Please tell me why my Cestrum nocturnum is doing this?

Hi, I bought a night blooming jasmine about 4 weeks ago. On the first day the leaves got all droopy on me after I repotted, but they quickly bounced back once I watered the plant.

However, after about 2 weeks some of the leaves are getting............curly? Not curly from the tip, but from the 2 sides. Looks like a canoe.
And only about 1/3 of the leaves are doing this, most of it being the leaves on the top. A few random leaves on the lower part are now also curly.
I have researched on the internet and am getting opposite answers to under/over watering or under/over fertilizing.

Since I do not have much experience.........quite confused.

It's blooming fine although it did lose a lot of flower buds after repotting (but I assume it's due to shock since there are now some new buds forming).

I am kind of worried about the leaves curling though.
May someone tell me what is really going on here?

I have been watering with a soluble fertilizer (instruction says to add every time I water) every other day until a little water seeps out from the bottom (it's in an air conditioned building so quite dry).


Thank you!


Ivie

This message was edited Oct 6, 2009 7:52 PM

I think leaf curl can be caused by a number of things from water, to soil, to light conditions. The leaf color on your plant looks good but if you are watering every other day and using fertilizer each time you water, that sounds like way too much to me. How much light is the plant getting? I think Cestrum need quite a bit of light, possibly a few hours of direct sun.

I hope someone more knowledgeable with this particular plant will pop in with some advice but I have a feeling the problem is too much fertilizer and water.


http://davesgarden.com/guides/pf/go/2128/

I would definitely check on your watering--to see if you really need to water or not try sticking your finger down a couple inches into the soil and see how wet it feels. If the air in your building is dry it'll make the very top surface of the pot look dry fairly quickly, but down an inch or two it could still be sopping wet which would not be good for this plant. I'm also not sure that you need to be fertilizing that often, most of my Cestrum's are in the ground but I've grown some in pots for 6 months or so waiting to plant them and didn't fertilize them anywhere near that often and they did just fine. Usually fertilizer burn will show up as burnt looking edges on leaves and I don't see that (at least yet) but I don't think it needs that much.

Whether or not you can fertilize @ each watering depends on a combination of three things - the strength of the solution, the speed (how fast it drains) of the soil, and your watering habits. Personally, those plants I over-winter indoors get fertilized with a weak solution (about 1/8 recommended strength) of fertilizer every time I water, roughly every 2-3 days, but I grow in very porous soils and I water so at least 1/5 of the water I apply exits the drain hole after percolating through the soil. If you aren't fertigating (fertilizing + watering) in this manner, you risk a high accumulation of soluble salts in the soil and a drought response from the top of the plant - no matter how wet the soil is. With too much water in the soil, or too much fertilizer, the plant response is the same - a drought response because the plant cannot properly take up water.

It seems that your plant is unable to take up enough water to keep the distal ends of some of the foliage turgid, so the leaf tips are wilting. From the information you provide, I would say the probability is very high that it is the result of either a high level of salts in the soil from over-fertilizing (plasmolysis), from over-watering, or from a combination of both. Take note of how leaves look early in the AM as compared to late afternoon/early evening - see if they are more turgid in the AM. It's also likely that you'll see the emerging symptoms of necrotic leaf tips and margins soon, if you don't correct the problem ASAP.

Al

Thank you all for your suggestions!

The plant gets about 2 hrs of direct sunlight and then bright indirect light for the rest of the afternoon.
It's morning right now and I don't seem any difference in the turgidity of the leaves compared to last night.

I agree that it's probably over watering with fertilizer.

So I am going to do the following:
-stop using the fertilizer (at least until the leaves return to normal)
-water less frequently, I am thinking every 3rd day instead of every other day. (and yes, I will check the soil moisture with my finger. I have actually been doing this but I only do it down about 1inch so perhaps deeper)


Thanks again, I really appreciate the help.


Ivie

There are actually some other remedial things you should do asap. E.g., you should flush the soil thoroughly & then unpot the plant & let it dry down. Let me know if you want a step by step or would prefer to follow your own options.

Al

Al,
Flush the soil and dry it?
Could you explain it more? Yes, I would like a step by step guide please.


Thank you,

Ivie

I would saturate the soil completely and allow it to rest for about 10-15 minutes to allow accumulated salts to go into solution. I would then flush the soil several times with a volume of room temp water at least equal to the volume of the container the plant is in. After it stops draining, I would unpot the plant & set it on newspaper overnight or until the soil is just damp, then return it to its pot. While the soil is drying down, add a wick to the bottom f the container. Allow that wick to dangle below the pot each time you water until water no longer drains from the wick. I would use Miracle-Gro 30-10-10 or 24-8-16 as a fertilizer. If you suspect or know your water is quite alkaline, I would add an ounce of vinegar to each gallon of irrigation water to help neutralize alkalinity, which will help the (suggested) fertilizer acidify the soil.

If the leaf distortion is only in the new leaves, you might be seeing a deficiency of one of the immobile nutrients - perhaps Ca or one of a couple micro-nutrients that can produce distortion in foliage, but there's not enough information to support anything other than a possibility. Getting back to the subject of Ca ..... what did you use when you repotted (soil)? I'm trying to determine if there is a possibility of a Ca deficiency that could account for the distortion in emerging foliage.

Al