Serrissa Foetida leaves turning black-HELP!

lakemaligne · White Belt Joined: 04 Apr 2008 Posts: 5 Location: coventry

Hi every one,I bought my wife a 4 year old Serrissa Foetida bonsai for xmas,which looked in good shape.It lives on a window sill in the toilet which does not have a radiator,so the room stays at a constant 65 degree's.It gets good light but not direct sunlight.It has a humidity tray and gets watered once a week.I fed it with Chrysal liquid fertilizer(4-6-6) about a month ago and one week later half of its leaves turned black and fell off.Tiny buds are now just struggling through but the plant is looking a little peaky.Some of the leaves which did not fall off have grown quite large and I was wondering if I should snip them off.Can some one please tell me what caused this ,was it the wrong type of feed,or ratio of nutrients.I have stopped using it until I get some feed back from you guys.which type would you recommend please.
Paul

Stymie

I wouldn't blame the fertilizer although you are right to discontinue feeding for now. The large leaves are the tree's way of trying to make the most of inadequate light I think. In addition to supplying a better light source, the watering should be a little more frequent. Serissa are a tad on the thirsty side. It was an unfortunate choice of starter material and a notoriously difficult tree to keep happy. If it expires (an arguable possibility), replace it with one of the figs (Ficus) which are much less temperamental.

lakemaligne · White Belt Joined: 04 Apr 2008 Posts: 5 Location: coventry

Hello Stymey, So you are putting the black leaves down to lack of light.I am puzzled by this because the light from the window is very good.Why would lack of light only effect some of the leaves and not all of them.Can you suggest a reputable fertilizer suitable for my Serrissa Foetida please.
Thanks,
Paul

Stymie

My name is Stymie.

It would be inadviseable to fertilize any tree which is under stress. It will not be able to use feed and any build-up could burn the roots. If and when it revives, any balanced formula diluted to half strength will be okay. I don't know what has caused the black leaves. I said that large leaves or large spaces between them indicate that it is reaching for light.

emorrin

What kind of soil is it in? Most nurseries use plain old potting soil which is not good. Watering once a week tells me that the soil most likely is holding moisture too long. The soil needs to be fast draining. While Serissas like to always have moist soil, they don't like real wet conditions. The leaves turning black is one sign of the soil being too moisture retentive. I have 2 Serissas and if you look at them wrong, they will drop some leaves. They are a very finicky plant. They love ample light, humidity, and do not like to be moved. Once you found a spot where they like then keep it there. I use supplementary lighting (i.e. fluorescent lights) on my two Serissas. The large leaves you mention are a tell tale sign that it needs more light. I have one potted in pure akadama and the other in a turface, crushed lava, pine bark mixture. When I water, the water drains thru the drain hole within a few seconds.

Sounds like two things are needed from the information you gave. 1. A re pot may be needed in better coarser free draining soil. 2. The serissa needs more light.

Dick

There is a stickie at the head of this section of the forum and it may help you with the specifics regarding care of the serissa. It is a difficult tree to grow even though it's sold as being an easy indoor tree. But the black on the leaf tips usually means it'sa under distress, probably from over watering or water quality. If you have very hard water or heavily chlorinated water, you might want it let it set for a day befor using it to water the tree.

lakemaligne · White Belt Joined: 04 Apr 2008 Posts: 5 Location: coventry

Hello Stymie/Emorrin/dick,thanks for replying .We live in a soft water area .The pot has a depth of about 2 inches and I have no idea what type of soil it has,but it only takes about 10 to 15 seconds for the water to drip out the bottom and on to the humidity tray,so does that sound about right.I have bought a bag of bonsai soil from blooms,but am reluctant to repot it in case its one shock too many.Any tips on repotting,time of year/do I wash the roots under the tap like my bonsai book suggests.I am going to borrow a lux meter from work to measure the light reaching the bonsai and then see if there is a brighter window in the house.The room the bonsai is currently in has no radiator but is next to the airing cupboard ,so would imagine its quite dry in there.Also the window is of the frosted type,which I suppose could be effecting the quality of light .The small buds which were appearing have now gone black.and I used to be green fingered.

Paul

emorrin

That frosted window is probably blocking out too much light. The Serissa needs a good amount of light so that looks to be one of your problems. The light meter is a good idea. Put the light meter at the exact spot where you are thinking of putting your Serissa. You will find that the light intensity drops off quite a bit the farther away you get from the window.

It sounds like your soil is fast draining. I still am a little concerned that you only, water once a week. Does the soil still look wet after a full week's time? I water my Serissas every 2 to 4 days. I wait until the top gets dry before I do so. It is easy to tell with akadama because it turns a brighter color telling you it is time to water. A re pot may be in order yet. If you re pot, I wouldn't do any root pruning or washing the roots under tap water in order to cause the least amount of stress.