Fresh, crunchy lettuce from the garden enriches every menu. Too bad it's also very popular with aphids. Find out below how you can fight lice.

In a nutshell

  • Over-fertilization, the wrong location, warm and humid weather all encourage infestation
  • deformed leaves, sticky leaf coating, ants indicate the presence of aphids
  • don't fight with chemicals
  • various home remedies work well

Various causes possible

There is not only one cause for the infestation of lettuce with aphids (Aphidoidea). Various factors play a role in this. It is important that the earlier an infestation is detected, the sooner something can be done against these pests. Causes can be:

Bjankuloski06en, Oak Leaf Lettuce, edited by Plantopedia, CC BY-SA 3.0
  • Overfertilization of the soil with nitrogen
  • wrong location
  • only cultivation of monocultures
  • insufficient plant spacing
  • low air circulation between the plants
  • humid and warm weather
  • low vitality of plants

Recognize the lice

The lice, which are only two to four millimeters in size, can be seen with the naked eye if you look closely. They can come in different colors from black to reddish brown to green. The pests that spread in the salad are a little more difficult to see. They usually hide deep in the leaves. Sure signs of the presence of lice are:

  • deformed and curled leaves
  • sticky leaf coating (honeydew)
  • bad growth
  • a flock of ants
  • partially present sooty mold

If an infestation is detected, immediate action is required to prevent further spread and multiplication of the lice.

Tip: Infested leaf lettuce must be washed thoroughly before preparation in the kitchen. To do this, some salt and a few dashes of vinegar should be added to the cold water. The leaves should remain in it for two minutes.

In order to get rid of the aphids, you should not immediately resort to the chemical club. This can not only be harmful to human health, but also causes lasting damage to the environment with its useful helpers such as insects and other microorganisms. With a light infestation, wiping the leaves by hand or a gentle jet of water from the garden hose is sometimes sufficient. In addition, the use of various home remedies to combat the lice in the salad is possible. Below is a small list.

vegetable brew

nettle brew

This brew not only drives away lice, but also strengthens the plants' defenses at the same time. The production is simple:

  • Finely chop 100 g fresh stinging nettles
  • don't use flowers
  • then top up with 1 liter of cold water
  • leave for at least 12 to 24 hours
  • choose a sunny, warm place for this
  • then boil the mixture for 20 minutes
  • cool, strain and pour into a squeeze bottle
  • Application every two to three days

If possible, rainwater should be used for production.

Notice: Adding some wood ash can reduce the smell of the brew.

horsetail brew

The broth strengthens the cell structure and protects against aphids, mildew, gray mold and scab.

  • 1 kg fresh or 200 g dried herb
  • Add 10 liters of water
  • leave in a warm place for 24 hours
  • then cook for 30 minutes
  • let cool and strain
  • Dilute 2 liters of brew with 10 liters of water
  • Spray plants every 2 to 3 days
  • also used as irrigation water

Notice: The brew is only effective against aphids in the early stages, but can be used to prevent them.

Garlic and onion broth

  • Chop 40 g garlic cloves or onions
  • Pour 1 liter of boiling water over it
  • Leave for 3 hours
  • strain, decant into squeeze bottle
  • Application several times a day

Notice: The broth also helps against fungal diseases. Alternatively, garlic can also be planted between lettuce. The smell scares the animals away.

Oregano Tea

  • 100g fresh oregano or 10g dried per liter of water
  • Pour a liter of boiling water over the cabbage
  • Leave for 30 minutes
  • strain
  • Use only diluted
  • 3:1 ratio with water
  • Spray every 1 to 2 days several times a day
oregano

Tip: Alternatively, wormwood or black tea (two tea bags) can also be used.

potato water

Aphids don't like the solanine released when potatoes are cooked. Simply allow the cooking water to cool and then spray the plants undiluted with it every one or two days.

milk-water mixture

  • 1 liter fresh milk, no UHT milk
  • 1 liter of cold water
  • mix everything
  • Spray plants once or twice a day

rapeseed oil

  • 100ml oil
  • 5 liters of water
  • 1 to 2 squirts of dish soap
  • mix everything well
  • Spray plants daily
  • Results are already visible after the third application

coffee grounds

Coffee grounds make an excellent fertilizer and are a good home remedy for aphid control.

  • 4 tablespoons of coffee grounds
  • 1 liter of water
  • 1 tablespoon of milk
  • Brew coffee grounds again
  • cooling down
  • add milk
  • spray plants for a few days

Tip: Alternatively, leftover cold filter coffee can be used.

Natural predators

A spread of the pests can be prevented in a natural way by using predators. These can find shelter in an insect hotel and can be used in the beds in a targeted manner. Larvae of these animals can be obtained over the Internet. Natural predators include:

  • ladybug
  • gall midges
  • hoverflies and lacewings
  • parasitic wasps
  • catchy tunes

Notice: A ladybug can eat up to 150 aphids per day. The larvae have a particularly large appetite.

mixed culture

Planting different aromatic plants between the individual lettuce leaves has also proven itself. The odor that emanates drives away the lice. These include:

spice tagetes
  • tagetes
  • savory and sage
  • garlic and onions
  • anise and coriander
  • lavender and mint
  • Parsely

frequently asked Questions

Can lettuce be infested with lice?

The animals are completely harmless to humans, even if they may be eaten. They do not bite or sting, nor are they poisonous. However, they can harm the affected plants. They suck out the plant sap with their proboscis. The development of the plants is disturbed. In the worst case, they die. There may be a large crop failure. They can also transmit viruses and fungal diseases can develop.

Why can aphids spread so quickly?

Initially, the lice are sexless. However, they become sexually mature within a few weeks. Such an animal can then produce up to five offspring per day. If left unchecked, the aphids can quickly form large colonies.

How can a lice infestation be prevented on lettuce?

Prevention is not only possible with lettuce, but with all plants. Enriching the soil with nitrogen can be very helpful, but do not over-fertilize. This can otherwise become a cause of an infestation. Furthermore, a suitable location with sufficient planting distances is important. Regular watering is also necessary, but avoid waterlogging. Choosing aphid-resistant varieties can also help, as can setting up an insect hotel.

Category:

Garden pests