When to fertilise?

[Orchidpeeps]

Hello

How long after repotting a phal do I start to fertilise an orchid?

Also, anyone have thoughts on Seasol Seaweed Concentrate as a supplement (not fertiliser) for the orchids?

[jcec1]

Given you are in the southern hemisphere I would fertilize it as per your normal routine. Unlike potting composts that generally have added fertilizer, bark has no fertilizer reserves so there is no need to wait until they are used up.

I don't use your particular brand of seaweed as a supplement, but use something similar. As I use it on all my plants I can't say for definite that it 'works' - I don't have a control group to compare it too. But, it does not have an adverse effect, other than an occasional distorted bloom so I will continue using it.

[Luizacft]

I fertilize when the plant shows new growth or new roots. Right after repotting, I use a fertilizer which is supposed to help the plant to produce roots. If the plant is doing nothing (is dormant) - I don't care to fertilize regularly. I use the 'plant will tell you' method for fertilization :-)


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Do. Or do not. There is no try.

[Subrosa]

Seaweed products are intended mostly to stimulate root growth, so after repotting is an excellent time to use them.

[bil]

I use a very weak fertiliser at every watering except for the winter rest plants.

I also do a light kelpmax dose every month.

[Orchid Whisperer]

Specifically for Phalaenopsis, assuming a healthy plant: I repot differently from some other growers. I repot in bark or other growing medium, dry. I wait a day or two after repotting before watering (allowing roots to heal that might have been damaged during repotting).

After a week or two, I use fertilizer and seaweed (kelp) extract on a routine schedule, aiming for about once every month in winter, twice a month in summer. 11-35-15 applied at 1/4 the manufacturer's recommended concentration. Nothing magical regarding this formulation, I sometimes use other formulations, and I use both urea-containing and non-urea fertilizers. At present, I like low N fertilizers for mature flowering-size plants. Kelp extract applied monthly at manufacturer's recommended rate. BTW, kelp does contain plant macro- and micro-nutrients.

Don't forget Ca and Mg; I also supply these as gypsum and Epsom salts dissolved in water (also supplies S). These elements are helpful in preventing diseases and nutrient deficiency.

I view Phalaenopsis as never truly dormant. Even when leaves, flower spikes and roots are not apparently growing, they are absorbing nutrients for the next round of growth. You want the plant to be ready to grow.

[camille1585]

Originally Posted by bil

I use a very weak fertiliser at every watering except for the winter rest plants.

I also do a light kelpmax dose every month.

Bil, where did you get the Kelpmax from? I didn't know it could be found in Europe.

[bil]

Originally Posted by camille1585

Bil, where did you get the Kelpmax from? I didn't know it could be found in Europe.

No, it's only available in the US.

[camille1585]

Originally Posted by bil

No, it's only available in the US.

Oh well. I may be going there sometime this year, and could have some delivered to one of my friends, and then bring it back with me.

[Ray]

Originally Posted by camille1585

Oh well. I may be going there sometime this year, and could have some delivered to one of my friends, and then bring it back with me.

It has been done before!