Laurel tree has brown leaves - diseases + pests on laurel


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Laurel Tree - Laurus nobilis

Since the real laurel is very sensitive to high salt concentrations in the soil, it should preferably be fertilized with organic long-term fertilizer. Blue seed, high amounts of liquid fertilizer and the like lead to the death of the leaves and shoots in no time. If that is the case, the shrub can still be saved if you act quickly.
  • Remove the plant from the pot and remove as much substrate as possible
  • first by hand
  • with the spray of the garden hose, wash out remaining soil
  • Let it dry for a few hours
  • convert into fresh, high-quality substrate
  • easy to water
  • first set up a bit more shady
If the bale is already very heavily rooted and fails to completely remove the soil, it may help to place the root ball in a bucket or tub with fresh (room warm) water. The salts are usually very soluble in water and can be flushed out. Leave the plant in the water for about five minutes and occasionally lift the bale to ensure better mixing.
Then let the roots drain well. This procedure is repeated about three times to dissolve solid residues of the excess fertilizer. Then the laurel can be potted into fresh substrate.

Wrong cut

Often, a few days after a cut, brown leaf margins appear. The spice laurel responds to a violation of the leaves with drying at the interfaces. In principle, this does not pose a threat to the health of the plant, it just does not look very pretty. To correct the damage, you must not cut off these brown spots, because that only has the consequence that the underlying tissue dies again.
  • new cutting measures necessary
  • do not cut through the leaves
  • always cut just above a leaf approach
  • Shorten all affected shoots in this way

pests

In addition to the above-mentioned weather-related damage and care errors, the laurel tree is also occasionally the victim of pests, which occur especially in warm winter quarters. These include:

Scale insects

Scale lice are a parasite that feed on plant juices. To do this, they absorb the cells mainly on soft and young tissue. That alone weakens the real laurel already strong. On top of that, the animals also give off toxins that lead to discoloration and death of the tissue. Scale insects have an oval or round, light to dark brown sign. They are found on fresh, unpolluted stems and leaves.

Laurel Tree - Laurus nobilis


As a rule, these are female animals that cling to the plant via a so-called suction spike. Under their shield, which consists of paint and wax, they raise their offspring (up to 2000 boys). The larvae can not be seen with the naked eye, but they spread throughout the plant, sucking their juices and excrete sugary feces, which then leads to Russtaubildung.
symptoms:
  • stunted growth
  • necrosis
  • brown leaves
  • Formation of honeydew and dew
fightIf the laurel is attacked by scale insects, it must be urgently isolated from other plants, otherwise there is a risk that the animals continue to spread. Control is easier with plants that have already moved into their summer quarters outdoors than with plants in winter quarters.
  • cut out diseased shoots
  • Dab louse with a cotton bud soaked in alcohol
  • Release stuck animals with a fine (tooth) brush
  • Wash the entire plant with warm greasy soap solution (1 l of water plus 1 tablespoon of soft soap)
  • then spray with a mixture of paraffin and rapeseed oil
  • alternatively use neem oil
  • Repeat procedure after 10 to 14 days (next generation)
  • natural enemies: ladybugs and parasitic wasps
  • pour with stinging nettle
  • inject fresh shoots with a mixture of paraffin and rapeseed oil
  • Sprinkle container plant with water and place in transparent plastic bag
  • dwarfed for two weeks
Tip: If you use pesticides to control pests, you will not be able to harvest leaves for consumption in the next few weeks and months.
prevention
Since scale insects generally only attack weakened plants and also prefer certain living conditions, a few basic measures for prevention are recommended.
  • cool winter quarters (around 5 degrees)
  • as much light as possible
  • do not use nitrogenous fertilizers
  • Occasionally spray at low humidity

Lubricants (WolllÀuse)

Woll lice are closely related to the scale insects.Instead of the typical shields, these parasites protect themselves with wax, which they produce in special glands. Most of the animals themselves are difficult to recognize on the laurel tree. Characteristic of an infestation with mealybugs is a fine, whitish web. These wax threads cover the animals and protect them from dehydration and the sun. Unfortunately against most sprays. Some species lay eggs, others give birth to their offspring. Woll lice excrete large amounts of honeydew and are therefore protected in the field by ants against natural enemies. In potted plants, the citrus louse often occurs. The lice suck on the leaves and excrete toxins at the same time.
symptoms
  • usually the infestation begins in the leaf axils
  • on shoots and leaves a white, cotton-like web is recognizable
  • Leaves curl up and turn brown
  • sticky honey drops form
  • additional infestation with Russtau (black coverings)
fight
The first step in combating pests is always to prevent further spread. Separate the diseased laurel from other plants.
  • Cut out affected and diseased parts of plants generously
  • Wash the whole plant with a soft soap solution (1 tablespoon of soft soap / liter of water)
  • spray with paraffin oil
  • then put in a transparent bag for 2 weeks (shady)
  • be cooler in the winter quarters
  • alternatively: in good weather place potted plants into the open air
  • natural enemies: ladybirds, lacewings larvae, parasitic wasps, hoverflies
prevention

Laurel Tree - Laurus nobilis

Already with an optimal location (summer and winter) and the right care you can prevent a pest infestation. Strong, healthy laurel trees are rarely attacked by pests.
  • Sow nasturtium on the surface of the earth
  • Spraying horsetail tea to fortify the plant
  • Avoid nitrogenous fertilizer
  • spray young shoots with paraffin oil / white oil in winter and spring
In addition, you should protect the spice laurel year-round ants, as these lice literally cultivate and protect against natural enemies.
Conclusion
On the whole, the spicy laurel is a pretty sturdy plant that rarely gets sick. The high concentration of essential oils in the leaves alone protects the wood from most common pests. Usually it is care mistakes that weaken the real laurel, so it comes to die. In most cases, the plant can be saved by rapid intervention and targeted countermeasures.

Video Board: PLANT LEAF DRYING and BROWN at TIPS AND EDGES: Top 5 Reasons - Diagnosis Cure and Hacks (Tips).

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