Yellow leaves / brown spots on orchids

Orchids are among the most popular indoor plants in Germany and enchant with their intense flowering and the lush green of the leaves. If the substrate is right, orchid plants require little care and have fresh leaves every year. But every now and then it can happen that a mistake happens during the care that turns the leaves yellowish and causes brown spots on the orchid. Different causes can be the case, which should be treated immediately.

causes

The causes of the symptoms

The right substrate, fertilization, watering and light are important when caring for orchids. Due to its robust nature, it takes a long time for the orchid to develop yellow leaves or brown spots, which indicates a severe imbalance in the plant's nutrient balance. There are a variety of causes, all of which need to be treated differently.

• Waterlogging
• Excess lime
• dryness
• Excess sun
• Overfertilization
• Pests

Please note, if your orchid has yellow leaves, you should never cut off the leaf or the tips. The risk of infection via the cut surface is too high and affects the orchid even more.

Waterlogging

Eliminate waterlogging

If orchids are doused or drown for any other reason, the leaves will turn yellow. This is because the roots have to dry out a little every now and then so that the roots don't rot. If the roots rot, the absorption of moisture and nutrients is inhibited and the plant can only grow to a limited extent. As a result, the leaves turn yellow. You can recognize waterlogging by a substrate that is too wet and often the orchid can only be saved with fresh substrate. Depending on the type of orchid, a typical orchid substrate or ordinary soil is used. Renew the substrate as described below.

• Detach the plant from the substrate
• Rinse off roots
• Cut off rotten roots with a sharp, disinfected knife or scissors
• Fill dry pot with substrate
• Allow the roots to dry a little before planting
• then put in the substrate
• Fill in the rest of the substrate and carefully fix it

When you have repotted the orchid, you shouldn't water the orchid, but rather spray it regularly for the first two to three weeks. Likewise, no fertilizer may be used for the next two weeks. If you have a terrestrial orchid, drainage can also be integrated into the pot.

Tip: Dip the root ball of the earth in soft, lime-free water about every two weeks. So the roots can soak themselves up and do not have to be watered for a long time, which prevents waterlogging extremely well.

dryness

Do not let it dry out

Even if too much water isn't good for the orchid, it shouldn't dry out either. The moth orchid Phalaenopsis, for example, which is so popular in Germany, is one of the classic tropical orchids and requires very little water, but should never forget to water will. If an orchid is too dry, three symptoms appear in the following order.

• Plant material becomes soft, slightly rubbery
• Leaves turn yellow
• Leaves turn brown in places

Soft plant material is not always noticeable, as not everyone examines their orchid with their hands every day. Therefore, for many people, the dryness only becomes noticeable once the leaves have changed color. If the leaves turn brown, the plant is dying of thirst and needs moisture immediately. The best solution for this is to carefully lift the plant out of the substrate and then immerse it in soft water. Let the orchid sit in the immersion bath until all air bubbles have disappeared and the roots, which are white at this point, have turned green again. Repeat this procedure every two weeks.

Note: If the humidity in the room is too low, the plant can dry out as well. For this purpose, lime-free, lukewarm water is administered daily via a spray bottle.

lime

Harmful excess lime

Orchids are not good with lime because of their natural location and this means that the roots can no longer absorb nutrients from the fertilizer. This is followed by the yellowing of the leaves with subsequent brown spots. An excess is only possible if you use the wrong fertilizer or tap water with a high content of lime, which is typical for Germany. Therefore, from this point on, you should only use soft water. This can be obtained as follows.

• collect rainwater
• use a water filter
• filter water with peat
• Boil water and let it cool down

Now you can fertilize again without any problems and the lime is slowly washed out of the substrate and dissolved. The orchid can then absorb the nutrients from the fertilizer again and recovers over the next few weeks.

Fertilize

Too much fertilized - discoloration ensues

As is well known, orchids need a special fertilizer that is tailored to the needs of the plant. Conventional fertilizers for flowers and other plants contain too high concentrations of salt, organic fertilizer is only recommended for terrestrial orchids due to the substrate. Many newcomers to the orchid field make the mistake of using incorrect fertilizers or excessive amounts of concentrate. Here we recommend: less is more! Orchids require little preparation and can even withstand long fertilization-free periods. If yellow leaves with brown spots appear, there is a suspicion of over-fertilization. Then you should proceed as described below.

• remove the orchid from the substrate
• look at the roots and remove any rubbery strands that are black or brownish in color;
• be sure to leave the other roots on
• rinse the roots thoroughly
• prepare new substrate
• put the plant in the fresh substrate
• Do not fertilize until the next season!

Through this measure, the orchid plant can again absorb enough fertilizer in the coming season, but is still fed for the entire season due to the overfertilization. Also pay attention to the following typical mistakes when fertilizing.

• Never put fertilizer directly on the substrate, but rather in the irrigation water
• always use less fertilizer than is prescribed, unless it is high-quality, special natural fertilizers such as the guano preparations from Neudorff
• some algae extract in the irrigation water is used to relax the stressed roots

sunburn

The sunburn in detail

Orchids are tropical plants, but that doesn't mean that they can withstand direct sunlight for hours. Owners often place their specimens in the blazing sun and wonder why the leaves turn yellow and sickly brown. Immediately relocate the plant if sunburn is suspected. You can also recognize this by the extremely dry leaves in this discoloration. A bright location with little direct sunlight over midday is ideal for the orchid. Then spray daily with lukewarm water or install a humidifier near the flower.

Pests

Pests drain your life force

Orchids are robust, but even against pests they cannot do anything without proper care. The main pests of the plant, which are often responsible for yellow and brown leaves, include mealybugs and mealybugs. These are located on the shoots and leaves of the Orchidaceae and feed on the sap that the plant needs to survive. During the infestation, the pests continue to multiply rapidly and exacerbate the problem. They can be recognized by the white fluff that they weave around them for protection. Use the following means to remove the pests.

• wet a cloth with alcohol and wipe the plant
• soak a cotton swab in alcohol and blot the mites off
• pack the orchid in a plastic bag for two to three days to cut off the oxygen supply to the mites

If you are lucky and the mites are no longer visible, you can also rinse the orchids daily with water to protect them from additional infestation.