Ficus Issues...

We have large Ficus here at my work that has been here at least 7 years. One other time (a few years ago) I had problems with it dropping its leaves - some plant food in the next few waterings took care of that. For the past couple of weeks - it's had some yellowing of some of it's leaves - which then drop. Each day I come in there seems to be more. It has plenty remaining but it concerns me that this is happening "out of the blue." Any insight anyone?

Your tree should just be stirring from its winter rest and thinking about putting forth a little growing effort. Was the tree recently rotated in its spot, so another side faces the light? Has it been subject to drafts or periods of chill - during a move, construction, etc? Reduced light? Are you allowing it to dry down between waterings - there's no one else "helping" you water? - watering with coffee, soda, etc? When last repot? Last time fertilized? Are leaves evenly yellowing or showing signs of interveinal chlorosis before falling? Are primarily older leaves falling? If so, and you've ruled out watering issues, suspect mites or a deficiency of one of the mobile nutrients - N, K, or Mg. Tough to tell from here. ;o)

Al

Al,
Thank you - great advice. Unfortuately...he's not been moved and I'm the only one that takes care of him. He's quite large and has been in this pot for about 2 years - plenty of room for him to still spread out. I tried the fertilizing thing when I first noticed the leaves dropping...about 2-3 weeks ago. There's no consistancy re the leaf age...new ones...old ones...doesn't seem to matter. I brought my daughter's digital camera (doesn't take great pics, unfortunately) in & took a pic...not sure if that will help at all.
Chantell

This message was edited Mar 10, 2006 11:48 AM

Send me an e-mail & I'll send you an article I wrote about Ficus b. as a handout to a bonsai group I did a workshop for.

The pattern of yellowing isn't consistent with an insect problem. In saturated soils that drain poorly, low oxygen levels cause iron and manganese to become electron acceptors. This leads to their precipitation (iron and manganese) and, even though these elements might be present in soils, the plant’s inability to assimilate them. So, if you've ruled out over/under-watering (symptoms are nearly the same - both actually cause leaf loss, a drought response), I think you should look to a nutrient shortage. You said you fertilized 2-3 weeks ago? With what - do you remember? The plant won't "turn around" this time of year in two weeks, so I would wait awhile before getting too much more concerned. Likely deficiencies are Fe or Mg. If it was a plant other than Ficus, we could look to emerging leaf color to tell if it was the relatively immobile Fe that was short (yellow emerging leaves can indicate Fe shortage, but new Ficus leaves are yellow - light green anyway, so an unreliable indicator). A Mg deficiency can be relieved by adding an appropriate Epsom Salts solution or by adding dolomitic lime, which also adds Ca to soils.

Another possibility is a drought response due to a build-up of water/fertilizer salts in the soil. Plasmolysis (aka fertilizer burn) can occur in soils that are not flushed regularly by applying good volumes of water at each watering. A high concentration of salts in the soil can cause reverse osmosis, which actually "pulls" water from plant tissues in the same manner that curing salt "pulls" water from bacon or ham. Plants can die of thirst while roots are awash in a sea-of-plenty.

Better pics might help, but there's really no substitute for a hands-on assessment. I hope something I said rings a bell.

Al

Dear Chantell . . . Your Ficus benjamina in its native habitat of central Thailand is an epiphite. It roots in the crotch of other trees then sends its roots to the ground. It needs airation, high humidity and it cannot withstand "not growing" Keeping it through the winter is risky and this is the result. Air conditioning and central heating will stop groth. Fertilize sparingly with half strength liquid or not at all in winter. The soil in your pot looks fresh . . How can that be, if you say its been there for two years. The kind of pot you have it in with a tight dish on the bottom offers the plant no air and no drainage. Lift it up and put few handfulls of pebbles there to seperate pot from dish. If it is convienient , keep a spray bottle nearby to mist it till summer weather, then it must go outside in bright shade. Logos

Logos...thanks for the suggestions...I can do everything but move it outside. Our office is on the 2nd floor and that plant has been there longer then I...which equals out to 7+ years. It was potted up about 2-3 years ago. But I'll get a mister in there and something to raise it up some.

I am no expert, but I have been told that ficus respond by loosing leaves to ANY change..i.e. change in weather, change in how the light hits it, so on and so forth. I had a ficus that was very tempermental at one point and was apprehensive about getting another after loosing the first. Now I have a new one and it does wonderfully where I have it..I did just put in a new window in between ficus' though, so that might be why the new one is doing so well. sorry I cant help more. Abbie

Ficus defoliates readily in the face of some cultural conditions that move toward adverse, but not when cultural conditions are improving. I commonly see lots of information on forums that parrot the fact that any changes cause defoliation in Ficus species. Not true. Ficus defoliates in response to temperatures decreasing, to drought (or over-watering, which causes the drought response as well), or to decreasing light. When temperatures are on the rise, light are levels increasing, or watering regimens are changed to something more appropriate, Ficus responds with improved vitality and a greater abundance of leaves, NOT defoliation. Trees that are already growing in low light conditions can, however, defoliate in response to rotating a part of the tree grown in good light to lower light. The side that faced a light source can defoliate when rotated away from the light.

I have watched these responses in about 30 of my trees that cover some 8 or 9 species of Ficus, year in and year out. Additionally, there is no founding in the physiology of tropical Ficus to support this commonly held belief.

Most Ficus, including the common benjamina, elastica, and microcarpa, all prefer full sun but willtolerate shade to varying degrees. Alii, lyrata, and pumilla are a few that prefer a little protection from afternoon sun.

Al

So if I put my ficus b. in the southern window in the winter, I dont have to move it before summer? I am worried that the leaves will burn if I dont move it out of the window.. I would take a pic but my cam doesnt work right now to my knowledge. thanks for the info.

Your window will cut out at least 25% of available visible light, which is roughly equivalent to bright shade outdoors. The limiting factor with most Ficus in indoor sun is not light intensity. If the soil temp goes much above 90* (easy to do if the plant is near a heat source or the container is in direct sun) root metabolism slows dramatically, creating problems. Decreased air flow around leaves also lowers humidity in the layer of air that contacts leaves (sun warms leaves - leaves warm surrounding air so it will hold more moisture, lowering humidity), which closes stomata and slows photosynthesis. So, even if you cannot raise humidity, air movement will help.

I have about 15-18 Ficus b. I grow as bonsai or potensai (potential bonsai). I don't suggest you treat your plants this way, but mine are under lights and grow with good vitality all winter long, so they tolerate the defoliation well. When I move the plants from my basement grow area to my full sun grow benches, I do not have the time or inclination to acclimate them to full sun (you should do this, however). I unceremoniously plop them on the benches where they quickly burn and defoliate. Within a week - 10 days, a new flush of growth will begin that will self-acclimate to full sun as it emerges. I find this to actually speed development of the plant.

In situ trees spent their entire lives reaching for the sun. They grow horizontally or vertically to the brightest light source. When they break through the forest canopy or reach the forest edge, the tree really comes into its own and begins to grow with a vengeance.

So - yes, gradually move your plant to full sun but be careful to do it over a couple of weeks. Get it outdoors as soon as you can - when night temps are reliably above 55*. Most grower's indoor Ficus are stressed during the winter & low on energy reserves, making them vulnerable to defoliation. Make sure the pot temperatures do not rise too high & your plant will be fine.

An aside: Misting houseplants makes the plant tender feel good, but does nothing for plants. Anecdotal parroting across the net supports the it while anything written from a scientific perspective pooh pooh's the practice. In fact, there is lots of evidence that misting closes stomata very quickly and it often takes many hours for the photosynthetic mechanism to return to normal. From this, it is more logical to draw the conclusion that misting is probably closer to a detriment than a benefit.

Thats the view from here.

Al