rose food for orchids?

[florissantti]

I went and got some fertilizer today and had to choose between lots of different types (unfortunately, none was advertised as for orchids in particular). I wanted to get something somewhat balanced. The stuff for just "regular plants" was something like 30-10-10. I ended up with Miracle-Gro Rose food. It's 18-24-16 (nitrogen, phosphate, potash respectively [not sure if that is the order it's typically listed in, but that's how it is in the ingredients]). I'm not sure if this is relevant, but it also contains 0.05% copper, 0.10% iron, 0.05% manganese, and 0.05% zinc. I just want to make sure that this was the optimal fertilizer to get.

The other choices available were: general plants, tomatoes, flowering plants, azalias. I also want to use this for my other houseplants. Right now I have a phal in sphagnum and a vanda in coconut husks (which i realize will need a higher nitrogen fertilizer eventually).

Thanks for any responses.

[jerrymeola]

A very good question. I was not aware there were so few choices in other areas.

you are right about the numbers. Nitrogen the first number is used to grow leaves, phosphate the second number for flowers and potash for roots.

I generally recommend a balance 20-20-20 mixture but the 18-24-16 is close enough. Peter's and Miracle Grow both make an all purpose fertilizer in 20-20-20 that is usually carried in all the big stores.

MOST IMPORTANT is that the level of fertilzer is too high for orchids. The recommendation for dilution is probably about a tablespoon per gallon for roses. (I personally do not like granular fertilizers- it is too hard to control the levels. I always use water diluted mixes)

Orchids get fertilized 'weakly weekly a weak solution of about a teaspoon per gallon not a tablespoon and used once a week.

Some packages are labled Orchid Fertilizer at 30-10-10. This is often recommended for orchids packed in bark especially as the bark gets older. As bark decomposes it uses nitrogen to break down. As a result 30-10-10 on an activily growing plant may really be closer to 10-10-10 for the plant and 20 nitrogen for the bark. It is not recommended for plants in hydro stones, sphagum moss or other none bark mixes. I use 20-20-20 for both my bark and hydro pots and they do excellant.

Tomato fertilizer would also have been a good choice. I notice that your fertilizer does not have any magnesium. Orchids need magnesium. It might be wise if once a month you added a teaspoon of epsom salts (pure magnesium) to a gallon of your fertilizer water. Orchids also need calcium, but that is present in tap water.

when i remember i use miracle grow at 1/4 strength. i have experimented with african violet food , as well as a blossom booster , green light super bloom 12-55-6 with chelated iron at the same strength. not all at the same time, lol. the best result, flower count, etc was with the green light applied as the new growth reaches maturity. but it could have been other factors, maybe the alignment of the planets, etc. who knows for sure?