should be aimed at is the production of branches and a lot of foliage before flowering begins, for which the first flower buds are identified as soon as they are visible. 

The main shoots are cut four or six buds from the base, and the weak ones are completely removed. You can leave one shoot per flowering to confirm the authenticity of the variety.

It should be borne in mind that pointed flower buds will produce short-stemmed flowers and are located at the base of a single-leaf leaf, a three-leaf leaf, and the first five-leaf leaf below the flower bud of the stem. 

In the lower half of the stem, the flower buds are quite flat and these are the ones that will give rise to long-stemmed flowers, so when the shoot sprouts, it is necessary to remove the entire upper half to a point below the first leaf of the five leaf blades.

Subsequently, pruning is done each time the flowers are cut, following the above principles.

7.5 Growing without soil


In recent years, cultivation without soil has become a very viable alternative way of growing roses. This method was developed due to pathological (due to Verticilliun dahliae) and agronomic problems (soil depletion).

Of the 4 possible methods (rock wool, gutters, mats and containers), the first two are the most widely used. The gutters can be filled with the following substrates: perlite, sand, bark and plant fibers.

The floor in the greenhouse must be level to ensure even irrigation (0.5% slope). It can be completely covered with a white cloth to avoid possible soil contamination. 

Grow mats are usually supplied in modules 1 or 2 m long, 7.5-10 cm thick and 15 to 20 cm wide. Some growers install them on 50-80 cm beds to facilitate collection and handling and improve sanitation.

Due to the thin thickness of the substrate (7.5-10 cm), the plants will be smaller than in traditional culture: mini cuttings and mini grafts.

 After planting (usually in March) the plant grows naturally for 4-5 weeks, and depending on the variety, it is necessary to prevent the formation of a dome-shaped structure, which promotes the formation of shoots on which flower buds are suppressed. After 1 or 2 such techniques, a wave of the first flowers is observed in a month and a half.


In the case of perlite gutter cultivation, the choice of planting material is different from that used for traditional soil cultivation.


When propagating, 2 methods are used: grafting of the variety (free position) and semi-grafting. The first method is performed with cuttings of cuttings with leaves (or with a single leaf) placed directly in a container for commercial growing, such as a rock wool cube. 

In the second case, a simple English grafting is performed on a shoot segment of the same type as for cuttings. Mini-grafting is used for some varieties that are difficult to propagate by cuttings, such as the Dallas variety.


Benefits of growing without soil:


Higher productivity compared to traditional crops (10-30% increase, depending on varieties).

The quality is comparable to continuous cultivation.

Excellent sanitary conditions.


8. Rose pests, diseases and physiopatologies

ROSE PESTS, DISEASES AND PHYSIOPATOLOGIES

8.1. Pests


Spider mite ( Tetranychus urticae )

It is the most serious pest in rose cultivation, as it is very quick to attack and can cause significant damage before it is recognized. It develops mainly when the ambient temperature is high and the humidity is low.

In the beginning, the affected plants show streaks or small yellowish-white spots on the leaves, later a cobweb appears on the underside and, finally, the leaves fall off.


The control

Avoid very low hygrometric levels combined with very high temperatures (over 20ºC).

Release of Phytoseiulus in the early stages of infection.

Due to the large number of generations and their overlap, especially in summer, the acaricides used should have an ovicidal effect and an effect on adults. Treatments with acaricides such as dicofol, propargite, etc. give good results, although the most active substance is abamectin.

Green rose aphid ( Macrosiphum rosae )


This is a 3 mm long green aphid that attacks young shoots or flower buds, which later show discolored spots that spread to later petals. A dry and not too hot environment encourages the development of this pest.


The control


For specific control, pyrethroids can be used.

Nematodes ( Meloidogyne, Pratylenchus, Xiphinema )

They affect the underground part, often causing galls on the roots, which subsequently rot.


The control


Soil disinfection.

Immersion of roots in nematicide.

Thrips ( Frankliniella occidentalis )

Thrips take root in closed flower buds, develop between petals, and also at the tops of shoots. This leads to deformities in the flowers, which also show streaks, usually white, due to tissue damage as a result of feeding on thrips. The leaves that these pests feed on are deformed around them.


The control


Preventive control is important because the pest damages the flower, which devalues ​​its value for sale. Prophylactic treatment should be carried out from the very beginning of blooming until the flower buds begin to open.

For chemical control, spraying is used so that the active substance penetrates the kidneys. Various active substances alternate, among which acrinatrine and formethanate can be distinguished.

8.2. Diseases


Downy mildew ( Peronospora sparsa)

Causes the most dangerous disease of roses, provoking rapid defoliation, and if not stopped in time, it can be very difficult to restore the plant.

It develops favorably in conditions of high humidity and temperature, which leads to the appearance of uneven brown or purple spots on leaves, petioles and stems in areas of active growth. On the underside of the leaves, the fruiting bodies of the fungus can be seen forming small gray areas.


The control


Adequate ventilation must be maintained in the greenhouse to avoid this disease. In addition, dew should be avoided on the plant as it promotes conidia germination.

Methods of prophylactic use should be applied using a combination of metalaxil + mancozeb and therapeutic action with oxaditil + folpet.

Oidium ( Sphaerotheca pannosa )

Symptoms, white and loose spots, appear on delicate tissues such as shoots, leaves, flower buds and thorns. The leaves also deform by curling and bending.


The control


Proactive control is very important as it is very costly to mitigate major attacks. The use of sulfur compounds is recommended.

It is necessary to control the temperature and humidity in the greenhouse, and avoid excessive tissue juiciness and reduce the amount of inoculum by eliminating infected tissues.

For therapeutic treatments, propiconazole, bupirimate, and diclofluanide can be used.

Rust ( Phragmidium disciflorum )


It is characterized by the appearance of orange pustules on the underside of the leaves. Usually appears in places where there is moisture.


Excessive nitrogen fertilization contributes to the appearance of rust. On the contrary, summer drought and potash fertilization slow down its development.


The control

It is necessary to control the environmental conditions, and also apply sprays with triforin, benadonil, captan, zineb, etc.

Gray rot ( Botrytis cinerea )

Its development is favored by low temperatures and high relative humidity, which leads to the appearance of fungal infection in any growth zone, flowers, etc. Similarly, it is necessary to be careful with possible wounds that arise during the pruning process, since the pathogen can easily penetrate into them.


The control

To combat this disease, preventive practices are essential, such as keeping clean, ventilating, removing diseased plants or plant parts, and treating with iprodione and procymidone fungicides.

Bacterial cancer ( Agrobacterium tumefaciens )


Agrobacterium tumefaciens growths or bulges form on the stem up to 50 cm above the ground or on the roots, penetrating through wounds when the plant develops on contaminated soil.


The control


The soil must be sterilized before planting, preferably with steam.

Plants showing symptoms of the disease should be destroyed.

Biological control is possible with Agrobacterium radiobacter, strain K84.

Sheet mosaic


This name includes various viral manifestations that affect the foliage of roses. The most common symptom is intermittent zigzag chlorotic lines, usually asymmetric to the central vein.

 Chromatic changes can be accompanied by twisting and deformation of the sheet. On the same plantation, the degree and severity of symptoms vary from year to year and never appear on all foliage, limited to some shoots or groups of leaves located on the same shoot. At the same time, other parts of the plant remain visually healthy.

Although viral morbidity does not always affect the development of the affected crop, some studies have found delays in flowering and reduced plant life.

The control

The prevention of viral diseases is based, on the one hand, on the fight against agents that spread the infection: aphids, ticks, thrips, etc .; removing weeds inside and outside the greenhouse and preventing mechanical transmission, as sometimes the latter is the only way of infestation. Thus, the preventive measures to be taken into account are as follows:


Destruction of sick and suspicious plants.

Instruments used for propagation, cutting flowers and leaves should be sterilized in 2% formaldehyde solution and 2% sodium hydroxide solution for 6 seconds. You can also use trisodium phosphate (377 g / liter of water) or heat treatment at 200 ° C for two hours.

Use two sets of cutting tools and gloves. When working with one, the other must remain immersed in the solution for the time necessary to sterilize it from any viruses that may be present on it.

Do not use contaminated substrates from under infected roots or drainage water from under viral plants.

Do not reuse bamboo stakes. Use aluminum ones because they can be sterilized.

Review every two or three years when new varieties are introduced.


8.3. Physiopathology


Falling leaves can occur for various reasons. On the one hand, any sudden change in the level of growth can determine some degree of defoliation, since the area around the petiole expands rapidly, increasing the diameter of the trunk at this point, while the base of the petiole consists of meristematic tissue that cannot expand, which leads to rupture of the petiole tissue and, consequently, leaf fall. Diseases leading to ethylene production can also cause defoliation, the same effect occurs in the presence of gases such as sulfur dioxide and ammonia.

Also common are phytotoxicities caused by phenoxide-type herbicides, which can cause severe symptoms of twisting and curling of young leaves and shoots.

Sometimes the petals appear shorter than usual and are abundant in what is known in some places as a bull's head. Thrips are blamed for these symptoms, although these flowers usually appear in the absence of thrips on very strong stems.


9. Shear 


As a rule, flowers are cut at different stages, depending on the time of harvest. Thus, in high light conditions during the summer, most varieties are cut when the sepals are open and the petals are not yet unfolding. 

However, flowers are cut in winter when they are more open, with at least two outer petals without unfolding. If they are cut too immature, the head may wilt, and the flower is not rigid, since the conducting vessels in the stem are not yet sufficiently lignified.

In any case, you should always cut off the stem with 2-3 buds that correspond to full leaves. If we cut too early, bent neck problems can result from insufficient lignification of the vascular tissues of the flower stem.


10. ROSE STORAGE AFTER CUT

ROSE STORAGE AFTER CUT


In the post-cut period, several factors are important, first of all, it must be borne in mind that each variety has a different cut time, therefore the level of maturity of the bud and peduncle will be decisive for the subsequent development of the flower from the moment of its cut.

After cutting the flowers, factors that can affect their wilting are: difficulties in absorbing and moving water by conducting vessels, the inability of flower tissue to retain water, and changes in intracellular osmotic concentration.

The cut stems are placed in trays or cubes of nutrient solution, removed from the greenhouse as soon as possible to avoid wilting by leaf transpiration. They are immersed in hot nutrient solution and quickly cooled. Before forming bouquets, flowers are placed in water or in a nutrient solution containing 200 ppm aluminum sulfate or nitric acid and 1.5-2% sugar, in a cold room at a temperature of 2-4ºC to avoid the spread of bacteria. If only water is used, it must be changed daily.

Once the flowers are moved out of storage, leaves and thorns are removed from the bottom of the stem. Later, the stems are classified by length and selected to be curved or with deformed and damaged flowers.

Stem length classification can be done manually or mechanically. Nowadays there are many rose apparatuses that perform calibration. These machines have several sorting lines for different lengths. Their use reduces labor intensity.

Unlike the previous operation, the quality of the flower is determined only manually; it can be supplemented with some simple mechanism.

Finally, they move on to forming dozens of bouquets, which are covered with plastic wrap and returned to the warehouse for additional refrigeration (4-5ºC) before packing, since cut roses require several hours of cold before entering the market.


11. Commercial distribution  


The classification of roses is made according to the length of the stem, there are slight differences in the classification criteria, they are outlined as follows:


EXTRA: 90-80 cm

FIRST GRADE: 80-70 cm

SECOND GRADE: 70-60 cm

THIRD GRADE: 60-50 cm

SHORT: 50-40 cm

Classification of mini roses:


EXTRA: 60-50 cm

FIRST GRADE: 50-40 cm

SECOND GRADE: 40-30 cm

SHORT: less than 30 cm

It is important to keep in mind that EXTRA quality roses, in addition to maintaining the length and stiffness of the stem, must have a flower bud, proportionate and well formed, and the health status of the leaves and stem must be optimal.


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