The bitter orange is a robust plant with a rustic charm and an abundance of flowers. But she needs a certain amount of care. By the way: The bitter orange is also very easy to propagate.
The bitter orange (Poncirus trifoliata) is the only representative of the genus Poncirus and belongs to the rue family. The trefoil lemon should not be confused with the closely related citrus fruit, also known as the bitter orange, a cross between a tangerine and a grapefruit. Bitter oranges grow about three to four meters high and have one big advantage - the hobby gardener can bring Mediterranean charm to the garden even in regions with a less mild climate, because the bitter orange is hardy, robust and easy to care for.
Plant Description
While bitter oranges can grow up to ten meters high, the three-leaf lemon only reaches a maximum of four meters in height. The shrub has a green bark, flattened twigs and noticeably strong thorns. The leaves are in three parts, which is why it is called the three-leaf lemon. Already in autumn the bitter orange lays 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 fall coloration.
Distribution 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 question the winter hardiness of the bitter orange. Due to its natural occurrence in the Himalayas, however, the plant is sufficiently cold-tested and survives the winter in German gardens.
Bitter oranges reached Europe via the Orient and North Africa as early as the 10th century. A first cultivation has been handed down from Spain in the 11th century. Poncirus trifoliata has remained exotic in our latitudes to this day. Completely wrong, as it is the most frost-hardy citrus plant in Europe. In addition, bitter oranges are a good basis for grafting citrus plants.
When does the bitter orange bloom?
The first flowers appearoften as early as April and thus before the leaves sprout. 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 following period, the yellowing sets in.
The fruits are not enjoyable but edible. They contain a lot of seeds and only a little pulp. In any case, the ornamental value is higher than the utility value of the 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, the bitter orange actually refers to two different plants.
» Bitter orange (Poncirus trifoliata)
- Rhombus plant, separate genus Poncirus
- hardy
- deciduous
- Growth height up to four meters
- Fruit edible but of no economic importance
» bitter orange/bitter orange
- Rhombus, Citrus
- not hardy
- evergreen
- Growth height up to ten meters
- Fruit edible, versatile use
Plant bitter oranges
Robust and easy to cultivate, the bitter orange invites you to bring southern flair into your home garden. You can now read about what needs to be considered when planting.
❍ Location:
A warm and sunny location should be found for the bitter orange. The rue family feels particularly at home in a sheltered spot, not far from a south-facing house wall.
» Tip: The group planting of the bitter orange can also be laid out in the form of a hedge. The strong thorns will make it difficult for intruders.
Planted alone, the trefoil lemon does well in conjunction with lavender, squill or other blue or purple flowering flowers and perennials.
The ideal location in keywords:
- light
- warm
- sunny
- protected
❍ Substrate:
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 adding coarse sand. Bitter oranges do not tolerate waterlogging, so the liquid should always be able to drain off easily. A slightly acidic soil with a low lime content is ideal for the plant.
The right substrate in keywords:
- loose
- permeable
- slightly sour
- limescale
❍ Planting Instructions:
❶ Select location
❷ Loosen, clean, upgrade soil
❸ Dig planting hole
❹ Water bitter orange
❺ Insert plant
❻ Fill up the substrate
❼ Water the plant well
Spring is the best time to plant the three-leaf lemon. This gives the plants enough time to grow vigorously and prepare for winter. The soil should be well loosened. Barren soils can be upgraded with compost. The incorporation of coarse sand protects against waterlogging. The planting hole should be about twice the width of the root ball. During the first few weeks after planting, the bitter orange needs plenty of water.
Cultivate the bitter orange in a bucket
Keeping the plants in tubs is just as easy. If the three-leaf lemon is placed in a planter, it can also bring Mediterranean flair to the balcony or terrace. Potted plants need water regularly and should be fertilized during the growth phase. To prevent waterlogging, a drainage made of gravel or potsherds should be placed on the bottom of the container.
Repot bitter oranges
The bitter orange grows quite quickly, but then shows its relationship to citrus plants by growing quite slowly. Repotting will only be necessary every two to three years.
» Tip: If the plant shows stunted growth, the root ball has penetrated the plant pot and the substrate is used up or waterlogging has occurred, the pot should be repotted immediately.
The new cachepot should be a few centimeters larger than its predecessor. It is also important to ensure that there are sufficient drainage holes so that the irrigation water does not accumulate in the vessel.
How to properly care for the bitter orange
Casting:
During the growth phase, the bitter oranges are poured abundantly. A bit of sensitivity is required so that the fine roots are not damaged by incorrect watering behavior. The root ball should not dry out. It is important to avoid waterlogging in any case. It should also be watered preferably with rainwater. Tap water has a high lime content, which is less beneficial for the plant.
» Tip: Curled leaves indicate a problem with the water balance. Either too little or too much was watered.
Fertilize:
During the growing season, thePlant liquid fertilizer weekly. A citrus fertilizer can be used for this. Make sure you have a high nitrogen content. Furthermore, sufficient trace elements such as iron, copper, magnesium or zinc should be included.
Pruning:
The pruning of the bitter orange should not be done too radically, because the plants only grow slowly. Regularly removing dead branches will maintain the decorative appearance of the plant. The crown should be trimmed and kept in shape with a training cut.
» Tip: It is difficult for the plant to recover from radical pruning.
Spring is the right time for pruning. If you want to shape the crown, you can use the scissors again in autumn.
Pests and Diseases:
If care mistakes are avoided, the bitter orange is a robust and hardy plant that rarely gets sick. Nevertheless, the close relationship to citrus plants also makes the trefoil lemon vulnerable to pests that target citrus plants.
Includes:
- spider mites
- Citrus Fleas
- Black Flies
- scale insects
- Aphids
» Spider mites
These are tiny arachnids that settle on the underside of leaves and are therefore often overlooked. When the tiny creatures, which are about one millimeter in size, begin to suck the plant sap from the leaves, this also becomes visible on the leaf surface. There are initially silver-grey shimmering spots that later turn gray. An infestation can also be identified on the fine webs. These become particularly visible when the leaf orange is given a shower with the hose or the plant sprayer.
What to do?
As a preventative measure, the 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 required to remove all infestation.
» Citrus Fleas
The leaf fleas belong to the plant lice, are about three millimeters in size and move by jumping. Fleas have natural enemies with the fungus Entomophthore sphaerosperma, ladybirds, spiders or gall midges. Fighting fleas is generally difficult and usually requires the use of chemicals.
» Blackflies
When watering, an infestation with fungus gnats is easily recognizable because the insects flyfrom the substrate. The damage appears rather minor, but the infestation is annoying. One danger is blackfly for young plants. The larvae of the pest feed on the tender roots, which young plants usually do not survive.
What to do?
The plants should be transplanted. If a complete soil exchange takes place, the danger should be averted. The pests are prevented from laying their eggs if coarse sand is spread on the substrate around the plant.
» Scale insects
Often it's not the scale insects themselves that catch the eye. If the bitter orange seems 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 excretions of the scale insect. Scale insects are well camouflaged but can be spotted with the naked eye. Prolonged drought attracts scale insects. Therefore, the plants should be sprayed more frequently.
» Aphids
Especially young bitter oranges are attacked by aphids. The tender shoots and buds are considered the favorite food of the pests. The problem is not just the aphids alone, their excrement leaves a sticky film on the plant, which in turn attracts other insects or promotes fungal growth. A shower with soapy water helps against aphids. Ladybugs or lacewings are natural predators.
Propagation:
Propagation by seeds is common. The three-leaf lemon contains plenty of seeds, which are harvested and dried in autumn. In the spring you start growing the plants on the windowsill.
Growing by seeds step by step
❶ Prepare the seed tray
❷ Fill the seed tray with loose substrate
❸ Plant the seeds about a centimeter deep
❹ Keep the soil only slightly moist
❺ Seed seed tray with provided with a lid made of plastic or glass
❻ no warm, bright place
❼ germination after a few weeks
Once the plants have reached a size of about eight centimetres, they are placed in individual planters and initially cultivated indoors.
» Tip: When transplanting, the original core should not be removed. It still contains important nutrients.
Propagation by cuttings
❶ Cut the cutting
❷ Defoliate the cutting and remove the buds
❸ Dip the cutting in rooting powder
❹ Place the cutting in a pot filled with potting soil
❺ Plant the cutting place in a warm and bright place
❻ cover offPlastic or glass promotes budding
❼ Keep cuttings evenly moist
In this phase, the bitter oranges grow quite quickly and after they have sprouted, it is time to place 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 placed outdoors.
Hiberation:
Citrusy and frost don't seem made for each other. The three-leaf lemon is a welcome exception and is absolutely hardy down to temperatures of -25 degrees.
There are some exceptions though. Young plants are more susceptible to frost. The winter sun can cause frost cracks. The bitter orange in the tub is preferably overwintered in the house. This can be done in a frost-free place. The three-leaf lemon does not necessarily have to be bright because there are no leaves on the plant in winter. The soil should also be kept evenly moist in winter, but not too wet.
Cultivate the bitter orange as a bonsai
The bitter orange is an attractive bonsai plant that is quite easy to grow. In the field, the bonsai needs a sunny and sheltered location. It should preferably be watered with rainwater. Tap water diluted with distilled water can also be used. The soil is allowed to dry out a little between the individual waterings. Waterlogging must be avoided urgently. Growth can be supported with liquid fertilizer for bonsai plants.
The bonsai is cut after flowering. All unneeded shoots are removed. All common forms can be bred out. The semi-cascade or upright growth is particularly popular. The bitter oranges can be wired from spring to autumn. Care must be taken to ensure that the wire does not grow in. Bitter oranges need to be repotted as a bonsai plant about every three years.