The rubber tree is very popular with us as a houseplant. Here you will learn everything important about the care, pruning, and propagation of the rubber tree. Many have the tree with the impressively large leaves in their room or office, but there is certainly much worth knowing that you may not yet know about the rubber tree (Ficus elastica). For example, did you know that the ficus is actually a member of the fig family and that its sap can actually be used to make rubber for gum? We have compiled more interesting and interesting facts about the popular rubber tree for you here. You will learn everything about the origin, different varieties, purchase, location, care, and typical disease patterns on the rubber tree.
Like the Edible Figs (Ficus carica), the rubber tree belongs to the genus Ficus, i.e. to the fig family, and thus to the mulberry family (Moraceae). It is classified in the group of banyan figs, to which also belongs the poplar fig (banyan tree), which is significant in Buddhism. According to Buddhist tradition, Siddhartha Gautama experienced “enlightenment” while sitting under a poplar fig and thus became a Buddha.
Another name is the Indian rubber tree. Both names already indicate the use of the sap of the plant, because it contains rubber, from which rubber can be made. However, this is a rather time-consuming undertaking: It takes a full seven years before rubber can be harvested for the first time after planting. Under ideal conditions, the rubber tree can live up to 100 years, during which time rubber can be extracted from it up to 30 times. However, today the rubber tree is hardly used for rubber production. Mainly only the rubber tree (Hevea brasiliensis) comes into question for this.
In our country, the tree has much more of an aesthetic function and is used as an ornamental plant. While the rubber tree was so popular in the 1980s that it was felt that everyone had it in their homes, the hype surrounding the tropical tree quickly died down afterward and it disappeared from rooms and offices once again. Today, however, the rubber tree is experiencing a revival and is once again making its way into our homes. The main reasons for its popularity are obvious: the rubber tree is beautiful to look at, robust, and easy to care for. Also, it has been proven that the tree can filter formaldehyde from the air and thus contribute to higher air quality in the room.
Even Frank Sinatra was so enthusiastic about the Rubber Tree in 1961 that he even wrote a song about it called “High Hopes”. One last piece of information worth knowing about this special ficus: In parts of India, people lead the roots of the tree across gorges and rivers. This creates very impressive so-called living bridges.
Rubber tree: origin and characteristics
The rubber tree has its original home in an area from northeast India (Assam) to Indonesia (especially on the islands of Sumatra and Java). Today, however, the Ficus elastica is cultivated worldwide. In tropical climates without frost it thrives splendidly outdoors, in colder climes it is convincing as a houseplant.
In the wild under tropical conditions, the tree can grow up to 40 meters high. Its trunk can reach a diameter of up to two meters. Ficus elastica is a tree-choking hemiepiphyte (strangler fig). The bark is light brown to medium brown and smooth. The trunk may also develop aerial roots in the wild to anchor itself more firmly in the ground or to support heavy branches. However, this does not occur in the pot. Young plants of the rubber tree can even grow as epiphytes, or perching plants, without contact with the soil.
After all, as a houseplant, the tree grows up to two meters in height, if left. The leaves of the tree are up to 30 centimeters long, thick and leathery. They grow alternate and broadly oval with pronounced leaf tips. The petioles can grow two to five centimeters long. The leaves are shiny and dark green on the upper side, the underside is light green.
If it comes to flowering and fruits, it becomes complicated with rubber trees as a houseplant. In the pot, the tree seldom forms flowers. These are only pollinated by a very specific species of wasp – and only then can the tree develop fruit.
Rubber tree flowers: When does the rubber tree bloom?
Yes, rubber trees are capable of producing flowers and subsequently small fruits. But popular houseplant species such as rubber trees and their cousins, the vine figs (Ficus Benjamina), rarely bloom and, accordingly, rarely bear fruit. Actual rubber tree flowers are small, greenish, and inconspicuous. They are very unlikely to occur on a plant growing indoors in a pot. Even in rubber trees growing outdoors in warm, temperate to semi-tropical conditions, flowering rarely occurs.
As with other members of the genus Ficus, the flowers require a specific species of fig wasp to pollinate them in a co-evolved symbiotic relationship. Because of this relationship, the rubber tree does not produce very colorful or fragrant flowers to attract other pollinators. As fruits, the Ficus elastica does produce small, yellowish figs, but these have nothing to do with the delicious figs we know from the Mediterranean region but are inedible.
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Rubber tree varieties
A rubber tree does not necessarily have only green leaves. Some varieties are characterized by colorful leaf coloring. We have compiled the most beautiful rubber tree varieties for you below:
- Robusta: Probably the most popular variety of rubber trees; as the name suggests, this variety is extremely robust; the leaves are oval and dark green.
- Australis: If you only have a small amount of space available, you should go for this variety of rubber trees, as it impresses with its stocky growth habit.
- Belize: Probably the most colorful variety among the rubber trees; the leaves are red, white, and green variegated.
- Tricolor: This variety also brings color to your rooms; the leaves are dark green with white and pink spots.
- Variegata: Green leaves with yellow areas and yellow leaf edges are carried by this variety.
- Doescher: Also tricolored is this variety; its leaves are green with cream and gray patterning.
- Melany: This variety of rubber tree grows especially dense and bushy; its leaves are dark green with a slight red tinge.
The Perfect Location For The Rubber Tree
For your tree to grow and thrive, it should be placed in a location that is suitable for it. The rubber tree likes it warm and sunny – no wonder since it originates from tropically warm regions. However, you should avoid the bright midday sun, which is not good for the tree. It is also important that the ficus is not exposed to drafts. As is usual in its tropical home, it likes it warm. It feels most comfortable at temperatures between 59 and 64 °F. If the temperature drops below 52 °F, it begins to shiver. Light is also important to the rubber tree, as it likes it as bright as possible. If it is too shady and dark, the tree may lose its leaves. So always choose a place for your tree that is as bright as possible.
Another aspect is the humidity of the air. Too dry indoor air is bad for the rubber tree. It is best to ensure that the humidity is always above 50%.
Summary of location requirements of the rubber tree:
- Sunny to partial shade
- No blazing midday sun
- No draught
- Warm, between 59 and 64 °F
- As bright as possible
- Ideal humidity above 50%
Repot Rubber Tree
As soon as the surface of the substrate in the pot of the rubber tree begins to bulge upwards or the substrate is completely rooted, it is time to repot the ficus. This should be done at least every two to three years. If the rubber tree has too little space in the pot, it can cause it to lose its leaves. The best time to repot is in the spring from late February to early March.
First, mix a suitable substrate for the rubber tree. It is important here that the substrate is as rich in structure as possible and well permeable. Otherwise, waterlogging can occur in the pot, which is detrimental to the rubber tree. With a too high nutrient content in the substrate you do your rubber tree also no favor, it should be better nutrient-poor. As a suitable substrate, you can mix conventional potting soil with perlite, lava granules, or coconut fiber to give structure to the soil, making it more permeable.
Summary ideal substrate for the rubber tree:
- Rich in structure.
- Moderate nutrient content.
- Potting soil enriched with perlite, lava granules, or coconut fibers.
The new pot for your ficus should be only a little larger than the old one. This is the best way for the tree to develop. If possible, choose a planter that is only five to ten inches larger in circumference than the last one. Then create a drainage layer in the pot so that the water can drain away well. Clay shards or expanded clay, for example, are suitable for this purpose. Now fill in a third of the mixed substrate over the drainage layer and place the rubber tree in the center of the pot.
Now fill the rest of the pot with a substrate, leaving about five centimeters free under the edge. Finally, the tree is well watered, but excess water in the saucer is removed.
Summary Repot rubber tree:
- Carefully pull the old pot off the root ball.
- Cut off old, dead, and rotten roots.
- New plant pot: Maximum 20 – 40 inches larger than the old one.
- Create a drainage layer.
- Fill planter to one third with the substrate.
- Place the rubber tree in the center of the pot.
- Fill the planter with the substrate.
- Leave approx. 20 inches high rim of pot free.
- Water well.
Propagate rubber tree
If you can’t get enough rubber trees, you should think about propagating your tree. Fortunately, Ficus elastica is easy to propagate via two different methods: Either via cuttings or by mossing. In cuttings propagation, cuttings are cut from a healthy shoot on the tree and grown in a cutting substrate. This method is easy to carry out. However, it is a little more complicated with the Abmoosen: Here a shoot is cut and divided by a wedge. Then moss is wrapped around the cut, which should stimulate the shoot to form new roots. This procedure is more time-consuming than cutting cuttings. However, if successful, you will have gained an already very large new rubber tree.
For step-by-step instructions on both rubber tree propagation methods, click here.
Care for rubber tree
Fortunately, the rubber tree is considered hardy and therefore requires little care. However, you should still give your tree a little attention. It will reward you with vigorous growth and beautiful leaves. We, therefore, tell you everything you need to know about the correct watering, pruning, and fertilizing of this popular houseplant.
Watering rubber tree
A common care mistake with the rubber tree is watering too generously. The rubber tree is much more forgiving of somewhat prolonged dryness than it is of overly wet feet. Therefore, when watering the tree, you should proceed as follows.
Instructions watering rubber tree:
- Check substrate with the finger test
- Allow the top layer of the substrate to dry out
- Water moderately
- Avoid waterlogging at all costs
- Alternatively water by dipping
Prune rubber tree
The rubber tree is considered to be pruning tolerant but generally does not require regular pruning. Pruning is only necessary if you want to curb the growth of the tree, encourage side shoots, or if the tree is growing unsightly. Of course, you should also reach for the shears if the tree is infested with pests. For pruning, it is recommended to always use clean tools, either a sharp knife or pruning shears. From the cut, wounds come out of the milky-white sap of the plant, which can cause skin irritation and is poisonous. Therefore, always put on gloves when cutting. You can dab the cut wounds with a damp cloth or sprinkle them with lukewarm water.
Instructions Cutting Rubber Tree:
- To curb growth, prune the entire crown.
- To encourage side shoots, cut trunk above “dormant eyes”.
- For upright growth, cut off side shoots.
- Immediately remove dried, dead, and disease or pest-infested.
- Remove plant parts immediately.
- Take care of wounds.
For even more tips and tricks on how to best prune your rubber tree, read on.
Fertilize rubber tree
The rubber tree also doesn’t like too many nutrients. Therefore, when fertilizing, the rule is: less is more.
How to fertilize rubber tree:
- Do not fertilize too much
- Preferably every 3 months with a fertilizer with organic long-term effect.
- Alternatively every 6 weeks with liquid fertilizer
Rubber tree loses leaves
If your rubber tree loses leaves, it is obviously not pretty to look at and you should act as soon as possible. A loss of leaves can have various reasons. For example, incorrect watering, an incorrect location, or lack of space in the pot, incorrect fertilization, or even pets can be causes for such. Therefore, the first thing to do is to find out the cause. Once this is known, you can act accordingly. The following measures will help your rubber tree with leaf loss.
Measures against leaf loss in the rubber tree:
- Change location.
- Repot in a larger container if there is a lack of space.
- If the substrate is too dry, immerse the entire pot in water.
- Repot if the substrate is too wet.
- Repot if overfertilized.
- Treat or use beneficial insects in case of pest infestation.
Common diseases and pests of the rubber tree
If the rubber tree is weakened or the site conditions are not optimal, the likelihood that your tree will be attacked by pests or diseases increases. Therefore, as a preventive measure, you should always ensure optimal growing conditions. The most common reasons for pest infestation are a location that is too warm and air that is too dry.
The most common pests of rubber trees are spider mites (Tetranychidae), scale insects (Coccoidea), and mealybugs (Homoptera). You can recognize an infestation when the leaves turn yellow, dry up, and fall off. Less commonly, the gum tree is also infested by fungus gnats (Sciaridae). Possible means that you can use against the unwanted pests are ecological or even chemical sprays. Proven against pests is, for example, neem oil.
Another way to get rid of unwanted pests is beneficial insects. These are natural counterparts of the pests, which love to eat them and fight them in this way. For example, against spider mites, predatory mites (Phytoseiulus persimilis) help as antagonists. Against scale insects and mealybugs, ichneumonids are suitable beneficial insects. For fungus gnats, the use of nematodes (Steinernema feltiae) can help.
Is the rubber tree poisonous?
As beautiful as the gum tree is to look at, you should definitely not eat from it. This is because the plant parts of the tree contain chlorogenic acid in addition to rubber. This is slightly toxic and therefore the rubber tree is also classified as slightly toxic. Contact with the skin can cause skin irritation or even allergic reactions. If a plant part of the gum tree is swallowed, this irritates the mucous membranes; further symptoms are nausea, vomiting, and stomach cramps. In adults, poisoning is not very severe, but in young children it is different. If there is a suspicion of gum tree poisoning, you should definitely consult a doctor.