Oleaster, Elaeagnus – care, cutting and varieties

Oleasters come in nearly a hundred different species within their family, the oleasteraceae. They usually grow as sturdy shrubs or smaller trees. More than half of the different Elaeagnus species are found exclusively in China, the others prefer warm temperate latitudes to subtropical areas.

Some species have thorns. Anyone who decides on an olive tree should do a little research in advance to find out which plant is suitable for their needs, because the individual species differ very little in terms of the shape of their leaves, but all the more so in some other properties. There are oleasters that reach a height of eight meters and lower varieties. As a rule, oleasters are about as wide as they are high. Some species are also hardy here and can be outdoors without any problems, while species that are not frost-resistant find a better place in a bucket or in a winter garden. In addition, oleasters are available that keep their leaves on the shoots over the winter (evergreen species).

• Narrow-leaved oleaster: growth height up to 7 metres, flowers May/June, fruits August to October (olive-shaped, silvery), deciduous, thorny, lanceolate leaves (silver-green).
• Silver willow (silverberry), growth height up to 5 metres, flowers May/June, fruits August to October (brown-silver), summer green, silvery leaves on both sides
• Evergreen oleaster (cross between thorny and large-leaved oleaster), stature height 2-3 metres, flowers September to November, fruits are rare (spring), evergreen in warm locations, otherwise deciduous, glossy dark green leaves
• Abundantly flowering oleaster (edible oleaster, red summer oleaster, long-stemmed oleaster, Japanese oleaster), 3-5 metres, flowers April/May, fruits August/September (cherry-shaped, red), deciduous, leaves dark green
• Thorny willow tree (stinging willow tree, variegated willow tree), height of growth 3-4 metres, flowers September/October, fruits April to June (brown-red, scaly), evergreen, slow-growing, thorny, glossy dark green or variegated leaves
• Coral willow tree (umbrella willow tree, umbelliferous willow tree), growth height of around 4 metres, flowers April/May, fruits August/September (pea-sized, red), green foliage

location

In nature, oleasters prefer places on the banks of rivers or lakes, forest edges or clearings. They are well suited as windbreaks or to strengthen embankments and are even planted as slip inhibitors on sandy surfaces such as dunes.

• Light requirement: high (full sun or light semi-shade)
• Soil: light, rather nutrient-poor and permeable to water (sand or clay)
• Also tolerates high salt concentrations in the soil
• pH value: slightly alkaline to slightly acidic (6.5-7.5)
• Little sensitive to air pollution.
• Windproof and heat resistant

maintenance

The undemanding olive tree does not require any special care for its care: occasional watering during the vegetation period and pruning when the wood has grown too large or is to be thinned out. In very hot or dry periods, the oleaster must be watered regularly and thoroughly. If the olive tree is in a bucket on the balcony or in the conservatory, 14-day fertilization with nitrogenous fertilizer is sufficient. In the field, a thin layer of compost can be worked into the soil in spring, which is usually enough to supply nutrients until autumn. While the willow tree tolerates short periods of drought well, it does not like waterlogging. However, if it is exposed to wet or dry conditions for a long time, it loses its leaves and tends to bare.

plant

Oleasters are not really difficult plants. They prefer fertile and, above all, well-drained soil. While the evergreen varieties can also cope with slightly heavier soil, deciduous species should preferably be planted in slightly drier and less nutrient-poor soil. Green-leaved oleasters like to stand in full sun, variegated variants (variegated leaves) are better off in very light penumbra. However, a gardener does not need to worry too much about the incidence of light at the location, the plants are generally very robust and fast-growing.

The best time for outdoor planting is in spring or autumn. Container plants can be potted all year round. If a young plant is to be kept in a pot, a container must be selected in which the roots have enough space.

• Minimum pot size: triple root ball.
• Create a drainage layer of gravel or expanded clay.
• Mix humus potting soil with sand (or clay).
• Root ball should be planted at the same level as before.
• Press the soil lightly.
• casting.

Planting outdoors follows the same principle. Instead of the pot, a planting hole is dug.

When planting, it should be remembered that the olive trees always face the sun. So if they are not in full sun as solitary plants, they tend to grow crookedly – always towards the sun. So if a semi-shady location is to become your new home, planting in a bucket is better so that you can rotate it a little if necessary.

particularities

With the help of bacteria with which they live in symbiosis, oleasters are able to convert atmospheric nitrogen and make it available to the plant. This happens in the nodule-like thickenings on the roots. In this way, the plants can survive on extremely nutrient-poor soils because they have their own fertilizer producers.

The fruits of many species are suitable for consumption. Therefore, oleasters are cultivated as a crop in some areas. Some varieties are also used as ornamental plants in gardens or parks.

The flowers of the willow spread a pleasant scent in the garden. They are among the ten most fragrant plants in our gardens. Some species form red fruits that taste sweet and sour, others bear nut-like fruits that can be eaten cooked or raw. The coral oleaster and the rich-flowered oleaster are mainly used as ornamental plants because of their decorative fruits. The thorny oleaster is available in many different leaf shades. They range from dark green to multiple shades within the yellow/green palette. It forms particularly decorative white flowers and later light red fruits.

To cut

Oleasteries tolerate both shaping and radical pruning very well. They are therefore ideal as hedge plants. Oleasters tend to develop long shoots. For this reason, young plants in particular should often be shortened at first so that they branch out better and the plant takes on a bushier appearance. If the oleaster should have grown too big, it can be cut back quite radically. For rejuvenation, older branches (near the ground) are pruned every few years so that young shoots can grow again. The best time to do this is in February or March, before the new leaves sprout.

• Cut young plants back by a third after about 2-3 years.
• Shorten old or dead shoots close to the ground.
• Remove any shoots that grow inwards
• Cut unbranched branches at least in half.
• After the winter, cut out all frost-damaged branches.

The more often the olive tree is pruned, the more it branches out. However, since the plant also has to grow, it should not be cut too often. In the beginning, an annual cut is necessary, later it is sufficient if you make a shaping cut every two to three years.

Propagation by seeds

The ripe seeds can be sown directly outdoors in autumn. If you prefer controlled germination in a pot, you should consider the following:

• Seeds need a cold period before germinating.
• To do this, mix the seeds in a plastic bag with wet sand.
• Store (stratify) at temperatures around four degrees for at least three months.
• For example in the fridge.
• Time: November/December
• After the cold period, remove from the refrigerator and sow.
• Substrate: potting soil or cactus soil.
• Moisten the substrate and put seeds in it.
• Cover lightly with soil.
• Use indoor greenhouse or cover pot with plastic bag.
• Germination temperature: at least 20 degrees (better 21-23 degrees)
• Location: warm but out of direct sunlight
• Check regularly that the soil is damp (not wet).
• If necessary, spray with the spray bottle.
• As soon as the seed has germinated and the small plant appears: bright location.
• Never expose freshly sprouted plants to direct sunlight.
• Danger of burns and drying out!
• If there are several seedlings, separate them (size about 3-5 centimeters)
• From now on, foil or bags are no longer needed to protect against evaporation.
• Keep substrate slightly moist.

When the plant has grown well, you can plant it outdoors next spring. However, it usually takes at least 3-5 years before it begins to bear fruit.

Propagation from cuttings

Propagation by cuttings is also very easy and can be done with both woody and half-ripe shoots. However, some species (such as coral oleaster) develop roots only very slowly. Sometimes it takes months to form them, and planting them outdoors requires a lot of patience, as this can take up to three years to complete. However, for many other species, propagation from cuttings is very simple and effective. To do this, cut woody or non-woody shoots (length at least 30 centimeters) in late spring. Remove the leaves from the lower third and plant in moist soil in a partially shaded location.

hedge plants

Due to its bushy form (low growth), the wintergreen oleaster can be used very well as a hedge plant. It is surprising that it is not used much more often in our gardens, because the cross between thorny and big-leaved oleaster has been represented in the domestic range for over 70 years. However, the willow tree is not really evergreen. In really cold winters, it can shed all its leaves. In the coming spring, however, it will sprout again and will then be fully leafy again. The trees tolerate the winter better if they stand against a wall or somewhat protected in the semi-shade. The wintergreen oleaster is very tolerant of pruning, but it is better to cut it with pruning shears than with hedge trimmers. The cut looks much looser. In addition, it is prevented

Planting distance for hedges: 80-100 centimetres

Winter

Anyone who plants their oleaginous willow in the garden should make sure that they choose a variety that is resistant to frost. All cold-sensitive plants should be planted in a bucket. In general, most oleasters tolerate temperatures down to -8 degrees without damage. Some species are resistant even to severe frosts. It is therefore better to ask the gardener in individual cases whether outdoor planting is advisable. Outdoor plants can be protected from frost in the root area with leaves or bark mulch.

Potted plants should be provided with a lot of light in the cold house at around eight degrees in the winter months or alternatively placed in a conservatory. The following applies here: the warmer the plant is, the more it has to be watered. This is especially important for evergreen plants, as they continue to evaporate water through their leaves. Leaf-shedding varieties, on the other hand, only need very little water in the cold season, but watering should never be omitted completely.

diseases and pests

The oleaster is a very robust plant in which diseases and pests are usually very rare. Only when their immune system is weakened (long periods of drought) does it become somewhat more susceptible. The oleaster is sensitive to waterlogging, which can lead to root rot.

Conclusion
When choosing an olive tree, the right plant for the location should always be selected from the various species. There are evergreen and deciduous species, hardy or frost-sensitive, different leaf and fruit colors. In addition to well-drained soil, oleiferous pastures require little fertilizer and occasional watering. Because these are fast-growing shrubs that tend to become sparse, an occasional pruning will help create more side shoots. Oleasters can be pruned at will, even radical pruning doesn’t bother them.