What are the control methods for iron deficiency in potted flowers?

In northern regions, potted southern evergreen flowers such as camellia, sago palm, kumquat, and azalea often suffer from iron deficiency chlorosis, causing poor growth of the potted flowers.

I. Main causes of iron deficiency in potted flowers

1. Soil causes. Southern soil is generally acidic, with more soluble iron in the soil, which can meet the needs of flowers and plants; however, in northern regions the soil is alkaline or has a high calcium content, and the iron in the soil is generally in an insoluble state, so the root system of flowers and plants cannot directly absorb iron, resulting in iron deficiency symptoms.

2. Water causes. After long periods of rain, water accumulates in the pot, oxygen in the potting soil is insufficient, and the root system's nutrient uptake is impaired, which also often causes iron deficiency symptoms.

II. Main symptoms of iron deficiency in potted flowers

Iron deficiency in potted flowers first shows on young leaves, while symptoms on old leaves are generally not obvious. The veins of young leaves remain green while the leaf tissue turns yellow; in severe cases the entire leaf turns yellow. After iron deficiency, photosynthesis is affected, the flowers grow poorly, and their ornamental value declines.

III. Methods

1. When potting southern flowers and trees such as camellia, sago palm, and kumquat in northern regions, it is advisable to use acidic mountain soil and other soil materials, mixed with other soil materials to make an acidic nutrient soil for potting, which can keep the nutrient soil acidic for a relatively long time; in this way, the flowers are less prone to iron deficiency.

2. Mix ferrous sulfate, soybean cake, pig manure, and water in a ratio of 1:2:6:100, place in a vat to ferment, and expose to sunlight. When all has decomposed into a black liquid, it can be used to water potted flowers. Take the upper dilute fertilizer liquid, dilute it with water, and water the flowers; then fill the fermentation vat with water again to ferment once more, and thereafter take the upper fertilizer liquid and add water for use. Fertilize every year from after the flowers begin growing in spring until summer, about 4 times a month.

3. During the growing period, when the leaves of potted flowers turn yellow and early symptoms of iron deficiency appear, a 3% ferrous sulfate solution can be applied to the pot, with good results.

4. When iron deficiency symptoms occur in potted flowers, ferrous sulfate and urea can also be used in a 1:2 ratio to prepare a 0.2% ferrous sulfate solution and sprayed on the leaf surface, which can also promptly treat iron deficiency.

5. When potted flowers are growing rapidly, iron deficiency and yellow leaves often occur due to excessive rain; in rainy seasons such as the plum rain season, rain-sheltering measures should be taken, temporarily placing the potted flowers indoors or under a shed. In addition, in rainy seasons, when there is a lot of accumulated water in outdoor potted plants, promptly lay the pots on their sides to drain.