Several thousand different cultivated forms of the Orchidaceae such as Phalaenopsis are available in specialist shops. The asparagus-like are not more difficult to cultivate than other ornamental plants, as long as the requirements for the location and the right care are met. Each variety of orchid has individual needs: while some require tropical temperatures and high humidity, other species can easily hibernate in cool places. In addition to proper care, a few tips should also be taken into account when repotting the tropical plants.
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The best time and preparation
The varieties of orchids cultivated on domestic window sills are predominantly epiphytes.
These plants form stable and long aerial roots, which serve to fixate and simultaneously absorb nutrients and water. In the wild, epiphytic orchids are often found on the branches and in the crowns of rainforest giants. In order to promote the growth and health of these asparagus species, you should move the plants to a fresh nutrient base at regular intervals. As a result of the rotting process, the old substrate compacts and the air supply to the roots is no longer guaranteed. Orchids are considered to be extremely true to their location and are sensitive to changes of any kind. Repotting is also perceived by the plant as a disruption, which is why this process should only be carried out about every two to three years.
The orchid is transferred to fresh substrate when the plant is not growing. This depends on the selected variety, some species sprout again in spring, others prefer early autumn for this. The Orchidaceae needs a lot of light and warmth in order to be able to acclimate itself in the fresh substrate. The low-light months November to March are therefore unsuitable for moving the plant.
Before you start repotting, you should have the following materials ready for this measure:
- Sharp scissors or knives
- Larger, transparent planter
- suitable substrate
- Small bamboo or wooden sticks
- Water atomizer
Instructions for repotting
Repotting orchids takes time and care. The sensitive aerial roots must be completely freed from the old substrate before you move the plant into the new container. By carefully deforming the flower pot, it is easier to carefully remove the orchid from the old pot. If there is still resistance, you should cut open the old vessel with scissors, taking care not to damage the roots. In the case of permanently blooming orchid species, you can completely remove the flower stalks before transplanting.
Remove orchid substrate
Carefully detangle the tangle of aerial roots and remove the remaining pieces of substrate with a fine bamboo stick and lukewarm water. You can trim down foul-smelling, mushy, or hollow air roots. Make sure, however, that you remove as few roots as possible in this way so as not to weaken the orchids further. Do not forcibly break apart roots that are massively intertwined. Small amounts of the old substrate do less damage to the orchid than if its roots are damaged during repotting.
Preparing the planter
The asparagus species are also sensitive to waterlogging. If you like to be a little more generous with watering, creating a drainage layer in the planter is recommended. Fine pebbles, expanded clay or lava chippings are suitable for this. Do not use styrofoam balls, as these quickly lose their structure due to the weight of the plant and the substrate. The drainage allows excess water to flow away faster and thus protects the aerial roots from harmful root rot and mold formation. If the orchid has no damaged or diseased aerial roots, moisten the fresh substrate sufficiently with the water atomizer.
the plant in the prepared container and fill it up with new substrate. You can remove possible cavities with the bamboo stick and carefully pressing with your fingers. Only insert the orchid deep enough so that the soil does not come into contact with the new shoots. Excessive contact with irrigation water could weaken and permanently damage the plant parts.
You can stabilize longer shoots with a wooden stick. Plant supports of this type have proven themselves well even with an excessive inflorescence.
The orchid needs about 3 to 4 weeks until the aerial roots have recovered from the procedure and were able to regenerate in the new vessel. During this time the plant is unable to use fertilizer. Watering should also take place after about a week. Treat the Orchidaceae to a bright, warm location.
Be patient: After moving the plant, up to 6 months can pass before the orchid will sprout flowers again. A change in the location or the lack of water and nutrients also delays new growth.
The ideal substrate
Epiphytic plants place different demands on the substrate than conventionally cultivated plants. Inorganic components are well suited to supply the sensitive aerial roots with oxygen. The most popular materials include, for example:
- Lava splits
These substances are also used in hydroponics and, unlike organic materials, do not transfer nutrients or salts to the roots of the orchid. When choosing the substrate, however, the size of the plant also plays an important role. Some materials are not able to counteract the enormous weight of the orchid, so that the stability suffers.
Conventional flower or compost soil is only suitable for terrestrial orchids. Due to the nutrients released, other orchid varieties tend to overfertilize quickly. The suitable organic substrate for plants with aerial roots consists for example of cork, pieces of bark, charcoal, coconut fibers or nut shells.
Notes on aerial roots
The aerial roots of epiphytic orchids often seem to have a life of their own and, much to the annoyance of many plant lovers, also spread across the windowsill. Radical pruning is not always recommended for this type of root, but you can still shorten “outliers” by a few centimeters. Also carry out this measure when your orchids are not growing so that the formation of flowers and shoots does not suffer. To protect against fungal pathogens and pests, you should coat the interface with carbon powder or cinnamon, both materials have a disinfectant effect. However, elastic roots can also be twisted in and tied to wooden sticks. Due to the direct and frequent contact with water, it is not recommended to use sticks and climbing aids made of metal.
Healthy and resilient aerial roots take on a green color when they come into direct contact with water. If this reaction does not occur, you can remove a few centimeters with sharp scissors. However, only remove individual aerial roots; excessive shortening or resection of all root runners will result in the death of the orchid.
Tips and Tricks
The length of the new drives is decisive? It is not just the pause in vegetation that determines the right time to repot: as soon as the new shoots have reached 1/3 of their total size, you can move the orchid.
You should disinfect knives and scissors with a high-percentage alcohol solution before and after working with plants. This will prevent the potential transmission of fungal pathogens and pests to other crops. If you don’t have any alcohol on hand, you can boil the tool or use a lighter to kill any germs that may be present.
As beautiful as it may look, do not use opaque flower pots and planters with orchids. Without light, the aerial roots cannot form photosynthesis, mold and stunted growth are the result.
You don’t necessarily have to use special orchid soil from specialist retailers. Mix your substrate together yourself. For aerial roots, however, avoid normal potting soil and materials with a high proportion of peat and clay.
“Less is more” – this statement applies not only to fertilization, but also to the water supply. Many orchids die because they were watered to death through carelessness and lack of knowledge. The amount and frequency depends on the variety selected, as soon as the substrate layer has dried noticeably, you can pour it in moderately.
Orchids often stop growing for a while, especially after repotting. During this time you should only water in small quantities, but do not leave the plant to its own devices. You can increase the humidity with a water atomizer, which is particularly recommended when the air in the heating system is dry.
If you repot in the spring, you can use this measure for the simultaneous increase of the orchid. To do this, the bulbs are cut off with a disinfected knife and converted into a suitable substrate. High humidity and warm temperatures ensure that the young offshoots grow faster. The division of the roots has also proven itself in some older orchids.
Repotting caused by disease Putrid smelling substrate is a sure sign of already existing root rot. Not only does excessive waterlogging promote such a process in aerial roots, but an air-impermeable substrate can also contribute to this. Regardless of the season, you should repot the affected orchid. Gently remove rotting roots with sharp scissors and avoid adding water for a few days. If the stage of root rot has not progressed too far, the plant will recover afterwards. Repotting the orchid is also often advisable and advisable for successfully combating pest populations.
In order to repot orchids, you do not need to have a PhD or attend a botany seminar. A little preparation and patience are enough to successfully move plants with aerial roots into fresh substrate without any consequential damage.