Hoyas share the same general habitats as many epiphytic orchids so they will have no problem sharing the same fertilizer as your orchids. One of the things you will find if you talk to serious orchid growers is that they pay close attention to the fertilizers they use and the ppm of the water and the final fertilizer solution. You will often hear people say that this or that plant does not need fertilizer and in some cases this may be true or at least a specialized fertilizer for plants such as slow growing cacti however, Hoyas are in many cases large growing tropical vines and they need fertilizer if they are expected to perform well in a pot.

I fertilize my Hoyas all year round but during the spring growth period that we see with our plants a little extra Nitrogen would be helpful. Yellowing leaves can be helped by using 1 TBSP of Epsom salts per gallon of water.

So what Coelogyne are you growing, cool conditions make me think of Coelogyne cristata. Coelogyne is one of my favorite genera of orchids and I have eight different warm growing species. I have given up on the cool growers because I just can't offer them what they need to bloom.

Mike

Renee,

I recently switched to a 10-5-14 for growth (very close to yours)and all is well so far!

Mike, what are the numbers on the fertilizer you use?

Good question, Renee! I have to admit I'm lost when talk turns to fertilizers!

Mike thanks. I mix up the fertilizer solution to 100 ppm N, with that level, and that I don't use bark as a potting media for the orchids at all, I fertlize about twice a week when they are outside. That seems a lot for orchid growers, but they get thoroughly washed out a couple times a week due to rainstorms or me with the hose.

I'll increase my fertlilizing frequency of the Hoyas a little more than the once a month I have been giving them. As for MgSO4, I usually add some into the fert solution maybe twice a summer. I'll make sure to do that this week.

Yeah, cristata is a breathtaking Coelogyne. Unfortunately it is one that didn't survive the summer here. It seems like the other cool growers I grow will tolerate the summer, and make strides during the winter.

Right now I have two Intermedias (both in bloom), a multiflora, flaccida, gardneri, and one species that I lost the tag to,and can't remember the name of. It's in bud right now, for the first time, so once it blooms, I'll be able to figure out what it is.

I also have trinervis, but I don't keep him with the cool growers, its more intermediate to warm growing.

Here's a pic of one of the Intermedias from this month.

And my trinervis from last fall.

Kelly, yes our numbers are pretty close. I think I was just not fertlizing often enough at the strength I mix it up to.

On top of that, our water here is amazingly good. I actually called the water department and had a discussion with the lab person who runs the tests. So between rain doing half the watering, and the tap water being so good, I have to rely on the fertilizer for pretty much all the trace nutrients.

Your Coel. trinervis is gorgeous but Coelogyne multiflora, that is the species at the top of my Coelogyne wish list. I am hoping to have a broker import multiflora for me this spring from Asia.

Kelly I use mostly organic fertilizers but also DynaGRO GROW 7-9-5 although the Foilage Pro 9-3-6 is supposed to be a great product so I will try that one next. Michigan State University (MSU) fertilizer is a huge hit with professional and hobby orchid growers and their formula also has numbers that are similar to Foilage Pro in that the middle number is the lowest. Those bloom booster fertilizers you see offered have been proven to be expensive and not very useful so stay away from those.
I have to admit that I am very fond of using fish and seaweed based fertilizers and that is what I am currently using.

Mike

Kelly, I am a big fan of Dyna-gro Foliage Pro 9-3-6 and have been using it for quite some time and I really like it. I agree with Mike about avoiding using the "bloom boosters"...I think its an overkill and might be harmful if used often. So I quit using them a while back.

I also add a tsp. of fish fertilizer and kelp to my Foliage pro...I fertilize my plants year round as well...a lot less amount in winter and a little more during the warm growing season.

Puglvr1, what's the benefit(s) of adding fish fertilizer and kelp? And do you do this once in a while or everytime you water/fertilize? Thanks!

I've been using FP and I'm very pleased with it also. :)

FP 9-3-6 is what I use, and I really like it as well. I've seen the suggestion to occasionally add large amounts of epsom salt, but I would definitely avoid this. First of all, 1 Tbs per gallon (a frequently suggested dose) is way too much. Not only would it provide over 300 ppm Mg, but it would raise the TDS level over 3000 ppm. Secondly, Ca and Mg should be provided in a specific ratio. Adding too much of one relative to the other can cause an antagonistic deficiency. If you really believe you have a Mg deficiency, try spraying the leaves with an epsom salt solution of 1/4 tsp per quart. If the color improves, then try adding 1/8 tsp epsom salt per gallon when watering.

Of course FP contains both Ca and Mg, so there should be no worries of deficiencies when using such a fertilizer.

I just tested my tap water with a TDS meter and it is not bad at 144 ppm. After adding 1 TBSP Epsom salts to a gallon of water the reading was 651 ppm which I agree is quite high, not sure how your reading made it to 3000 ppm unless you have rather hard water and you were referring to having added the Epsom salts to a fertilizer solution? The 1 TBSP Epsom salts per gallon of water could easily be reduced like you mentioned. I used to use 1 TBSP per gallon for my potted Brugmansia when they were producing new growth or a large flush of blooms and their leaves started to yellow, worked like a charm to green them back up. I have never noticed any ill effects from a stronger solution although the possibility of root damage is always there when fertilizer salts build up in the potting media and are not flushed out with plain water; still why use more than you need for any given purpose.

I usually aim for a fertilizer solution that it not much over 300 ppm and this allows me to fertilize more often without the problems associated with large doses of fertilizer. I can get away with this where I live but other areas have much harder water and mixing fertilizer as per product instructions can be disastrous. I used to live in a community where the water was so hard that I could not even add fertilizer and was forced to invest in an Reverse Osmosis unit, my plants and I are both glad those days are over.

Mike

Well I was going by a weight calculated value (which I botched, oops). You made me curious though, so I tested it myself. One level tablespoon of epsom salt added to one gallon of water increased the TDS by about 1100 ppm according to my meter. That would be 110 ppm Mg since epsom salt is 10% Mg. I think I'd still start with a 1/4 teaspoon per gallon dose.

Not sure why we got such different results with the TDS meters. Oh well.

My meter has not been calibrated for a while but it must be accurate because when I test RO water I get very conductivity. I think I will still adjust and recommend using a lower dose of Epsom salts from now on.

Mike

Renee, I meant to comment on how beautiful your Orchids are...Wow!! Those are such gorgeous blooms! Thanks for posting!

Kemistry, I'm really not sure why I add the Fish emulsion and kelp...but I have always had very good luck with both of them and just figured I would add a little to my Foliage Pro...so far I've been very happy with it...I only use half strength of FP...1/2 tsp per gallon of water so I figured a little Fish fertilize wouldn't hurt it. I also decided to cut the Fish down to 1/2 tsp per gallon of water because the smell is so bad, lol...at this amount the smell doesn't last nearly as long.

Howdy!

Foliage Pro 9-3-6 user here, too.
This particular formula has simplified my life considerably.
I use it for all my plants - indoor and outdoor - from citrus to maple, conifer to horsetail,
birch to oak, willow to olive, succulent to hot pepper, pachira, palm, and beyond.

Josh

Josh,

I seem to see you on every forum I look at. You must grow one of everything!

Hey! Yes, I do grow quite a few varieties! ;-)
Four Hoyas, one Orchid, lots and lots of succulents and other houseplants....
I also dug up a Fig this year, so if you're ever at the Fig Forum you might see
me there, too. I grow Japanese Maples, Oaks, Birches, Osage, Citrus, and a few
Conifers - Cypress, Cedar, Redwoods, Pines, and Cryptomeria being some of my favorites.

And that's to say nothing of my vegetables....I'm a Hot Pepper enthusiast!!!

But I digress....

Josh

Thanks for the info, puglvr1! :)