Balsam apple, Clusia major – care and propagation

The balsam apple is a succulent tropical plant that likes to be warm and cozy all year round. At least 20 °C, if possible not below that even in winter, and really bright. In its homeland, the balsam apple gets at least 12 hours of daylight. If you read that a balsam apple can withstand temperatures of 12 or 16 °C, that might even be true. But then it’s all about “enduring”, not about magnificent growth.

If you already have a balsam apple at home because it gave you a friendly smile the last time you visited the furniture store, you should probably repot it first. The Clusia major sold in the furniture store is already a “real green plant” with a plant height of about 30 cm, but sits in a flower pot with a diameter of 12 cm, from which it should be freed as soon as possible.

growth and substrate

Clusia major can develop into an imposing plant 2-3m tall and 1-2m wide, but certainly not in a 12cm pot. Every hobby gardener knows that plants grow bigger in large pots. A few years ago, researchers also found out how much larger in which pot: double the pot size = a good 40% more biomass, in a 2 liter pot three times as high as in a 0.2 liter pot. In order for a plant to grow without restrictions on the pot size as in the wild, it needs at least one liter of pot volume per gram of dry biomass of the plant. The starting pot of the furniture store Clusia has around 1 liter, its dry biomass should be around 50 g, but for the time being a slightly larger pot is enough.

Regardless of the pot size, a freshly bought Clusia (or any freshly bought plant) should always be repotted after purchase if you can be sure that the substrate used in the pot was not particularly high-quality. You can always assume this if you buy particularly cheaply, because the cheap prices do not arise because a dealer produces particularly high-quality goods and gives you his profit. So: repot, preferably in garden soil, if possible with some clay and with normal nutrient content. With indoor plants, a third of sand can always be mixed in as drainage. Balsam apples also do very well in soilless culture and can be converted to hydroponics.

The care

• Substrate: Mixed garden soil or normal potting soil
• Or hydroponic substrate, completely free from the old substrate
• Lots of light but no direct sun
• Temperature at least 20 °C all year round
• water generously until the leaves appear plump
• Ensure high humidity by spraying or by watering a bowl under the planter
• Both with low-lime water, rainwater or stagnant tap water
• Water should be at room temperature
• Plant pot needs a drain so that no waterlogging can occur
• Only give in water again when the surface of the earth feels dry
• Fertilizer: half concentration, every 14 days in the growth phase

You can often read about the flowers that appear from June to August and the intense vanilla scent that they are said to exude. However, it is unlikely that these flowers will actually appear in summer. The balsam apple almost never blooms in Central European cultivation (you may have a chance to see blooms with a grow light).

You should always repot the Clusia when the plant pot is well rooted. Depending on what growth you expect from the balsam apple, more or less quickly: Plants adjust their growth to the pot size, the decisive factor is the root volume in relation to the pot size. Only around a quarter of the roots grow in the middle of the pot, half of the roots look for the way to the edges of the pot and grow along them. The conditions there are not the most favorable, eg large temperature fluctuations. When the roots reach the edge of the pot, they stop growing. Then there is only little nutrient available in the earth anyway, and the water storage capacity also reaches its limits. The best time for repotting is spring, when the plant is just starting to grow.

You don’t have to cut a balsam apple, but you can. For example, if it gets too tall, or to promote regular branching in young plants (by also pruning regularly).

Save the balsam apple space on the patio. Clusias are said not to have proven to be particularly suitable for outdoor use in this country. They are used to constant temperatures and should quickly react to a summer with day temperatures of around 30 °C and night temperatures of around 10 °C in a downright bad mood.

Clusia major propagation

As a succulent, the balsam apple is one of the more prolific plants and can be easily propagated in several ways:

Triebstecklinge

Cut off a hand-length piece of the end of the branch and let the cut surface dry for two to three days. Normally, with shoot cuttings (head cuttings, last piece of branch with a few leaves), the lower leaves are removed, which would interfere with planting the cutting. With plants of the Clusia genus, you should also plant the lower leaves – they should often form small shoots in the leaf axils, which pierce the earth from below and continue to grow happily in the air.

Place the branches (not too deep) in seed pots with a loose, nutrient-poor substrate and care for them as described above, succulent shoots usually grow without any special treatment. Only if the planted shoot does not want to stay upright is it given a short stick to support it in the pot.

leaf cuttings

Leaf cuttings are obtained by snapping or cutting off a leaf at the base and letting it dry for two or three days. Then the leaf with the cut surface is put into the ground as described for the shoot cuttings and forms roots there.

Grow from seed

The seeds of a Clusia should only germinate when they are very fresh and when you can provide a nice and warm location for the seed pots. A minimum temperature of between 21 and 25 °C is specified, there are hardly any upper limits in our climate. This is also why it is best to sow balsam apple seeds in late spring or early summer. They should germinate better if they are watered for 24 hours.

Sow the seeds in seed pots about 10cm in diameter or about 10cm apart in a seed tray prepared as follows:

• About 1 cm of fine grit or perlite on the bottom
• Fill up with the selected soil mixture up to just below the edge
• Cast on, evenly and continuously
• Spread some fine quartz sand on the surface of the earth
• Moisten the sand a little with an atomizer

You can now distribute the seeds that do not need to be covered with soil on this planting ground and cover them with a pane of glass or transparent plastic film. This increases the humidity and prevents the soil from drying out. Sowing containers from the trade usually have a hinged transparent cover.

• Location: Bright, warm, out of direct sunlight
• if the plant is by the window, cover it with some thin parchment paper to protect it from the sun

When the first seeds germinate, they need fresh air. Raise the glass/foil a little more often and clamp a pencil between the edge of the bowl and the lid. This is how you avoid fungal infestation. The seed pots are now best placed in light semi-shade, in an even but moderately moist substrate. There they can stay until they are big enough to prick (separately); the time has come when the young seedlings are easy to grasp. Then they are usually too close together. After pricking out, the small balsam apples can be cared for as described above for the large specimens.

The balsam apple and related mangosteen

The balsam apple family (Clusiaceae or Guttiferae) is a large family of plants whose members grow exclusively in tropical climes.

Apart from the “newcomer” Clusia, only the mangosteen is known to us, but because of its delicious fruit, not as a plant. The mangosteen is grown exclusively south of the 20th degree of latitude (from the southern tropic). From there it goes 5000 km north until you reach the Tropic of Cancer. Germany is a good 20 degrees of latitude further north.

The Clusia relative mangosteen is considered to be extremely climate-sensitive and generally mimosa. If the cultivation is successful (seeds only remain germinable for 3 to 5 weeks after harvest and only 5 days after removal from the fruit), the plant should not like all sorts of things, too little water, too much water, too little and too much nutrients, too much sun, too little sun, in winter anyway. If the Clusia is similarly bitchy, it probably isn’t worth growing from seeds. Dealing with a purchased plant should then be challenge enough.

If the culture succeeds here – with a lot of warmth and light – the typical “child of globalization” turns out to be a positive surprise in contrast to cheap plastic stuff – with which you can play nice jokes: If you use lettering or symbols If you scratch the thick-fleshed leaves, they will remain and grow with the plants, which is why the plant is also called the “autograph tree” in English-speaking countries.