There was an article in the newspaper recently about using milk as a fertilizer. Extolling the virtues of milk, the articles also listed its anti-viral and anti-fungal ability. But, let's be realistic and check whether milk is any good or is it just a new fad. Listed below are a few pros and cons of using milk for orchids.

Pros
> Milk contains numerous minerals and vitamins. Many of which are required by plants including orchids, for proper growth. For example, milk has high content of calcium which is an essential mineral required by orchids for growth and development. Some users on internet assure that milk revives the dried out grass even if the temperatures are freezing.
> Milk does possess anti-bacterial, anti-fungal and anti-viral properties. That is why paediatricians all over recommend breast-feeding. In plants, it has been reported to be an effective remedy against aphids and powdery mildew. I have come across reports which indicate that milk application can also control Tobacco Mosaic Virus (or TMV).

Cons
> Milk contains many complex compounds such as proteins, fats and carbohydrates, which cannot absorbed by the orchids directly. If pure raw milk is fed to the orchids, then it can cause more harm than good. The thick consistency of milk can block the pores in medium and the fats deposited on the medium will attract all kinds of pests.
> Milk can get spoiled, and when it does it smells horrible. Too much milk poured on your orchid can result in smelly plants. Raw milk if used, is even more prone to spoiling. Then instead of aiding growth, the orchid may possibly have to face a new set of harmful microbes.
> Dried skimmed milk can cause black rot and soft rot in some other plants. So use this with caution for orchids.
> Feeding milk to plants, when there is so much of hunger/malnourishment around seems very unethical.

How to use: After reading both pros and cons, if you still want to fertilize your orchids with milk then do it properly.
> Use highly diluted milk for orchids. Make a solution of two thirds water mixed with one third milk. It can be used as foliar spray or can be poured onto the growth medium.
> Do not fertilize frequently with milk. You can do it once in six months.

Note
The milk mentioned here is boiled cow's milk. Other types of milks which can be used are soyabean milk, coconut milk. These are of plant origin and their method of use will be different from that of animal origin milks.

Recommended reading
1. Milk works as fertilizer
2. Lian Wu Hsiung's Wax Apple Farm