Fertilizer Frustration

[DebbieW]

As a newbie I'm a little frustrated and confused with what fertilizer to use on my different orchids. Are there different fertilizers for different types of orchids or can one general fertilizer be used? I have oncidium, vanda, paph, dendrobium, cattyleya, and phalenopsis. Thanks!

[Merlyn]

I use the same on all but I do vary the strength. The general rule is 1/4 or 1/2 the strength listed on the container. I use 1/2tsp per gal for about half of my 168 chids including Phals, Bulbophyllums, Dens, Cattleyas but change for the 72 Catasetums because they are voracious feeders doing massive growth in one season and I use full strength 1tsp/gal for them. I've found that urea free is the best kind, different brands make it. Hope that helps !

[tucker85]

If you ask 10 orchid growers what fertilizer to use you'll get 10 different answers. Having said that, I use the same fertilizer on all my orchids. Like Chryss said, I use about 1/4 strength once a week during the summer and less often during the winter. I feel that any fertilizer is better than none. It can't hurt to buy one that's designed for orchids if you can find it.

[Discus]

You can use one general fertiliser for all your orchids, but bear in mind some like more or less of it. Urea-free (nitrate/ammonium based) is better.

It's a good idea to match your fertiliser to the water you're using (i.e. don't use "tap/well" water fertiliser with RO/Distilled/Rain water and vice versa.


Here's a reference table of the ballpark figures for the concentration of fertiliser that orchids can take based on EC (NB there is some variation within genera, plus not all EC meters and fertilisers are equal):

400μS/cm: Cattleya, Paphiopedilum
600μS/cm: Odontoglossum, Coelogyne, Lycaste, Oncidium, Masdevallia, Miltonia
800μS/cm: Phalaenopsis, Cymbidium

[Merlyn]

Discus, you left out Catasetum.