The yellow leaves of orchids are related to the application of fertilizer

Fat yellow

Excessive fertilization, especially too much nitrogen fertilizer and lack of phosphorus and potassium fertilizer, is easy to cause leaves to turn yellow, showing that the new leaves are thick, the leaves are mostly uneven, the old leaves gradually turn yellow and fall off, when the leaf tip is serious, even the whole leaf is scorched yellow. In this case, you should apply fertilizer immediately, increase the amount of water, let the fertilizer flow out of the drain hole, or pour the basin immediately, remove part of the old soil, wash the soil block with water, replace part of the new culture soil, and then plant the plant back into the basin.

Hungry yellow

The lack of fertilization, especially the lack of nitrogen nutrition in the soil for a long time, leads to thin and yellow leaves and branches, so it is necessary to pour the plant out in time, replace it with a larger pot, put it into a new loose and fertile culture soil, and replant it. After pouring water, put the seedlings in a semi-shady place to slow down the seedlings. After its growth resumes, thin liquid fertilizer or compound chemical fertilizer is applied.

Alkali yellow

When planting flowers that like acid soil in the north, such as camellia, orchids, Michelia, Mizi, sweet-scented osmanthus, because the soil in most areas of the north contains more salt and alkali, the above flowers and trees will gradually lose green and turn yellow due to the lack of soluble iron elements that can be absorbed by flowers after a period of time. At this time, 0.2% ferrous sulfate solution can be poured at intervals, while 0.1% potassium dihydrogen phosphate solution can be applied alternately to cure the "alkali yellow". At the same time, potassium dihydrogen phosphate also contains phosphorus and potassium elements, which is conducive to flower bud differentiation and improve flower quality.

Acid yellow

Southern China is red loam, the soil is acidic or slightly acidic, magnesium in the soil is easy to lose, leaves often show old leaves, leaf veins are first green and yellowing, can apply calcium magnesium phosphate fertilizer or spray 0.1% to 0.3% magnesium sulfate solution. For the improvement of acid soil, attention should be paid to the application of rotten organic fertilizer, lime and a small amount of lime, which can not only neutralize the acidity of soil, but also promote the decomposition of organic fertilizer.