How to fertilize potted Phalaenopsis orchids? Latest techniques and methods tutorial
Phalaenopsis mainly relies on foliar feeding to promote plant growth, so during its growing season, spray once a week with a 0.1%-0.3% complete nitrogen-phosphorus-potassium fertilizer or potassium dihydrogen phosphate, as well as pesticides such as lime sulfur mixture, carbendazim, and thiophanate-methyl, to prevent and treat diseases. Phalaenopsis greenhouse cultivation can use soilless substrate culture or soil ground planting. Soilless substrates can be moss, peat, bark, etc. Several companies in Yunnan use moss as a potting substrate, applying nutrient solution as both water and fertilizer, with good results.
Phalaenopsis fertilization is basically carried out together with watering. Generally, macronutrients and micronutrients are dissolved in water in proportion, the pH is adjusted to slightly acidic, and then the whole plant is sprayed, 1-2 times a week, at a concentration of 0.1%-0.2%. It is best to use fertilizers that the plant can absorb directly.
When growing Phalaenopsis at home, you must master the correct fertilizing method to achieve strong roots, plump leaves, and brilliant flowers while avoiding fertilizer damage.
1. It is better for fertilizer to be dilute than concentrated. The fertilizing principle for Phalaenopsis is light fertilizer applied frequently, small amounts many times. Concentrated fertilizer easily causes root rot, especially when applying water-soluble quick-acting fertilizers. The dilution concentration must follow the multiple specified in the instructions; never increase the concentration on your own. Beginners are safer diluting it more than twice as much.
2. During the growing season, fertilize once a week or once every 10 days. The fertilization concentration should gradually increase from small seedlings to large plants. In addition, root fertilizer (referring to fertilizer applied to the substrate at the root zone) and leaf fertilizer (referring to foliar feeding applied to the leaf surface) are best applied alternately.
3. The types and methods of fertilization differ at different growth stages. When new shoots have just formed, the demand for nitrogen fertilizer is relatively high, but potassium fertilizer also needs to be included. When flower buds form, phosphorus fertilizer should be increased to promote flower bud development.
4. Fertilization during the bud stage or flowering stage should be appropriate. Fertilizing should not be excessive or too frequent, especially not too much nitrogen fertilizer, otherwise it will cause excessive plant nutrients, stimulate vegetative growth, thereby shortening or offsetting the ongoing reproductive growth, causing early bud drop (bud blast) or withered flower buds.
5. Fertilizer is most easily absorbed by Phalaenopsis when the temperature is 22-28°C. Therefore, in spring and autumn it is best to fertilize in the morning, in summer it is best to fertilize in the evening, and in winter when temperatures are low or when a cold wave hits, fertilize less or avoid fertilizing. In cold or extreme heat, when temperatures are too low or too high, Phalaenopsis will enter dormancy or semi-dormancy, and fertilizing is also inadvisable at this time. Because when the plant is dormant or semi-dormant, its internal activity is greatly reduced, and with the stomata closed, water evaporation is almost zero, so it has no ability to absorb fertilizer. Fertilizing at this time is undoubtedly wasteful, and the fertilizer will also accumulate in the growing medium, causing the substrate to acidify prematurely. If not handled carefully, it can also hinder root crown growth or even cause root rot.
6. Fertilization should be even and the method should be appropriate. When applying water-soluble quick-acting fertilizer, drench the entire pot until fertilizer water flows out from the bottom of the pot. The leaves should also be moistened, because Phalaenopsis leaves, like the roots, can also absorb fertilizer. When applying solid fertilizer, spread it evenly so the roots can absorb it uniformly; never pile it up at the root zone, otherwise the fertilizer at that spot will be too concentrated and burn the aerial roots.
7. Orchids that have just been planted or just repotted should not be fertilized for the time being. Because during planting or repotting, the plant's root system is damaged or broken, and fertilizing at this time can easily cause the root wounds of Phalaenopsis to become infected with pathogens, resulting in root rot.
8. When the plant suffers from pests or diseases or when the plant grows poorly, it is also best to temporarily stop fertilizing. Because at this time the absorption capacity of Phalaenopsis is weak, fertilizing is undoubtedly wasteful and may even worsen the condition, making weak plants weaker.
9. When root rot occurs or the growing substrate has rotted, fertilization should be suspended. First take the orchid plant out, remove the rotted substrate, then cut off the rotten roots and replace with new growing substrate to replant. Resume fertilizing only after normal growth has recovered and new roots have grown.
Fertilization precautions:
The principle of fertilization should be to fertilize less and apply dilute fertilizer. Because it grows relatively quickly and its growth period is also relatively long.
Precautions by fertilization month: Phalaenopsis grown for one year or many years will be repotted every year in late spring and early summer (May). Phalaenopsis that has just been repotted is in a recovery period and should not be fertilized. After a month of recovery, the orchid plant begins normal growth. That is, from June to September, the orchid plant enters the growing season, and it needs to be fertilized once a week.
Fertilizers suitable for Phalaenopsis: foliar fertilizer, potassium dihydrogen phosphate, fermented farmyard manure diluted with water, special orchid fertilizer, etc. During the growing season, foliar fertilizer and potassium dihydrogen phosphate can be used alternately to fertilize Phalaenopsis. If these two fertilizers are not available, you can choose fermented farmyard manure diluted with water to water with fertilizer solution. If you have special orchid fertilizer at home, apply the special orchid fertilizer directly.
Spring and summer fertilization precautions: Summer temperatures are relatively high, so fertilizing the orchid plant should be stopped. In autumn, the growth rate of Phalaenopsis begins to slow down, and the frequency of fertilization should also be reduced. If the orchid plant is fertilized frequently at this time, it will affect flower bud formation, making it difficult to bloom.