Hi Miraian friends,
i have an old ficus which is ca. 30+ years old and was not treated well for the last ten years. I try to rebuild it as a bonsai now for a little bit more than one year. At the moment (during winter) he stands in my living room with one side to a south oriented window. Additionally i hang up a red/blue LED plant lamp 1 meter above it and it shines 11 hours from 7 am to 6 pm (see pic below)
In the past few weeks he started to shoot new growth again but unfortunately 80% of the new growth blackens and dies before the leaves come out (see pics)
I realised that most of the new growth which died is on top of the tree. I’m questioning me now if the plant lamp could be the problem. Is it possible that i burn the new growth with a red/blue LED lamp or is anything else the problem? i wouldn’t suspect that the lamp could be a problem normally but the tree got repotted last year in pure akadame an the roots are evolving great so i can exclude any root concerned issues. So what do you think? Lamp? some kind of fungus? some nasty bugs (don’t see any anywhere)
I’m happy about every suggestions. Thank you for your help.
It might be overwatering.
Ficus don’t have a water “shut-off”. They will keep taking up water when they don’t need it, this is called leaf burst.
The cells of the leaf become to full and burst causing the blackened appearance.
What is your watering schedule?
Let your soil dry out before each watering. If there is a tray under your pot, the water should be dumped within 5-10 minutes.
Ficus are very delicate to the environment you give them.
My current watering schedule is every 2-3 days with a room temperature of 23°C. The top of the soil is always already dry to this time. I never had a problem with overwatering but I will try how the tree responds to little less water. So you would exclude the lamp as well as the issue? Why would you dump the water in the tray beneath the tree? The soil don’t has any contact to this water and I always thought ficus love a little more moist atmosphere
I just recently read also that they tends to like dry soil rather…
Out of topic but curious how does akadama work for ficus as you mentioned it?? Im just about to repot mine due to gnats all over the pot but have no idea what soil is the best for indoor one. Thought of akadama but would like some confirmation as Im about to learn ab this type of plant.
I’m totally happy with akadama. I can see a tremendous root growth in this first year but I have to admit that the tree was in in the old soil for 10 years or more so I think it would love every type of soil at the moment
The reason for dumping the water out of the tray is so there isn’t any water left to take up. Remember that ficus don’t have a water “shut-off”. It may not look like the water in the tray isn’t affecting water uptake, if the water touching the bottom of the pot the water column is complete, thus pulling water back up through the soil substrate.
Will that pot fit in your sink, if so, water it 2-3 times, let it sit there for 15-30 minutes, then place on the tray.
I don’t believe the light is doing any harm, you could always turn the tree 90 degrees every week so it receives light all around.
I hate to go against the grain here, but the only times my ficus (4 different species, 6 different trees) do that is when they are hot and dry. Are the tips dry and crisp, or soggy?
You mentioned that you water every 2-3 days and the soil is dry when it’s time to water again. How deep into the pot does it dry up? Is the whole pot getting water everytime you water? Do the leaves “perk up” shortly after you water? The water that is left in the tray, how fast does it evaporate after you water? Does the bottom of the pot touch the water in the tray for more than a few minutes?
I wouldn’t think the LED is giving off that much heat to cook the new foliage, but does it feel considerably warmer under the light? Are the older leaves yellowing at the tips?
You mentioned that the new growth lower on the tree is mostly fine. Have you tried reducing the brightness of the lamp, or reducing the amount of time that it’s on? Do you use this type of lamp on any other tree?
I know I’m asking a lot of questions, but a ficus in akadama is going to be hard to over water. Especially if the soil is drying between waterings, like he said it is.
The fact that some of the new growth lower on the tree is fine, also tells me that it’s not something that is affecting the whole tree, but only the top.
Depending on how much the soil is drying out between waterings, I’m going to say that it’s either not enough water, that lamp is too intense for the new growth on top of the tree, or maybe a little of both. Hope to hear back from you and best of luck.
Hi @el_cheezer thanks for your detailed answer.
At the beginning they just start to blacken and after 1 or 2 days the tips are completely dry and crispy.
I would say the first 0.4 inch of the soil is dry when i water again and i water till it spills out from the bottom so normally the whole pot should get water.
I don’t see any change of the leaves. They don’t “hang” when the soil is dry and don’t change after watering.
The pot stands with 3 feet in the tray and the tray has a slightly curved bottom so the pot never stands in the water. I always stop watering when it starts to pour out of the bottom so there are only, let’s say 10-20 mL of water in the tray which evaporates in 1-2 hours.
I don’t feel any temperature differences under the light only if you touch it and i don’t see any yellowing or anything else on older leaves. Just the newer leaves has some brown spots (see on the second pic above)
I have turned off the lamp now as the hours of sun start to become longer, so we will see if the lamp is the issues. I don’t use the lamp on any other tree except another ficus but he stands beside this big one and doesn’t get this much light from the lamp
So it seems like it could be too much or too less water. We will see how the tree responds. I will try 2-3 weeks watering it a little bit less and see if anything changes and then try the other way.
Thank you so much for the answer. I think the new growth was drying out. Ficus like humidity, and I think the mixture of being indoors and the lamp were making it hard for the new growth.
If you do water less, watch the tips. If they start to wither and die back, you’ll know it needs more water. Best of luck!
I only have two ficus so am not as experienced but I have used a LED grow light on them and from my own experience it is very unlikely to be anything to do with the lamp. Looking at the photo it is 50-100W? and you say it is around 1 meter over the ficus. I would be surprised if it is much effect.
I have been using a 1000w grow lamp around 30cm over one of my ficus which was newly bought and feeble from being kept inside at the nursery. Because I was lazy and didn’t acclimatise the ficus to the lamp I burnt around 20% the older established leaves. The exposed parts of the leaves turned black and after a few days they dropped off. However the new shoots and leaves were not affected in any way and after about 10 days the burning and leaf fall stopped and the ficus became very vigorous under the lamp with lots of new growth.
Having said that as long as it is close to the glass in that south facing window with day length increasing it shouldn’t need the grow lamp now.
I also thought that new shoots turning black was over watering but I have never seen it so can’t be sure. With poor growth there will be less water uptake. The pot looks fairly deep so I would allow the top inch of soil to dry out before watering. The tree will tell you if you are under watering because a few leaves will yellow and start to fall and this will be an ongoing process.
Ficus do like humidity but I have found they don’t need it. My two are sat in south facing windows in a room with strong central heating for around 40% of the day and a log burning stove and 1 is growing strongly and the other is just recovering from being repotted a couple of weeks ago.
I’m pretty sure too that the lamp isn’t any problem. I used this lamp now already for over two months so it would be very untypical that the burning starts now.
We will see if the tree responds better to less water or to more. Until now i don’t panic, the old leaves look all good and just the tips blackened. I think the tree will recover very quickly as soon as i know what i did wrong.
You must be careful with the fertilizer that you use in the ficus. The leaves have a burn aspect due to excess systemic fertilizer. Excess salinity can burn its foliage. I work many species of ficus here in the tropics, Puerto Rico, but I have not had experience with LED lamps.
Thanks @josorl, i don’t think that the fertilizer is an issue at the moment because i haven’t fertilized the tree since September. I wanted to start with fertilizing this month again but the salinity could be an issue perhaps, because i have to use tap water which is very hard in our region.
Me again. I found out that i have a spider mite issue as well on the ficus. It isn’t that intense till now (see at the end of my finger tip) but nearly the half of the foliage has some of them.
I am wondering, can they be the reason for the blackening of the tips? I never saw them on the tips, only on old leaves but i don’t know if they can cause the blackening even when they attack other leaves. Anyone any experience?
You can use Bayer Liquid “One Year Tree & Shrub”. I use this on all my ficus. Can Found in Home Depot
Thank you, i already sprayed with an insectizide and they are getting less but do you think the mites can cause the blackening on the tips as well? Normally i wouldn’t expect this.
If that picture is pretty consistent about how many mites you have, I doubt they would be causing the black tips. They may be aggravating the problem, but I don’t think they are causing it.
@SkeiL , which insecticide, and what concentration?We’re you spraying before the tips turned black?
Indoors tree, other plants nearby? Are they bugged?
@el_cheezer i think as well that the mites aren’t the reason for the blackening but wasn’t sure.
@KurtP i am using this insecticide: Insecitizide
I sprayed only after the tips were blackening so it cannot the be the issues and i already used this spray in the past, didn’t harm anything. One other ficus was standing right next to this one but i already put it aside and it has no mites and no blackeing of the tips.
Btw, i watered the tree less now for the last 1-2 weeks and no other tip blackened but i have to admit that i have no endtip left on the top of the tree. Anyway, the tips on the side are doing quite well and i hope that the tree will grow new tips at the top soon. So it looks like the whole issue was really only too much watering. I’m really surprised by this because the soil drys out so fast (it is dry after 2 days latest) but it seems to be so.
I can never keep my winter / indoor ficus wet enough…
By April, it usually looses most of its leaves. Put it out after temps get over 40F at night, and the bugs have their way all summer… I inherited the tree from a bonsai buddy, so I feel I have to keep it going…
Not my favorite tree for bonsai. Fairly easy to grow…?
Never had a tip problem.