Olive tree care in Germany

The olive tree (Olea europaea) is a medium-sized, gnarled tree of the olive family. The evergreen tree with the small, leathery leaves is not native to us. It is actually too cool for the plant in Germany, but it is also one of our popular plants that exude a touch of Mediterranean flair. Better than in the garden, however, the real olive tree is kept in a bucket in a conservatory or in summer on the terrace or balcony.

Location

Olea europaea is one of the children of the sun, which is only found in winter-warm regions. The brighter and warmer the tree is, the better it will grow and thrive. Since this is not necessarily possible outdoors in Germany, it is usually cultivated as a container plant.

• full sun in summer
• as warm as possible
• tolerates heat
• does not tolerate drafts

Cultivation in the bucket

An olive tree prefers mild temperatures all year round and does not tolerate severe frosts. Since there is a certain risk that the plant will not survive the cold season outdoors, there are actually certain restrictions on its cultivation. In cold regions, year-round outdoor living is impossible. The advantage of planting in a tub is therefore obvious: the olive tree can easily be transported to a frost-free place.

However, if you want to grow the tree as a houseplant, it should be said that the olive tree does not find good conditions in the apartment in the long term. Therefore, the plant must be planted outdoors in the warm season, be it on a balcony or terrace or planted together with the tub in the garden soil.

• Dwarf varieties are particularly suitable
• Pot size should roughly match the crown size

substrate

When planting and also when repotting an olive tree, you should only use very high-quality substrates. Good potting soil is characterized by coarse-grained parts, such as gravel, lava granules or expanded clay. They are loose and allow both water and air to pass through very well. A proportion of humus is also necessary for better storage of water and nutrients, but this should not be too high when cultivating olive trees.

• high mineral content (sand, gravel, expanded clay etc.)
• low humus content
• Cactus soil mixed with clay
• Substrates for Mediterranean plants
• sandy-loamy soil mixture
• citrus potting soil

Stay outdoors in summer

Should you buy an olive tree in the cold season or grow a plant yourself from a cutting over the winter wait until the danger of late frosts has passed before moving the plant onto the balcony or terrace in spring place. Also, help your olive to acclimatize by first placing it in a sheltered spot in partial shade. Gradually it tolerates more sunshine and wind.

After about 10 days you can put the olive tree in its final place in full sun. The wood then remains outside until the first frosts. Before it comes back to the apartment in the fall, this process must go in reverse order. Slowly move the bucket to a slightly more shady location. Within 10 days, the plant is then ready to adapt to the reduced light levels indoors.

repot

If your olive tree came in a plastic pot when you bought it, turn it upside down and gently pull on the bottom of the trunk to free the root ball. The old pot often has very strong roots, which is why it is almost always necessary to repot the tree for the first time immediately after purchase. Young plants should be checked at least twice a year to see whether there is still enough space for the roots in the planter. In the case of older olive trees, it is sufficient to check them before the new growing season in spring (from March).

• preferably use pots made of terracotta (clay).
• must contain drainage holes
• use the next larger pot size
• use tall rather than wide vessels (root grows deep)
• Pull the roots apart with your hands and loosen them up
• first pour in a layer of drainage (clay, grit).
• fill in a suitable substrate
• insert bales
• fill up with good quality substrate

Make sure the tree is no deeper in the ground than it was before, and leave at least an inch of space between the soil and the edge of the tub. So you still have room to pour without the water overflowing. The pot should be placed on a suitable saucer that catches excess water well.

Repot mature trees

If the largest possible pot size has already been reached, the wood should never be left to its own devices. In this case, the roots will eventually fill the entire plant pot and have displaced all the soil. The tree inevitably begins to show signs of deficiency and eventually withers away. To prevent this, the plant should be removed from the plant pot every two years at the latest.

• cut off about 1 to 2 cm of the root network around the ball with a knife
• both on the side and below
• loosen the remaining bale by hand
• Thoroughly clean the planter
• Fill drainage
• fill in a little fresh substrate
• insert bales
• Fill in gaps with substrate
• water lightly

Removing parts of the root mass creates an imbalance between water supply and evaporation from the leaves. So that there are no bottlenecks in the supply of the olive tree, the crown of the tree should be pruned carefully to the same extent as with the root cut. After repotting, place the plant in a slightly more shady position than before and carefully monitor the humidity of the root ball to prevent a lack of water.

flower and fruit

It is very unlikely that a warm wintered olive tree will set flowers or fruit. In order to stimulate flowering (between May and June), the plant needs a drop in temperature to below 10 degrees Celsius over a period of at least two months. If you have the opportunity to place your tree in a cool greenhouse or an unheated conservatory, this could be very beneficial for flowering. While some olives are self-fertile, if you cultivate a second tree, you will get a larger harvest because of cross-pollination. Self-fertile varieties include:

• 'Aglandou'
• 'Cailletier'
• 'frantoio'
• 'Leccino'

Planting an olive tree in the garden

Planting an olive tree in your own garden is also possible in Germany. However, olive tree owners are often afraid of doing something wrong, because the trees originally come from the Mediterranean region and are considered to be very sensitive. However, if you live in a mild region of Germany and follow a few care tips, you can still plant such a tree directly in your garden. When purchasing, be sure to purchase a slightly more frost-tolerant variety.

• preferably choose a young plant
• cultivate them as a container plant for the first five to seven years
• in the autumn as late as possible into the winter quarters
• always spend the winter cool and light (only just over 0 degrees), this serves to acclimate
• suitable varieties: 'Hojiblanca', 'Manzanilla' or 'Picual'
• the tree can hardly cope with getting used to it
• Planting hole: at least twice the ball size
• Planting distance: at least 5 m

Make sure that the olive tree gets a lot of space. Five meters distance to the next larger tree is a minimum for normal sized olive tree species. The same applies to the undergrowth: It is better to avoid other plants in the root area of ​​the tree so that the roots do not grow into each other.

Floor

In order for the olive tree to be able to grow well and vigorously outdoors, it is important to have soil that is well permeable to water, because the Mediterranean plant does not tolerate waterlogging at all. In addition, the soil must not offer the fine roots much resistance, so that they can spread without too much effort. In addition, the wood prefers a low humus content.

• good water permeability
• relaxed
• profound
• only slightly humorous

Care

Caring for an olive tree is not particularly difficult. The right location and a good substrate are much more important. If both conditions are optimal, the wood needs little attention to be able to grow healthy and strong.

Pour

When caring for the olive tree, watering is the most important factor. The tree needs a lot of water, especially in summer in a sunny spot. It is best to completely soak the bale until the water runs out of the drainage hole again. Excess water is poured away. Then wait until the substrate has dried a little before watering the next time. While well-established outdoor specimens must also tolerate prolonged droughts and intense heat Potted plants should be watered a little more often - this is especially true for freshly repotted/planted olive trees and also young plants. Olive trees grow very slowly, so avoid excessive watering – especially in autumn and winter.

Trees, which are free to spread freely, have their roots deep into the garden soil, which is often wetter than near-ground layers. Nevertheless, the trees need balanced watering. For planted specimens, therefore, make sure that the water does not simply run off the surface. This can be done either with very slow (fine or drop by drop) watering. Alternatively, a pouring rim can keep the water in the root area.

Fertilize

Since there are no special fertilizers for olive trees, you can use ordinary fertilizers for Mediterranean plants or potted plants. Normally slow-release fertilizers are advisable in March and June. Olive trees do not require high levels of nutrients, so outdoor plants usually get by with some compost in the spring.

Cut

The real olive tree grows very slowly, so it does not have to be cut very often. In the care of the tree, the cut only has the function of educating and maintaining the wood. Training is about achieving a beautiful crown shape, while maintenance is simply removing diseased and dead branches. If an olive tree becomes too big, you can make smaller cuts all year round. For more radical pruning, spring is recommended, i.e. at the end of the dormant period. In this way, the plant can sprout freshly in the new growth period.

• Cut off any dead or diseased shoots
• remove one of two crossing shoots
• Cut inward growing branches at the base
• shorten long, unbranched branches
• Thin out the crown regularly by about 10%

If the crown becomes too dense over time, the wood will bare from below and from the inside. In addition, the air in the dense crown can only circulate poorly, making the tree susceptible to various diseases.

Overwinter potted plants

If the first frosts occur outdoors, the olive tree must be moved to a sheltered, warmer location. Here, too, make sure that you slowly get used to the changed lighting conditions. Choose a spot for your olive tree in the house or apartment that faces south and gets at least 6 hours of sun a day. Olive trees do not lose their leaves in autumn, so they need a lot of sunlight even in the cold season. For flowering and to prevent pest infestation, the tree should preferably be cool.

• set up very bright
• optimal temperature: 5-10 degrees
• at higher temperatures, an additional plant light is necessary
• continue to water, but a little more cautiously than in summer
• the lower the temperature, the less watering is required

Outdoor plants overwinter

In Central Europe, overwintering planted olive trees is a bit more complicated than in their homeland. The first frost damage can already be expected from permanent temperatures of -5 degrees. This means that the tree can only be cultivated as a container plant in cold regions. Planting out is possible in wine-growing areas, but great importance is attached to good winter protection.

• Pile up soil in the root area well with mulch, leaves or sticks
• attach winter protection fleece (crown area) in case of severe frost
• must be translucent
• may only be used during prolonged periods of frost
• then remove again
• otherwise the moisture cannot evaporate and illnesses occur

multiply

Although olive trees can be propagated by seeds or cuttings, propagation by cuttings is more promising. However, this requires a lot of heat.

cuttings

Select one or more young, not yet lignified shoot tips.

• Length: 10cm
• The cutting edge should be slanted
• remove the lower leaves
• Fill a small plant pot with cactus or potting soil and moisten
• Tuck in one-third of the offshoots
• Press the soil lightly all around
• place in a bright, warm location (without midday sun)
• keep moist but not wet
• Temperature: 20-25 degrees

seed

Somewhat more complex, but by no means impossible, is propagation via seeds. To do this, use the cores of fresh, ripe fruit or, alternatively, seeds from specialist retailers.

• remove pulp
• Soak the core in lukewarm water for 24 hours
• Plant in moist cactus soil
• Planting depth: 1 cm
• Place pot in freezer bag and seal
• Temperature: at least 20 degrees

diseases and pests

Like any plant, an olive can be attacked by fungi, viruses, bacteria and various other pests. This is usually the case when the wood is severely weakened. This can happen if the location or care is not optimal.

waterlogging

Too much watering (waterlogging) causes root rot. If the leaves of the tree change color and eventually fall off, this can be a possible consequence of waterlogging. Therefore, make sure you have a good water balance and fill the pot with a thick drainage layer before potting the plant. In the event of illness, only the immediate removal of putrid soil and roots will help.

lack of water

A similar pattern of damage as with waterlogging can be seen in the case of a lack of water. It must be clarified in each individual case whether the substrate is too damp or too wet.

Conclusion

There are various ways of cultivating an olive tree here too. In most cases, planting in a pot is advisable because of the lack of winter hardiness. The tree can only be planted in mild wine-growing areas. The following applies to the location: sun, sun, sun. The brighter and warmer, the better. Do not water the olive too often and it is best to ensure that it is kept cool and bright over the winter. With good care, an olive tree can become very old.

Learn more about potted plants