Need help with rescued Vanda (yellowing leaves, poor roots, watering)

[xDannyS_]

Hello everybody, this is my first post. I rescued a Vanda from someone a few weeks ago. He got it in good condition from a nursery but didn't take proper care of it. It was held in terrible conditions - very little light, barely watered, never fertilized.

It was originally in a small plastic basket with 95% of the roots hanging freely. I switched it to a wooden basket with coco fiber. The reason for this is that the roots don't seem to hold any water. With the plastic basket, they would dry out completely after just 40-60 mins even if I soaked them for many hours. I water by putting it in a bucket of water. Now with the wooden basket, the roots stay hydrated for 3-4 hours.

Right now I fertilize it every 10 days by spraying the leaves until they are very visibly covered. I also spray a little bit on top of the coco fiber. I don't really spray the roots, maybe a little bit by accident.

When I got it, one of the middle leaves already started to yellow. Eventually, it was completely yellow and fell off. Now, as of a week, I noticed that there is yet another leaf at the same height but opposite side that is starting to yellow. I'm not sure why :/

The top 2 leaves are stuck in mid-growth it seems. The newest one is fully closed still, while the 2nd newest is closed halfway. They haven't grown at all since I got it.

Despite all of this, the Vanda has grown a spike since I got it. It's also producing happy sap on the spike. I have it under a strong high quality grow light which it seems to like.

So my questions are:
- What's going on with the yellowing leaves? Could this be from root damage that happened when I was transporting it to my home or switching it to the wooden basket? From what I could tell, only 1 got damaged. It was a very brown and brittle root, but I could tell it was still alive (even if barely) because it was slightly green inside.
- How do I properly water this Vanda? Right now I dunk it in a bucket for 10-15 mins it in the morning and then again 3-4 hours later when the roots are dry again. By the late evening, all roots are fully dry again, including the basket and the fiber. Is this ok or am I watering it too much/little?
- How can I get the roots to recover and hold water for longer? How can I get new ones to grow? None of the current roots have those tips that look like silicon caps
- How do I fertilize correctly and how much? My fertilizer is 5 (N) - 3.3 (P) - 5 (K) - 0.55 (Magnesium). It says 2.5ml per liter for phals, and 1.25ml per liter for 'hung orchids'. I've been doing 2.5ml on a liter and then spraying the solution.

P.S The pics are from before the first yellow leaf fell off. So the yellow leaf you are seeing is the first one. The new second yellow leaf can be seen by itself in the second last picture.

Thanks for the taking time to read this long post.

[Dimples]

I don't grow vandas so I'll leave the specifics of care to those that do, but plants are significantly better at absorbing nutrients through their roots.

Foliar applications of nutrients are less effective than root delivery, and there is still some scientific debate on if it is effective at all, to what degree, and which nutrients are able to be effectively delivered by leaf application. It also depends on the plant, some plants have thick cuticles others don't.

There's also the issue of regularly wetting the leaves potentially leading to rot if conditions are cool, the plant doesn't dry off quickly, or if there's an existing infection or there are damaged areas where pathogens can take hold.

If you wish to continue with the foliar feeding that's up to you, but it will be a good idea to also apply the fertilizer solution to the root system. Use the diluted fertilizer water in the bucket when you soak the vanda instead of plain water. Once a week would be plenty and less frequently would be fine for a recovering plant.

The NPK numbers look good but the fertilizer doesn't have calcium (important). Unless your water source supplies it the vanda and any other plants you're using it on will suffer deficiencies over time.

If your water source lacks calcium, you can supplement with a calcium fertilizer or use up the fertilizer you have, then look for a fertilizer that has all of the micronutrients in addition to NPK. I use DynaGro Foliage Pro (NPK is 9-3-6 and includes all micronutrients) but there are many other suitable fertilizer options. You'll need to check what's available in your country. No need to special order anything from abroad.

[Roberta]

First, Welcome!

Rapid drying of Vanda roots is normal, and what they need. The wood basket with coco fiber will help to maintain more humidity around the roots, but still let them get the wet-dry cycle. There are enough good roots to keep the plant going... be patient since growing new roots may take several months. I agree with Dimples, foliar feeding is pretty useless. The cuticle on the leaves that helps to protect the plant from desiccation also make the leaves pretty impervious to water. Concentrate on the roots You may lose a few more leaves, don't worry, just keep the plant hydrated, it should recover nicely.

[estación seca]

Welcome to the Orchid Board!

It doesn't look too bad. What are your growing temperatures? Most Vandas do best with warm to hot days and intermediate nights.

I'm not sure what caused the yellowing. Sun that far north is rare and weak in winter, but if it had been kept in poor light, then put into a sunny window, it could have burned.

I think you are watering properly for the plant, basket and medium. They need watering at least once a day unless potted. Underwatered Vandas develop fine linear wrinkles parallel to the length of the leaves.

I agree foliar feeding of Vandas is useless. Vandas are heavy feeders, more than most other orchids. I suspect your plant isn't growing because it isn't getting enough fertilizer. A Vanda nursery in Florida, Motes Orchids, waters their plants every morning, and again in the afternoon on hot days. Motes describes fertilizing at every 5th watering with fifteen (15) ml, 1 cooking Tablespoon, of powder in 3.78 liters (1 gallon) of water using 13-5-8 fertilizer. In the past they used 20-20-20 with good results, too. They say a properly fertilized Vanda should have a pale green zone of new growth at the base of emerging leaves that is 1cm in width.

Your conditions are not as good as south Florida so you could use less, but I would still fertilize every 5th watering. The amount you're giving now is tiny compared to this recommendation.

You can subscribe to the Motes Orchids E-mail newsletter and get monthly information about growing orchids. It is written for Florida, but you will still learn a lot.

[Clawhammer]

Nothing to add except that you have done a nice job re-hydrating your vanda. The before and after is pretty dramatic. "Orchid rescue" is a term I rarely use but it applies here. Kudos