Vanda Royal Blue?

[Dorra]

I bought this Vanda as Vanda Royal Blue. And she has bloomed blue in previous years. But look now ... splendid flowering, but something is not right. I first thought she was going back to one of her parents ... but no one in pedigree resembles this color. Has she been sold with the wrong label?

[Paphluvr]

How many times has it bloomed blue in the past? Just when you bought it? I don't know if it's done in Sweden, but in the States vendors frequently dye the flowers, particularly Phals. Afterwards they bloom in their true colors. Could that be what happened with this plant?

[Roberta]

If it has bloomed blue for you before (after you have had it for awhile), have the growing conditions changed? Like perhaps less light, or a change in temperature? I have seen considerable color variation in my Vandas from year to year, but this is pretty dramatic. Some other species are really sensitive to the pH of the water/fertilizer though I don't associate this phenomenon with Vandas, more like terrestrials.

[Dorra]

Paphlurv:
This is the 3rd time it blooms since I bought it... both precursors were flowers blue. And no ... they was'nt dye. I am sure of that.

Roberta:
I have the same growing condition. Outside in the shadow house in the summer and now on windowchill under the artificial light. Temperature are more or less the same. I use R/O water and RainMix. This spring, however, I fertilized with Iguana Blom.

[Roberta]

Originally Posted by Dorra

Roberta:
I have the same growing condition. Outside in the shadow house in the summer and now on windowchill under the artificial light. Temperature are more or less the same. I use R/O water and RainMix. This spring, however, I fertilized with Iguana Blom.

Ah ha! If the fertilizer was on the acidic side (the "bloom blooster" fertilizers tend to be), and you had been using a balance fertilizer before, that could do it! When you are using RO water, it doesn't take much fertilizer to shift the pH. I think RainMix is designed for pure water and gets it right. Go back to the fertilizer you were using before, and it's very likely that your flowers will go back to blue.

[Dorra]

Thanks Roberta

---------- Post added at 07:27 PM ---------- Previous post was at 07:12 PM ----------

Iguana Juice Blom
N .................................................. ....4,0%
P .................................................. ....3,0%
K .................................................. ....6,0%

Contents: fish emulsion, krill extract, yucca, seaweed powder, lucerne extract
2,0%.............................................. ... brewer's yeast
0,4%.............................................. ... B-1 (Thiamine Hydrochloride)
0,3%.............................................. ... B-2 (Riboflavin)
0,4%.............................................. ... B-3 (Niacin)
0,3%.............................................. ... B-5 (Pantothenic Acid)
0,2%.............................................. ... B-6 (Pyridoxin)
0,5%.............................................. ... B-7 (Biotin)
0,8%.............................................. ... B-12 (Cobalamin)
2,0%.............................................. ... Chlorophyll (lucerne)
0,1%.............................................. ... Alfin (lucerne)
1,3%.............................................. ... Arginine (seaweed)
1,6%.............................................. ... Clycine (seaweed)
2,2%.............................................. ... Carotene (lucerne)
0,9%.............................................. ... Serine (seaweed)

[Roberta]

Probably the phosphorous (in relation to the other "major" components.) What's the formula ( the NPK is what counts) on the Rain Mix? RainMix I am pretty sure is specifically formulated for pure water. Fertilizers designed for tap water (which is usually a bit on the alkaline side) have the phosphorous to balance that.

I just would not have associated a Vanda as being that sensitive to pH... where I live, people adjust pH on Hydranges to get blue (neutral-alkaline) or pink (add some soil acidifier) on purpose. Interestingly, Thelymitra (Australia terrestrial, many intense true blue, not coerulea) tend to go the opposite way... some will come out pink if not grown acid enough, intense blue on the acidic side. So it does appear that the pigment in this Vanda is pH sensitive.

[Dorra]

RainMix:
N ............. 11,8%
P2O5 ........ 2,7%
K2O .......... 13,7%
CaO .......... 11,8%
MgO .......... 3,5%
SO3 .......... 4,8%

This Vanda has 50% sanderiana, 43,75% coeruela, 3,13% dearei and 3,13% tricolor... wonder which is so sensitive...

[Roberta]

Originally Posted by Dorra

RainMix:
N ............. 11,8%
P2O5 ........ 2,7%
K2O .......... 13,7%
CaO .......... 11,8%
MgO .......... 3,5%
SO3 .......... 4,8%

Yessss... lower Phosphorus relative to the other constituents. The other components probably tend to balance themselves out. If you have a pH meter or pH paper, test the fertilizer solution mixed up at the correct level for plant-watering.

Most tap water has some dissolved minerals, so the bit of fertilizer you add doesn't change the pH a lot (buffering capacity) RO water doesn't, so it's important to get a mix that keeps the pH in the range that orchids want (typically, some place between 5.0 and 6.5) So you want to stick to a formulation that is designed for it. (So-called "bloom" fertilizer really doesn't do much for blooming, you can accomplish the same by reducing nitrogen - just just use less fertilizer - in the winter. In the spring, the plant is growing rapidly and needs more)

[Dorra]

But Iguana Blom and RainMix both has less F in relation to the others! Therefore, I do not understand. I have EC and pH meters and keep the pH lower than 7 all year

I don't think that fluoride (F) has much to do with anything, it would be present, if at all, at very low levels in any fertilizer. It's the three major constituents (their balance, and also the "other ion" for each that make the difference. Also, with that bloom mix, you are not getting the calcium and magnesium that's in the RainMix either, and those are important. I suspect that they're balanced with other things (such as the sulfate) that keeps them neutral. The other constituents won't have much, if any effect on the pH of the solution.

Do test that bloom fertiilzer mixed for "delivery" with your RO water. I suspect that its pH is a lot lower than you expect. (Lower than 7 is great, lower than 5 may give you results different than you expect) But again, the absence of calcium and magnesium may also be factors. Without knowing exactly which component does what, I do think that you have definitely messed with the chemistry with the fertilizer change - which could affect color. Not bad,just not blue.