The bitter orange is a robust plant with a rustic charm and a rich floral display. But for that she needs a certain amount of care. Incidentally, the bitter orange can also be easily propagated.© Dario Sabljak - Fotolia.com
The bitter orange (Poncirus trifoliata) is the only representative of the genus Poncirus and belongs to the diamond family. The three-leaf lemon is not to be confused with the closely related citrus fruit, also called bitter orange, a cross between a tangerine and grapefruit. Bitter oranges grow about three to four meters high and have a big advantage - the hobby gardener can bring Mediterranean charm into the garden even in regions with less mild climate, because the bitter orange is hardy, robust and easy to care for.
While bitter orange can grow up to ten meters high, the three-leaf lemon only reaches a maximum height of four meters. The shrub has a green bark, flattened branches and strikingly strong thorns. The leaves are three-part, which leads to the term three-leaf lemon. Already in autumn, the bitter orange creates the buds for the next year. In contrast to the bitter orange, the bitter orange is not evergreen, but sheds its leaves. The leaf fall is accompanied by a pretty, yellow-orange autumn color.
Dissemination and benefits
The bitter orange is native to northern China and Japan. In its wild form, the three-leaf lemon mainly grows as a hedge. Some hobby gardeners may be skeptical and doubt the hardiness of bitter orange. Due to its natural occurrence in the Himalayas, however, the plant has been sufficiently cold-tested and survives the winter in German gardens.
As early as the 10th century, bitter oranges reached Europe via the Orient and North Africa. The first cultivation is from 11th century Spain. Poncirus trifoliata has remained an exotic species in our latitudes to this day. Completely wrong, because it is the hardiest citrus-like plant in Europe. In addition, bitter oranges are a good finishing base for citrus plants.
When does the bitter orange bloom?
The first flowers often appear as early as April and thus before the leaves shoot. The flowers have a diameter of about four centimeters and show the close relationship to the bitter orange. Each flower has five petals and yellow stamens. When the bitter orange is in bloom, it is surrounded by a beguiling orange scent. The fruits initially appear green and are surrounded by a furry down. In the period that followed, the yellowing started.
The fruits are not enjoyable but edible. They contain a lot of seeds and only a little pulp. The decorative value is in any case higher than the useful value of bitter oranges.
Bitter orange times two
Without wanting to cause confusion, here is a brief outline of the types of bitter orange. As already mentioned, bitter orange actually means two different plants.
»Bitter orange (Poncirus trifoliata)
- Diamond family, own genus Poncirus
- Height up to four meters
- Fruit edible but of no economic importance
»Bitter orange / bitter orange
- Lozenge, citrus
- not hardy
- Height up to ten meters
- Edible fruit, versatile use
Plant bitter oranges
Robust and easy to cultivate, the bitter orange is an invitation to bring southern flair to your home garden. You can now read what needs to be considered when planting.
A warm and sunny location should be found for the bitter orange. The lozenge plants feel particularly comfortable in a protected location, not far from a south-facing house wall.
" Tip: The group planting of bitter orange can also be created in the form of a hedge. The strong thorns will make it difficult for intruders.
When planted alone, the three-leaf lemon works well in conjunction with lavender, blue stars or other blue or violet flowers and perennials.
The ideal location in brief:
The bitter orange makes no special demands on the soil. Good permeability of the substrate is advantageous. This can be achieved in the bed by mixing in coarse sand. Bitter oranges do not tolerate waterlogging, so the liquid should always drain off easily. A weakly acidic soil with a low lime content is ideal for the plant.
The right substrate in brief:
- slightly acidic
❍ Planting instructions:
❶ Select location
❷ Loosen, clean and upgrade the floor
❸ Dig out the planting hole
❹ Water bitter orange
Einsetzen Insert the plant
❻ Fill up the substrate
Ießen Water the plant well
The best time to plant the three-leaf lemon is in spring. Then the plants get enough time to grow vigorously and prepare for winter. The soil should be loosened up well. Poor soils can be upgraded with compost. The incorporation of coarse sand protects against waterlogging. The planting hole should be dug out about twice the width of the root ball. The bitter orange needs plenty of water during the first few weeks after planting.
Cultivate the bitter orange in the bucket
It is also easy to keep the plants in containers. If the three-leaf lemon is placed in a planter, it can also bring Mediterranean flair to the balcony or terrace. Container plants regularly need water and should be fertilized during the growth phase. So that there is no waterlogging, a drainage of gravel or shards of clay should be placed on the bottom of the vessel.
Repot bitter oranges
The bitter orange grows very quickly, but then shows its relationship to the citrus plants through a rather slow growth. Repotting will only be necessary every two to three years.
" Tip: If the plant indicates growth disorders, the root ball has penetrated the plant pot and the substrate has been used up or if there is waterlogging, it should be repotted immediately.
The new planter should be chosen a few centimeters larger than its predecessor. Ensure that there are sufficient drainage holes so that the irrigation water does not build up in the vessel.
How to properly care for bitter orange© josevgluis - Fotolia.com
In the growth phase, the bitter oranges are watered abundantly. A little tact is required so that the fine roots are not damaged by incorrect pouring behavior. The root ball should not dry out. Waterlogging must be avoided in any case. It should also preferably be poured with rainwater. Tap water has a high lime content, which the plant gets less well.
" Tip: Rolled up leaves indicate a problem with the water balance. Either too little or too much was poured.
During the growing season, the plants receive liquid fertilizers every week. A citrus fertilizer can be used here. Pay attention to a high proportion of nitrogen. Sufficient trace elements such as iron, copper, magnesium or zinc should also be included.
The bitter orange should not be cut too radically because the plants grow slowly. Regularly removing dead branches maintains the decorative appearance of the plant. The crown should be shaped and kept in shape with an educational cut.
" Tip: The plant can hardly recover from a radical pruning.
The right time for cutting measures is spring. If the crown is to be shaped, scissors can be used again in autumn.
Pests and diseases:
If care errors are avoided, the bitter orange is a robust and resistant plant that rarely ailments. Nevertheless, the close relationship to the citrus plants makes the three-leaf lemon also vulnerable to pests that target citrus plants.
- spider mites
- Citrus psyllids
- Black flies
- Scale insects
These are tiny arachnids that settle on the undersides of the leaves and are therefore often overlooked. When the tiny little ones, about one millimeter in size, start sucking the plant sap from the leaves, this is also visible on the leaf surface. There are initially silver-gray shimmering spots that later turn gray. An infestation can also be identified on the fine webs. These are particularly clearly visible when the leaf orange receives a shower with the hose or the plant sprayer.
What should I do?
As a preventative measure, plants should be sprayed frequently, especially if there is a long period of drought. Spraying with soapy water has also proven effective against spider mites. Frequent spraying is necessary so that the entire infestation can be eliminated.
»Citrus leaf fleas
The leaf fleas are plant lice, are about three millimeters in size and move leaping. Leaf fleas have natural enemies with the fungus Entomophthore sphaerosperma, ladybirds, spiders or gall mosquitoes. Fighting fleas is generally difficult and usually requires the use of chemical agents.
An infestation with black gnats is easy to recognize when watering, because the insects fly out of the substrate. The damage appears rather small, but the infestation is annoying. The black fly is a danger for young plants. The pests' larvae feed on the delicate roots, which young plants usually do not survive.
What should I do?
The plants should be transplanted. If there is a complete exchange of soil, the danger should be averted. The pests are prevented from laying eggs if coarse sand is sprinkled on the substrate around the plant.
Often it is not the scale insects themselves that catch the eye. If the bitter orange appears to be in the general interest of the ants, the scale insects are usually not far away, because ants are attracted to the honeydew, the excrement of the scale insect. Scale insects are well camouflaged, but can be seen with the naked eye. Prolonged drought attracts scale insects. Therefore, the plants should be sprayed more often.
Aphids in particular attack young bitter oranges. The tender shoots and buds are considered the favorite food of the pests. The problem is not just the aphids alone, whose excretions leave a sticky film on the plant, which in turn attracts other insects or promotes fungal attack. A shower with soapy water helps against aphids. Ladybugs or lacewings are considered natural predators.
Propagation by seeds is common. The three-leaf lemon contains plenty of seeds, which are harvested and dried in autumn. In spring you start growing the plants on the windowsill.
Grown by seeds step by step
❶ Prepare the growing tray
❷ Fill the culture vessel with a loose substrate
Einsetzen Insert seeds about one centimeter deep
❹ Keep the floor slightly damp
❺ Provide a growing bowl with a lid made of plastic or glass
❻ Warm, bright stand is missing
❼ Germination after a few weeks
When the plants have reached a size of about eight centimeters, they are placed in individual planters and initially cultivated further in the room.
" Tip: The original seed core should not be removed when transplanting. It still contains important nutrients.
Propagation by cuttings
❶ Cut the cutting
❷ Defoliate cuttings and remove buds
❸ Dip the cuttings in the rooting powder
❹ Place the cuttings in the plant pot filled with growing soil
❺ Place the cutting in a warm and bright location
❻ Plastic or glass cover promotes sprouting
❼ Keep the cutting evenly moist
In this phase the bitter oranges grow quite quickly and after the budding it is time to put the plant in a larger planter. If garden soil is mixed with sand, a permeable substrate is found. If the plant has developed well after a few weeks, it can be put outdoors.
Citrus-like plants and frost don't seem intended for each other. The three-leaf lemon is a welcome exception here and is absolutely hardy up to temperatures of -25 degrees.
However, there are a few exceptions. Young plants are more susceptible to frost. The winter sun can cause frost cracks. The bitter orange in the bucket is preferably hibernated indoors. This can be done in a frost-free place. The three-leaf lemon does not have to be bright, since there are no leaves on the plant in winter. The floor should be kept moist even in winter, but not too wet.
Cultivate bitter orange as bonsai
The bitter orange is an attractive bonsai plant that is easy to cultivate. In the open, the bonsai needs a sunny and protected location. It should preferably be poured with rainwater. Tap water that has been diluted with distilled water can also be used. The soil is allowed to dry a little between the individual waterings. Waterlogging must be avoided urgently. The growth can be supported with liquid fertilizers for bonsai plants.
The bonsai is cut after flowering. All unnecessary shoots are removed. All common forms can be grown. The semi-cascade or upright growth are particularly popular. The bitter oranges can be wired from spring to autumn. Make sure that the wire does not wax in. Bitter oranges have to be repotted as bonsai plants about every three years.