In this country too, lemon trees are welcome guests on balconies and terraces. They spread a pleasant atmosphere. In winter, however, they need appropriate winter quarters. Sometimes you can get sticky leaves here.

In a nutshell

  • sticky drops on the lemon tree often during the winter break
  • usually occurring on the underside of leaves, shoots and branches
  • The culprits are shield lice, mealybugs and mealybugs
  • in the case of a massive infestation, the plant is permanently damaged
  • Combat mechanically or with soapy water and oil

Various causes

In summer, the lemon tree feels very comfortable outdoors. However, it is not hardy in our latitudes and therefore needs a frost-free winter quarters. Sometimes it can happen very quickly that sticky leaves appear during the hibernation. There is not only one reason for this, but there are various possibilities such as:

  • too warm and dark location
  • too dry air
  • Nutrient deficiency or excess
  • wrong watering
  • no air circulation

The lemon tree usually "sticks" during the winter period, but sticky leaves can also appear during the growing season if the wrong location is chosen.

Culprit: scale insect

Typically, sticky leaves are primarily caused by scale insects. These suck the plant sap and then excrete sugary excrement, the so-called honeydew. Since this contains a high sugar content, sticky leaves occur. Not only these are glued, the immediate surroundings are also glued. Scale insects are able to throw their droppings up to 15 centimeters away. So it can happen that the floor sticks.

identify scale insects

Scale insects are relatively small, but can still be seen with the naked eye. As a rule, they are located along the pathways on the underside of the leaf, but also on smaller shoots and branches. Here the bark is still relatively soft and the sap can be easily sucked out. Special features are:

  • have oval to rounded brown-black shields
  • Size approximately 2 x 3mm
  • females lay eggs under shield
  • Females often immobile
  • The white larvae hatch from July
  • Larvae are mobile
  • Likes to attack leaves and shoots of neighboring plants
  • only female animals suck plant sap
  • release of poisonous saliva
  • Plant tissue is destroyed
  • male specimens harmless
  • have no mouthparts
  • are often winged

A few more comments on mealybugs and mealybugs. They also damage the lemon tree by sucking out the sap. They are mainly found in the leaf axils and forks of the twigs and branches, sometimes also on the underside of the leaf. They are 3 to 4 millimeters in size and white to pink in color. Furthermore, the red spider mite can damage plants that are cultivated indoors or plants that have been wintered too warm and dark. They are almost 0.5 to 1.0 millimeters in size and sit along the pathways on the underside of the leaf, where they also suck out the plant sap. Fine, white webs in the leaf axils, on the undersides of the leaves and on the tips of the shoots are typical. Control takes place in exactly the same way as with lice.

Tip: If the soil is sticky in the immediate vicinity of the lemon tree and more ants appear, these are the first signs of an infestation with scale insects, especially outdoors. They love the lice excretions and feed and protect them.

Measures against lice

When fighting lice, especially scale insects, chemical agents should be avoided if possible. These can sometimes damage the lemon tree itself and are also dangerous for the environment. There are a number of ways to get rid of scale insects on lemon trees.

Mechanical combat

This is probably the easiest way to combat the cause. All you need is a water hose with a nozzle and a toothbrush. The procedure is as follows:

  • Lay the plant on its side
  • Lice must not get into potting soil
  • alternatively cover the pot and soil with a plastic bag
  • Rinse the plant with a strong jet of water
  • either use a nozzle or
  • Squeeze the end of the hose
  • then use the toothbrush
  • gently scrub off any leaves and twigs
  • Always move the brush at right angles to the branch to be treated
  • then shower the lemon tree again
  • constant control in the following days
  • repeat the procedure if necessary

Notice: Smaller lemon trees can simply be soaked upside down in a bucket filled with lukewarm water for a few hours.

soapy water

Using soapy water can also help to combat lice and sticky leaves. This requires:

  • 1 teaspoon liquid or grated curd soap
  • 1 liter of lukewarm water
  • a spray bottle

Everything must be mixed well. It is important that the soap has dissolved properly. The treatment can then take place:

  • It is best to lay the plant down
  • then spray well with the lye
  • should act for a few hours
  • preferably overnight
  • shower thoroughly with clear water the following day
  • Repeat procedure after a few days
  • thereby destroying all eggs and hatched larvae

However, using soapy water can become a bit of a concern when pre-existing fruit is intended for consumption.

Tip: A cotton swab soaked in alcohol can help if the animal is found alone. The lice are simply coated with it.

rapeseed oil

Rapeseed oil can also be a good help in repelling lice. As with the use of soapy water, the airways are blocked and the animals suffocate. In addition, the leaves become slippery and the lice no longer have a foothold. However, before treatment, a larger stack of paper should be laid out to avoid soiling the floor. Then it can go:

  • Make a mixture of 30% rapeseed oil and 70% water
  • spray plant
  • leave on for at least 3 hours
  • then rinse off with clear water
  • repeat treatment if necessary

Notice: Remaining oily residues are disadvantageous in the treatment. However, this gives the leaves a nice shine.

frequently asked Questions

Can you prevent a scale insect infestation?

Prevention is always better than cure. The location must be bright, sunny and sheltered from the wind. A humus-rich, slightly acidic, well-drained soil such as special citrus soil is good. Maintenance also plays a major role. Watering is rare but penetrating, daily on hot days. The top layer of soil must be dry, use lime-free water. Fertilization is necessary every 14 days in spring and weekly from June to September. Frequent spraying of the plant is also helpful.

Does hibernation have an impact on scale insect infestation?

Proper hibernation can prevent infestation. Temperatures between 3 and 13 °C and not too bright are ideal. The colder the lemon tree is, the darker it has to be. The root ball should never dry out completely. At temperatures above 15 °C, spraying with lukewarm water is helpful.

Do chemical agents help against scale insects?

In the case of a very severe infestation and if all other means no longer help, systemic agents may be used under certain circumstances. These are absorbed by the roots and distributed throughout the plant by the plant sap.

Category:

Garden plants