Brown aerial root tips on Brassavola

[j_orchids]

...debating whether to post this in beginner discussion or here.

This photo is of brown tips developing on these longest aerial root tips of my Brassavola.



I'm trying to take better care of my plants, and I have been lightly misting the roots of this plant daily with distilled water, and it has really responed. A couple of weeks ago I switched to using distilled water with 1/4 teaspoon (1.15g) of Schultz Orchid Food per gallon (as recommended on the container). Schultz is 19-31-17 with 13.4% urea nitrogen. I believe that comes out to about 58ppm total nitrogen (please check my math).

Are these brown tips a sign of a problem? How do I correct it? All of the other live roots look healthy.

Thanks!

~Jon

	Mistking Looking for a misting system? Look no further. Automated misting systems from MistKing are used by multitude of plant enthusiasts and are perfect for Orchids. Systems feature run dry pumps, ZipDrip valve, adjustable black nozzles, per second control! Automatically mist one growing shelf or a greenhouse full of Orchids. See MistKing testimonials

[estación seca]

In my experience brown tips are a result of low humidity or staying dry too long. It can be tricky to water a plant with lots of overhanging roots in a low-humidity environment; the wanderers need to get wet frequently, but you don't want the medium staying wet. A lot of people mist the wanderers with one or two spritzes from a spray bottle every day or so.

Your math is good:
First Rays Nitrogen Management Calculator

[j_orchids]

Originally Posted by estación seca

In my experience brown tips are a result of low humidity or staying dry too long. It can be tricky to water a plant with lots of overhanging roots in a low-humidity environment; the wanderers need to get wet frequently, but you don't want the medium staying wet. A lot of people mist the wanderers with one or two spritzes from a spray bottle every day or so.

Well, that's good to hear, I guess. This plant was last purchased in, perhaps, 2009. It has survived in spite of my neglect. I just started paying more attention to it, and it has put quite a bit of new growth. It is on the window sill above my kitchen sink - that window has constant condensation on it with the cold weather, so it's probably the most humid spot in my apartment. I had been misting the roots twice a day, but cut back thinking that was too much. I don't think there's anything I can do to increase the humidity. It sounds like maybe this is just as mature as the roots are going to get in my care before dying back? It has a ton of brand new roots on it since I have been misting it once or twice a day.

You don't think the use of fertilizer is to blame?

~Jon

	Mistking Looking for a misting system? Look no further. Automated misting systems from MistKing are used by multitude of plant enthusiasts and are perfect for Orchids. Systems feature run dry pumps, ZipDrip valve, adjustable black nozzles, per second control! Automatically mist one growing shelf or a greenhouse full of Orchids. See MistKing testimonials

[jkofferdahl]

I doubt it's fertilizer, unless you're using it extra strong and applying it to dry roots (Secas raices, eh?). Estacion has, I think, nailed it; I've experienced similar root issues on mounted Brassavolas and raising humidity took care of it.

[estación seca]

Brassavolas do fine with lower humidity than most other Cattleya alliance plants - or orchids, in general. Lucky choice. The main problem with them is giving enough light to bloom them.

You can dampen roots hanging in the air as soon as they dry out. Most people don't wet them towards evening so they don't sit cold and wet through the night, which some people think invites rot.

The fertilizer dose you're using shouldn't be a problem, but what water are you using? Your utility will have a water quality report available online. Brassavolas prefer total dissolved solids (TDS) under perhaps 400-500 parts per million (ppm.) Some orchids must have even less. Your fertilizer will add some to your water as well. My city water has 800-1200 ppm TDS so I collect rain water, and use reverse osmosis water when that runs out.

I think if you spritz just the exposed roots they will continue to grow a bit.

People sometimes hang some Spanish moss (Tillandsia usneoides) on the exposed roots of orchids to keep the humidity up a little.

[j_orchids]

Originally Posted by jkofferdahl

I doubt it's fertilizer, unless you're using it extra strong and applying it to dry roots

The nitrogen concentration I am using is 58ppm. It's mostly urea - I heard this is bad. It is mixed in distilled water, and I am applying it to dry roots.

Originally Posted by estación seca

Brassavolas do fine with lower humidity than most other Cattleya alliance plants - or orchids, in general. Lucky choice. The main problem with them is giving enough light to bloom them.

B. nodosa was recommended to me by a grower at the very first orchid show I went to. I got that plant to rebloom in an unobstructed west window, but the humidity was pretty low in that apartment too (I think). That plant later died after being moved to Ohio and servery neglected. I like that they will survive significant periods of neglect (something I am prone to doing) and can still recover. Also, I love the scent.

Originally Posted by estación seca

You can dampen roots hanging in the air as soon as they dry out. Most people don't wet them towards evening so they don't sit cold and wet through the night, which some people think invites rot.

Okay, that's what I was doing, but I thought it was maybe too much, since I understand these to be "drought tolerant". I figured they like to be dry for longer than a few hours.

Originally Posted by estación seca

The fertilizer dose you're using shouldn't be a problem, but what water are you using? Your utility will have a water quality report available online. Brassavolas prefer total dissolved solids (TDS) under perhaps 400-500 parts per million (ppm.)

I think I said it before, but I am using distilled water or rainwater. TDS should only be based on the fertilizer, so 1.15g per gallon is about 300ppm, I think.

Originally Posted by estación seca

I think if you spritz just the exposed roots they will continue to grow a bit.

That's what I have been doing, but not with pure water - I've been doing this with my fertilizer solution. Above post suggests maybe this is a bad idea? I can up the spritzing to twice a day though, as I was doing before.

Originally Posted by estación seca

People sometimes hang some Spanish moss (Tillandsia usneoides) on the exposed roots of orchids to keep the humidity up a little.

Another great tip! Thank you so much!

~Jon

[estación seca]

Even drought tolerant plants prefer plenty of water - but not too much. It's fine to water again as soon as the roots dry.

What you're doing now should be fine. Plants not in active growth don't need much fertilizer, so you probably don't need to fertilize more than once a month. Start up again when the plant begins making new growth.

[Roberta]

As long as you have all those new roots, you're fine. Older roots do just eventually stop growing. If the environment is very humid, they can get really long, but that just isn't practical in the house. Those new ones look great, the plant will have plenty of root surface to keep itself hydrated. As for urea, much of what you hear about how bad it is is baloney....In nature orchids have to break down nitrogen-containing compounds, so they must have the bacteria in their roots to accomplish that. And they really don't need much fertilizer at all. Yours is quite dilute, and that is excellent. One thought... the fertilizer that you're using has a high middle number - phosphorus, which lowers the pH, necessary if you are using tap water that tends to be alkaline. In pure water, it may be making the solution too acidic (as well as not providing calcium and magnesium). You could just mix some tap water in to the "soup" when you fertilize. You might invest in an inexpensive pH meter. Aim for a pH of around 6.

[j_orchids]

Originally Posted by Roberta

As long as you have all those new roots, you're fine. Older roots do just eventually stop growing. If the environment is very humid, they can get really long, but that just isn't practical in the house. Those new ones look great, the plant will have plenty of root surface to keep itself hydrated. As for urea, much of what you hear about how bad it is is baloney....In nature orchids have to break down nitrogen-containing compounds, so they must have the bacteria in their roots to accomplish that. And they really don't need much fertilizer at all. Yours is quite dilute, and that is excellent. One thought... the fertilizer that you're using has a high middle number - phosphorus, which lowers the pH, necessary if you are using tap water that tends to be alkaline. In pure water, it may be making the solution too acidic (as well as not providing calcium and magnesium). You could just mix some tap water in to the "soup" when you fertilize. You might invest in an inexpensive pH meter. Aim for a pH of around 6.

This is all great info! Thank you! I have been using the fert. in distilled water, but it contains no Cal or Mag. I do have a cheap pH meter, but I'm not sure it's working.

So the deal with urea is that it doesn't hurt the plant - it just might not be available for the plant to use? If I'm just using the fert. to mist the roots and then letting the plant dry, might that lead to a harmful buildup of "urea salts" or something that go unused. Maybe I am over thinking this.

This I know about my water: TDS was 52ppm this month as reported by my utility, but they don't break down the constituents. Fluoride is 0.72ppm. I read that fluoride can harm plants. That's why I switched to using distilled water. Should I just go back to using filtered tap water with the fert. that I have, assuming that the urea and fluoride are no big deal and the 52ppm TDS provides enough Cal and Mag to keep the plants happy (my filter does not remove TDS)?

Oh, also, my utility also reported pH 8.5 for my water source this month.

~Jon

[estación seca]

You water TDS are great for almost all orchids. You can use small amounts of fertilizer intended for pure water with your tap water when fertilizing. You have no need to use reverse osmosis nor distilled water.

You don't need to use distilled nor reverse osmosis purified water unless you take up growing Phragmipedium or some cloud forest orchids that demand very pure water.

If you use a fertilizer with Ca and Mg and correct your pH you probably will not need to supplement. The amount in your tap water might be adequate if the pH were corrected and might be too low. Neither ion is absorbed well at pH 8.5

The fluoride is not a problem for plants.

The pH is higher than ideal. If you use a fertilizer formulated for use with pure water that will at least partially correct the high pH.

Urea is used by at least most orchids. Older information is incorrect.

Yes, if you fertilizer regularly, about once a month you should rinse the roots well with your tap water.