Orchid care

Temperature requirements

Before deciding how to care for orchids, you need to understand how they grow in nature, what they need to be happy. And the living conditions of orchids are very different in different habitats. Scientists biologists give various classifications of orchids depending on temperature and humidity. The most common division of orchids into three classes depending on the temperature of the habitat. For example, it is described by Frank Relke in the book "So they grow best" (Lick Press, 1998).

The author has the following characteristics:

And such a classification is very conditional, such an extensive family, numbering dozens of species, and growing in all corners of the globe, cannot be limited to three zones .

However, Frank Relke points out that many orchids do not need to strictly maintain the temperature limits indicated by him. Indeed, the orchid culture is known for its plasticity, the ability to adapt to environmental conditions, of course, within reasonable limits. Unfortunately, I was unable to establish who Frank Relke, the author of the book Orchids, known in certain circles, is. That's how they grow best." Who is he? Where you can see his collection of orchids, or find out what formed the basis of his book. But one way or another, I turn to another classification, in my opinion, more broadly describing the habitat of orchids.

The author Gustav Schoser, who was the director of the Palmengarten Botanical Garden in Frankfurt am Main, is an orchid collector, he wrote the book Orchids, about growing them at home, breeding and caring.

According to Schoser, four types of orchid habitat can be distinguished:

Areas with permanently warm humid climates	Areas characterized by a change in rainy and dry seasons, the duration of which is different at different points on the Earth	Orchids in areas with warm, dry weather during the day and cool, wet nights	Orchids in mountainous areas of the tropics with constantly humid and cool climates
The equatorial zone is the land belt richest in precipitation.	North and south of the equatorial belt, the border of which runs along 10 ° north and south latitude, for example, areas of Southeast Asia	Adjacent to the tropical belt with a warm seasonal climate are areas characterized by a warm, dry climate with cool, wet nights.	In the mountainous regions of the tropics in the high-altitude zone from 1000 to 2300 m above sea level. These are the high-altitude belts of Colombia, Venezuela and Peru, the mountain forests of the Andes, the Co-Lumbian and Venezuelan Andes.
The average annual temperature ranges from 24 to 33 ° C. The difference in temperature between day and night is insignificant and averages 7 ° C.	The average daily temperature is about 21 ° C. The difference in temperature between day and night is 8-11 ° C.	Daily temperature drops in the dry season are up to 12 ° C.	The average daytime temperature is about 24 ° C, nighttime temperature is about 16 ° C. In the forest zone, daily fluctuations are about 3-4 ° C. The soil temperature during the day is up to 22-23 ° C.
Uniform heavy precipitation and high temperature cause constantly high relative humidity (80-100%).	Precipitation to varying degrees from spring to autumn, the bulk of the rain in summer is the wet period. The drought period occurs in the winter months of November - January (3 months).	The seasonality of the climate is much sharper than in the previous climatic zone, and the drought period lasts up to six months.	At least 2000 mm of precipitation falls here per year. At an altitude of 2000-3000 m above sea level, moisture condensation, large clouds form. At an altitude of 800-1500 m above sea level, the forest zone and forests are called cloudy.
Due to the lack of need to survive the dry period. many orchid species lack pseudobulbs.	For these orchids, the presence of fleshy bulbs and roots storing water is typical.	For these orchids, the presence of fleshy bulbs or thickened fusiform pseudobulbs is typical.	Among this group of orchids, sympodial orchids with pronounced pseudobulbs, or reduced, are more common.
Phalaenopsis phalaenopsis, Vanilla vanilla	Cymbidium Cymbidium, Ansellia Ansellia, Brassia Brassia, Brassavola Brassavola, Vanda Vanda, Renantera Renanthera, some phalaenopsis Phalaenopsis, Paphiopedilum paphiopedilum, Spathoglottis Spathoglottis, Ludisia Ludisia, Anectochilus Anoectochilus, Cattleya Cattleya, Lelia Laelia, Oncidium Oncidium, Odontoglossum Odontoglossum	Cycnoches Cycnoches, many lelia, Dendrobium dendrobium, Oncidium oncidium.	Masdevallia Masdevalli, Epidendrum Epidendrum, most species of odontoglossum Oncidium of the genus Ada Ada.

Not everything in this table is literal, I tried to reduce the main thing, for clarity. Many amateurs operate with just such zoning of the natural habitats of these plants. Now let's think about what it gives us?

Only an approximate idea of ​ ​ what different corners of the planet orchids inhabit. For keeping orchids at home, it is important for us to know the temperature at which the plant will be fine and humidity. Here you still need to think about how to say correctly - the humidity of the substrate or air is probably more correct to say the need for moisture (and how to moisturize is secondary).

As for the temperature, at home in the spring-summer period, it practically corresponds to the type of orchids required by many during the growth period (if not above 25-28 ° C). The decisive factor is the diurnal temperature fluctuations, which for some orchids are necessary for successful flowering. And also the period of rest necessary for certain orchids. But basically, the exact and clear boundaries of temperature norms belong to species orchids, and at home there are still hybrids for which all boundaries are somewhat smoothed.

By the way, the fourth category - mountainous regions of the tropics with a constantly humid and cool climate gives a very lengthy idea of ​ ​ the realities of life in the mountains. The fact is that temperature and humidity vary greatly at different altitudes. Take, for example, Masdevallia - an extensive genus, whose representatives grow in the mountains, but it is also customary to divide them into 4 groups:

I give these figures not as a guide to the cultivation of masdevallia, but for clarity how the climate in the mountains is changing. Moreover, the authors describing historical places, as a result, give recommendations like these: "Masdevallia need cold or moderate content. The plant needs winter temperatures: at night 15 ° C, during the day no more than 18-19 ° C, i.e. very average and smooth the boundaries between all four groups. But orchids have survived in such a huge species diversity for millions of years, all thanks to their incredible plasticity, survivability and ability to adapt to environmental conditions. Therefore, general recommendations on the moderate temperature regime of masdevallia are justified.

In fact, many orchids grow at home in summer and at higher temperatures, on our windowsills they are forced to bend under weather conditions. When it is hot summer and outside + 40 ° C for several days, maybe a couple of weeks, both orchids and people have to adapt. And by the way, cold orchids also survive in such conditions. Here it is important not to allow the plant to overheat, not to allow heating. If there is no air conditioner, then this is achieved primarily by shading, as well as good air ventilation, i.e. not just open the window, but fan operation. Creation of finely dispersed dust, i.e. fog or spraying. The movement of air at high humidity does not allow mass development of infections (fungal and bacterial) for which dampness and heat are the best conditions for progression on orchids .

How to water orchids

As for watering and moisture-intensive substrate at high temperatures, this is a very dangerous moment. I don't know what this is dictated by, but it is the increase in watering that is characteristic of lovers of indoor flowers when setting hot weather, or during the heating season in winter. In fact, going through the topics of diseases and errors in growing any plants, you come to the conclusion that the problem of decay from diligent irrigation comes first. And all other troubles in terms of the frequency of cases are far behind.

But water only compensates for the heat up to a certain point! A person suffering from heat can drink a liter of water, but not a bucket! The same with flowers, the plant is able to absorb, pass through its root system only a certain amount of moisture. Everything else is not absorbed, but the moss absorbed water is a nutrient medium, like agar-agar in a petri dish, for any unnecessary infection.

If someone makes an argument in favor of excess irrigation, about the humid tropics, where it rains constantly, then this is also not correct. Many orchids are epiphytes and grow on any surfaces, their roots are not in the substrate as such, and therefore all the water that falls on them very quickly flows down and evaporates. If you compare them with other ancient neighboring ferns, then this is who is a real hygrophyte. It is ferns, selaginella, maranta and madder that are hygrophytes and form the lower grass layer of the rainforest.

Orchids, firstly, are out-of-tier vegetation of the rainforest, they grow at different heights and are not tied to a specific tier. Here is an excerpt from the diary of Andrei Kuznetsov, a botanist, a scientist who worked in the mountains of northern Vietnam, at an altitude of 1800-2300 m above sea level: "In the rainforest, we found "beards" of lichens and mosses. They hung on the upper branches, and tropical orchids hung from the lower... lingonberries. Obviously, the existence of "our" plants here is associated with a sharp drop in air temperature in the winter months (October - February) to -5 ° with an average air temperature of + 5 °." ("Around the World," No. 3 1994)

Secondly, orchids are succulents! It is, like cacti or stoats, that orchids have developed a way to survive periods of drought, store moisture in roots, leaves, bulbs, and even the absence of pseudobulbs - not at all an indicator of moisture lovers. Belonging to succulents in orchids confirms the presence of CAM-type photosynthesis.

In addition to orchids, we also know other epiphytes, for example, bromeliads (many of them are also succulents). We know that they have a different structure from orchids and root systems, and leaves. They adapted to collect water in leaves located in a rosette or funnel, and absorb nutrients from it. For example, Tillandsia Tillandsia leaves are equipped with hairy scales - trichromes. They absorb moisture and mineral substances of precipitation and dust directly from the air.

Then what kind of adaptations do orchids have? Their adaptations are roots. They have a special structure that allows you to absorb water: the roots are usually covered with a thick, protective layer of dead cells called velamen. Velamen functions as a sponge, absorbs moisture and nutrients. When it gets wet, the roots become translucent, and look green, because under the layer of velamen there is a living green epidermis. When the velamen dries, the roots turn white if the velamen layer is thick enough, or only bluish, whitish green if the velamen layer is thin. The thickness of the velamen layer directly depends on how wet the environment around the roots is.

If the orchid grows on the block and its roots are open, and periods of moisturization alternate with rapid drying (drying in 3-4 hours), then the layer of velamen is very thick, the roots are almost white and only at the tip remain green.

If the orchid grows in a layer of constantly moist substrate (for example, sphagnum moss), then the velamen on the roots is very thin, or almost completely absent. Why is this bad? The fact that such roots are not adapted to dry content, velamen does not protect them, as soon as the moss dries, the roots begin to dry out. In addition, they are very fragile, scratches and cracks are easily formed on them, where the infection gets and decay occurs. The rhizome also easily rots in orchid if it is not above the surface of the ground.

Under natural conditions, most orchids are epiphytic, with an open root system. Roots, like other organs of orchids, breathe, when breathing, they absorb oxygen and release carbon dioxide. At home, the requirements of orchids do not change - for the normal growth and development of the plant, it is necessary that fresh air constantly flows to the roots. If the orchid is in a constantly moist environment, or completely in water, the roots stop breathing.

How are hydroponically grown plants, including orchids? Indeed, there is such an experience, but you cannot just place the plant in an enclosed pot of water and expanded clay, and wait for prosperity. When grown on hydroponics crops, there are rules and subtleties, for example, the solution is saturated with oxygen using ordinary aquarium pumps, and air bubbles come to the roots with water. In addition, in hydroponics it is very important not to exceed a certain water level, and usually the inner pot is lowered into the nutrient solution no more than 1/3 of the height, and there are special water level marks for control.

But back to the care of epiphytes, the issue of watering. What should be guided by? First, the moisture capacity of the substrate. Not all orchid lovers grow on blocks, many grow them in pots, using a different ratio of components as a substrate: bark, coconut fiber and moss. The greater the amount of sphagnum moss in the substrate, the longer it will remain moist. Sphagnum moss is very hygroscopic, so you have to be very careful with it, it is not a natural neighbor of orchids in nature! Under natural conditions, sphagnum moss does not grow in trees. Lichens grow on trunks next to orchids, these are completely different plants. And sphagnum moss was invented by amateur growers, apparently just like in any other plants.

You can add to orchids per block or cover the bark in pots with moss from trees (its branches are leathery and hard do not absorb water well). It dries very quickly and lets in air well, while the sphagnum sticks together into raw lumps.

The most moisture-intensive substrate is pure coconut fiber. It does not absorb water, does not stick to the roots, does not stick and does not cake for a very long time. But it sheds roots from sunlight, protects against overheating. Therefore, it is used on blocks, and in baskets, and pots. But if the orchid is planted or wrapped only in coconut fiber, it should be moistened more often than if it were sitting in the bark.

How often to moisturize... I still won't get to specific numbers. In fact, it depends again on the temperature. Hydration should be such for most epiphytic orchids that the roots dry and remain dry for at least several hours, 1-2 days during the growth period, and several weeks or months during the flowering period (in different species in different ways).

I must say that in nature, the distribution of precipitation within different areas of the rainforest is uneven. There is an alternation of periods of short drought and rain. Dry periods in a tropical wet forest do not last long, but this is not a complete absence of precipitation, but simply rarer rains - on average every three to four days. In the rainy season, there are showers every day, they can be short-lived or last several hours. But at the same time, the roots are constantly in the fresh air, they breathe! If you have a plant in a pot, this is a different microclimate. There is no air movement in the pot, especially if the pot is filled with bark or something else.

Tropical rainforest orchids with uniform warm environments throughout the year hydrate differently during different periods of development. For the rainy season, these orchids, take phalaenopsis for example, have a growing season, leaf extensions. Moisturizing occurs every two to three days so that the roots have time to dry well. If they do not dry out, then either revise the composition of the substrate, or water even less often.

With the end of vegetation, the frequency of watering is reduced, i.e. as soon as a pause in the appearance of a new leaf - watering can be reduced. In the dry period, according to the laws of nature, the same phalaenopsis should be watered or soaked less often, so that the roots are dry for at least 4-6 days.

Orchids are moderately heat-loving, from places with a pronounced dormancy period, they should also dry out during the growing season and remain dry for 4-5 days. Moreover, it is important that the substrate in pots with orchids dries very quickly. About a day after watering. We must constantly remember about the succulent nature of orchids, they are not related to marants and cyperuses.

With the end of the growing season, they are placed in cooler conditions, and first the frequency of watering (soaking) is reduced, to about once every two weeks. And then they stop altogether. Moreover, many of them have pseudobulbs. Cymbidium, Wanda, dendrobium, oncidium, cattleia, lelia, etc. should have a dry period of at least 3 months, but many of them are able to survive a longer dormant period.

Cold orchids need moderate moisture, i.e. water them in the same way, after drying the substrate. During the growing season, in summer, if it is hot, then 2-3 times a day, the air should be moist, and not the soil in the pot.

Cold orchids grow in conditions of high humidity all year round. Their root system is mostly open. In addition, there is a constant movement of air in nature. For example, bulbophyllums are found in char (mountain peaks), which, as a rule, rise above the upper border of the forest, i.e. these are open blown areas where the growing conditions are practically xerophytic (arid), in the same place on trees and rocks coelogines live, where there is even greater air movement. And the highest humidity, fogs and streams between rocky ledges, in decay, ferns, aralia, saxifrages, sedge, balsamines grow there.

Another cold orchid: some species of masdevallia and odontoglossum also grow in mountainous areas, like epiphytes or lithophytes. They also need high humidity all the time, with very good ventilation (constant flow of fresh air). During the growth period, the temperature is moderate about 15-20 ° C during the day, during the dormant period from November to February or longer, the temperature is 10-15 ° C, depending on the species, and mandatory daily changes throughout the year.

At such low temperatures, you need to water orchids very carefully, because evaporation of moisture occurs very slowly. If the soil does not dry out, but remains moist for several days, then orchids easily rot, even very non-capricious species. Therefore, watering may be absent as such at all, and be completely replaced by spraying. It is impossible to add moisture-retaining components to the substrate for refrigerators, although this, it would seem, at first glance, contradicts their moisture-loving nature. In fact, in practice, it is very difficult to find an equilibrium between high air humidity and a moderately humid substrate, so moss sphagnum, vermiculite, a large amount of bark, must be replaced with stones, coconut fiber or other neutral components (for example, pieces of foam).

Most orchids come from areas with a seasonal climate, where the change of rainy and wet seasons occurs two or more times a year. Therefore, different types of orchids have a pronounced or almost imperceptible dormant period, during which flower buds are laid.

Heat-loving orchids need a slight decrease in temperature, to 15-16 ° C, moderately heat-loving orchids - a little lower than 13-15 ° C, cold-loving orchids - up to 10 ° C. But it depends on species needs, for example Oncidium brilliant Oncidium splendidum grows on rocky slopes, in Mexico and Honduras, at an altitude of about 825-850 m above sea level, adjacent to thickets of cacti and agaves, it is more heat-loving (rest at 16-18 ° C), compared to Oncidium flexuosum (12-15 ° C), which grows epiphytically in trees, along streams and swamps, at an altitude of up to 1200 m from sea level in Brazil, Paraguay, Argentina. But this applies mainly to natural species, they are usually grown by professional orchid collectors. The bulk of amateur orchidists grow hybrids, and they are less demanding on rigid temperature frames.

And yet, returning to the biological cycles of orchids: vegetation, leaf growth occurs during the wet period, flowering - on the dry. Therefore, along with a decrease in temperature, a signal to change the season for orchids is an increase or decrease in watering (abundant rain spraying is equated to watering). If with the beginning of the growing season everything is simple - the growth of new leaves is immediately noticeable, then the beginning of flowering is more difficult to "catch." After all, flower buds are laid at the end of the vegetation, and are not noticeable at the beginning of growth. Therefore, to reduce watering, for successful flowering, it is necessary in advance, while the leaves are still unfolding. From about the middle of the growing season, watering begins to be reduced so that by the end of the growth period and the beginning of flowering, the orchid is moistened to a minimum. I.e. only humidification of the air to prevent excessive wrinkling of pseudobulbs.

Another question about watering should be added that orchids with different root conditions should also be moisturized in different ways. Indicator - the presence of velamen on the roots. If the velamen layer is good - this is noticeable at the very tip, the transition from light green to white is clearly visible, which means that the plant is ready to calmly tolerate drying of the substrate. If velamen is thin, almost invisible, then it must be gradually accustomed to drying. Gradually increasing the time when the roots remain dry.

Often, it is the wrong, sharp transition from one growing mode to another that causes the disease state of the plant.

The following materials were used in the preparation of the article

Natalia Rusinova