International Aroid Society

Definitely keep thinking of Fluoride in your city water. It has ruined many crops of the leafy aroids for nurserymen all over the place. And the person who mentioned the raising pH to help the situation is definitely right. I used to find in nurseries that the plants that remained in one size pot would show symptoms as the media gradually acidified.

Derek

From: aroid-l-bounces@www.gizmoworks.com [mailto:aroid-l-bounces@www.gizmoworks.com] On Behalf Of Theodore Held
Sent: Tuesday, November 11, 2014 12:42 PM
To: Discussion of aroids
Subject: Re: [Aroid-l] leaf burn causes?

Ferenc,

I am probably not the best person to answer your inquiry. But seeing no responses as yet, maybe my words will induce the more knowledgeable members to chime in.

I stopped my Spathes from experiencing leaf tip burn by taking the advice of the late Steve Lucas who indicated to me that he grew his in an almost swamp-like aquatic planting, with the roots continuously wet (that is, soaking in a puddle of standing water). Once I tried his technique all my new leaves stopped having tip burn and they continue to be fully green to this day (five years now). My water is pretty good, being relatively low in conductivity and moderately alkaline pH (in accord with desired municipal practice). I do not fuss with mixtures with DI water or trying to modify the pH.

One factor you might consider would be the relative humidity of the surrounding air. Assuming that wet feet would not be desired for many species, having a low relative humidity might put stress on leaf tips on those varieties with more normal water likes. This might also account for your seeming success at work with problems at home. Just a suggestion.

I also grow Anubias, but mainly in a submerged state. I never have any sign of abnormal necrosis with these. When I have grown them with leaves emergent I have also never had and tip burn or abnormal necrosis. This one is a mystery to me. I also would not exclude the possibility of disease.

Other factors that might be in play are those involved with horticulture taken as a whole: light level, air movement, temperature, environmental variables such as day-night fluctuations. My advice would be to take notes on anything you might think about and compare the environment where you are successful to where you are not.

Ted Held

Detroit.

On Sun, Nov 9, 2014 at 2:40 PM, Ferenc Lengyel <feri.lengyel@gmail=2Ecom> wrote:

Dear Aroiders,

I know that this question is not aroid specific but I know no other forums where I could ask it (and it incudes aroids).

Does anybody know what physiological difference might cause leaf tip in some aroids, but not in others? I have some Philodendrons, a Dieffenbachia cultivar, two different Syngoniums, a Spathiphyllum cultivar, Epipremnum aureum, an Aglaonema and Monstera deliciosa (I had another Monstera with small leaves, but it has died). Of these genera, Monstera, Spathiphyllum and Epipremnum aureum shows leaf tip burn (the tip of the leaves becomes necrotic) followed by necrosis of the whole leaf. Monstera deliciosa is a hard plant to kill, but here in my appartment it can not develop normally, the leaves become necrotic. It applies to Epipremnum aureum, another easy houseplant too. The same might be the situation with Spathiphyllum, but I bought it recently and I mainly watered it with deionized water. Lately I gave it tap water and it started to exhibit leaf tip burn too. I had another Monstera which has perished after necrosis of all of its leaves. On the other hand my Philodendrons, Dieffenbachia, Aglaonema and Syngoniums are not affected at all.

In my aquarium I had Anubias plants which suffered from nercosis of their leaves too. They perished (I used 1:1 mixture of tap water and deionized water).

My non-aroid plants suffering from leaf tip burn include Dracaenea fragrans (necrosis is limited to leaf tips) and Chlorophytums. I have Chlorophytum comosum (again a plant nearly impossible to kill) and a Chlorophytum orchidastrum cultivar (’fireflash’). Both suffer of severe necrosis and loose all of their leaves and die when watered with tap water. When I water Chlorophytum with deionized water (once a month or so with citric acid dissolved in it to lower pH) my Chlorophytums do much better. It is interesting as I read that Chlorophytum comosum is sensitive to fluoride and raising the pH of the water (that is the opposite what I do) helps by decreasing solubility of fluoride ions.

My non-aroids not affected include a Vriesea cultivar (I know that bromeliads should not be watered with tap water but recently I started to do so with no problems) and a Schefflera.

Th pH of our tap water is around 8.0 and that of deionized water is around 5.5. Light levels are low but Monstera deliciosa must not die where Philodenrdons live and grow.

The plants do not suffer from a „bad gardener” as at my workplace my Mosteras florished. There lives the motherplant of my M. deliciosa and it is huge, without any leafburns and the small leafed species (which I lost here at home) grew well without any blackening of the leaves too. Sunburn, under- or overwatering, too heavy soil mix should be excluded (maybe it is not the right word... I mean, do not consider them).

Maybe it is not the water, but I can not think of anything else. Monstera deliciosa and Chlorophytum comosum are so easy plants to grow and make thrive that it is really strange that I can not even keep them alive here at home.

Do you have any idea?

Ferenc

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