Pachira Aquatica - leaves dropping and my grow-lamp

Hello,

This is a question regarding my Pachira Aquatica tree - see the
following pic :
http://picasaweb.google.co.uk/tjrundy/Plants#5422110226768198770. I
got it back in June, and it's been shedding leaves ever since. In the
summer months it's wasn't too bad after it stabilized, but then in the
recent months it's been loosing a branch of 6 leaves a week -
sometimes 2 per week.

Sadly it's becoming a former glory of itself, which is shame cause
it's a really cool talking point in my flat, and I love it. So much so
that I thought some additional light might help. Remembering my
friend's from university 'grow up', I bought a sodium floodlight which
is on from 4am to 7am, and then 9am through to 6pm.

I did some cursory research after wards and read that halide lights are
better than sodium lights as plants have a better reaction - I was
always taught that orange was the best colour because it was absorbed
most by green leaves. However it seems that the colour temperature has
a bearing on the efficiency of the photosynthesis...

My flood light's about 75W - is that strong enough, or is it not going
to make any difference? Would a 150W halide bulb work better? Since I
installed the lamp about 3 weeks ago, I've not noticed any reduction
in the rate of drop-off.

I think I'm sadly resigned to the fact that my flat is just too dark
(no direct sunlight except in Summer for an hour) to support such a
plant, even though they are advertised as being low light plants.

I don't think the leaf drop-off is due to over / under watering - the
planter has a bed of gravel and I keep that wet to aid humidity, and I
spray the plant every week or so (I travel a lot so I'm not actually
here that much). I let the top of the soil dry before watering - again
- typically every week. The flat's warm all year round.

Any advice?

Thanks in advance,

Tom.

 

Hi Tom

I am afraid that I have no knowledge of Pachira aquatica, but I do have a box in which I grow plants under lights.

I suspect that the lack of light could be the cause of your problem. Outside light levels are often much brighter that we realise, because our eyes and brain automatically compensate. In my box I have three 3 ft fluorescent tubes, with a total power of 90 watts, illuminating a growbag tray. And it's all enclosed in a box with white walls. This turns out to be an excellant level as I can get plants to grow happily and flower in it in mid winter. By contrast your light level is less, especially if you take into account the distance from the bulb. My plants are within two inches of the tubes, and the light falls off sharply with distance.

There is much talk about growing wavelengths. My understanding is that plants need light in the red and blue range. But Sodium lamps are sold as growing lamps, and I think there is a fair amount of tolerance. A halide bulb would have a better wavelength profile, but will give out a lot less light that an equivalent wattage sodium lamp, which is very efficient.

My feeling is that you have to keep it in proportion. As a low light plant, you are giving it quite a bit of light - though I would ensure the light was aimed at the leaves. To give it more would be quite expensive. Really you are only trying to keep it alive until spring not trying to make it think it is summer, and some leaf loss may be quite normal. I have a number of larger plants, such as a tree Fushia, F arborescens, which is not hardy. This is in my hallway, where the light level will be as low as yours without the lamp. These plants have to like it or lump it until the spring comes.

 

Hi Tom and welcome to GC.

Gosh, how jealous am I of your Malabar Chestnut tree! I have had mine for several years now and it's only 1/2 meter tall, in fact hasn't grown at all. Sadly, mine is not a braided one. I could only dream mine was as yours.

As to the leaf drop, mine is outside in a sheltered situation with morning and early afternoon sun only. Although it is said they are evergreen, I have lost all the leaves on mine every year ... in saying that, it still has its leaves now so maybe this year it will retain them. They regrow quickly with warmth.

My only suggestion is the warmth aspect but I cannot vouch for that. Did the supplier give you any instructions?

Here is a link which may help ...

http://www.gardenology.org/wiki/Pachira_aquatica

Good luck to you ... I would be devastated to lose that after such a short period of time.