Large ficus lyrata donated to library in need of rejuvenation

papercarver(z6 MA)March 26, 2011

Hi there:

I am a librarian in a small Massachusetts public library and last winter we were donated a large, rangy ficus lyrata. The tree is already touching our 10' ceiling and consists of two spindly trunks that are supported by two metal rods. The plant cannot hold itself up without them. While growth seems robust at the tips, the leaves closest to the trunk are yellowing between the veins and rusting.

I have reading around this forum and read alot about when to prune and when to repot (plus some potting mixes that I've never considered before) and despite everything I've read, I'm not sure what to do *specifically* for *this* plant and *when* to do it.

Here are some photos of the plant:

The plant is located next to a west facing window in a large sunny alcove. It is watered every seven days, which allows it to be somewhat dry by the next watering. So far I have not fertilized it - am not sure what is best practice for a tree as rangy ans stressed out as this one is at this point.

I would like to prune it such that a)It no longer bumps against the ceiling; and b)it might be better able to support itself.

I am also sure it would benefit from repotting (have no idea if it has been repotted in the last decade!), but have never attempted such a thing with a 10' tall multi-trunked tree.

Any and all advice would be greatly appreciated.

thanks, papercarver

Here is a link that might be useful:

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tapla (mid-MI z5b-6a)

It definitely needs repotting. The interveinal chlorosis might be nutritional, but it looks more characteristic of foliage that is in the process of being shed - ie the plant is translocating pigments & nutrients out of the leaves for use in other plant parts.

Here is what my thinking is:

If you prune it back now, you'll be pruning it back to already compromised foliage that is likely to be shed in the near future - not a good move because it leaves the tree unable to make it's own food.

If you REALLY want to rejuvenate the tree, I'll help you, but anything you do, other than a full repot, is only going to give the tree a temporary lift. Actually, I just left this piece (below) from one of my other posts on another forum here. Read through it, please, for an illustration of the difference between a repot and potting up. If you do decide to repot, I can give you step by step instructions, starting with what to do now, so you can have the tree back on track by summer's end. If you decide to go forward, we can talk about suitable soils and a fertilizer regimen the tree will respond well to.

The timing of certain procedures is closely related to energy management, which gets too little consideration by most growers tending trees in containers. Because repotting and root pruning seem to be most misunderstood on the list of what it takes to maintain trees that will continually grow at close to their genetic potential, I will include some observations about those procedures to open the discussion.

I have spent literally thousands of hours digging around in root-balls of trees (let's allow that trees means any woody plant material with tree-like roots) - tropical/subtropical trees, temperate trees collected from the wild and temperate nursery stock. The wild collected trees are a challenge, usually for their lack of roots close to the trunk, and have stories of their own. The nursery stock is probably the closest examples to what most of your trees are like below the soil line, so I'll offer my thoughts for you to consider or discard as you find fitting.

I've purchased many trees from nurseries that have been containerized for long periods. Our bonsai club, just this summer, invited a visiting artist to conduct a workshop on mugo pines. The nursery (a huge operation) where we have our meetings happened to have purchased several thousand of the mugos somewhere around 10 - 12 years ago and they had been potted-up into continually larger containers ever since. Why relate these uninteresting snippets? In the cases of material that has been progressively potted-up only, large perennial roots occupied nearly the entire volume of the container, plant vitality was in severe decline, and soil in the original root-ball had become so hard that in some cases a chisel was required to remove it.

In plants that are potted-up, rootage becomes entangled. As root diameters increase, portions of roots constrict flow of water and nutrients through other roots, much the same as in the case of girdling or encircling roots on trees grown in-ground. The ratio of fine, feeder roots to more lignified and perennial roots becomes skewed to favor the larger, and practically speaking, useless roots.

Initial symptoms of poor root conditions are progressive diminishing of branch extension and reduced vitality. As rootage becomes continually compressed and restricted, branch extension stops and individual branches might die as water/nutrient translocation is further compromised. Foliage quality may not (important to understand) indicate the tree is struggling until the condition is severe, but if you observe your trees carefully, you will find them increasingly unable to cope with stressful conditions - too much/little water, heat, sun, etc. Trees that are operating under conditions of stress that has progressed to strain, will usually be diagnosed in the end as suffering from attack by insects or other bio-agents while the underlying cause goes unnoticed.

I want to mention that I draw distinct delineation between simply potting up and repotting. Potting up temporarily offers room for fine rootage to grow and do the necessary work of water/nutrient uptake, but these new roots soon lignify, while rootage in the old root mass continues to grow and become increasingly restrictive. The larger and larger containers required for potting-up & the difficulty in handling them also makes us increasingly reluctant to undertake even potting-up, let alone undertake the task of repotting/root-pruning which grows increasingly difficult with each up-potting.

So we are clear on terminology, potting up simply involves moving the plant with its root mass and soil intact, or nearly so, to a larger container and filling in around the root/soil mass with additional soil. Repotting, on the other hand, includes the removal of all or part of the soil and the pruning of roots, with an eye to removing the largest roots, as well as those that would be considered defective. Examples are roots that are dead, those growing back toward the center of the root mass, encircling, girdling or j-hooked roots, and otherwise damaged roots.

I often explain the effects of repotting vs potting up like this:

Let's rate growth/vitality potential on a scale of 1-10, with 10 being the best. We're going to say that trees in containers can only achieve a growth/vitality rating of 9, due to the somewhat limiting effects of container culture. Lets also imagine that for every year a tree goes w/o repotting or potting up, its measure of growth/vitality slips by 1 number, That is to say you pot a tree and the first year it grows at a level of 9, the next year, an 8, the next year a 7. Lets also imagine we're going to go 3 years between repotting or potting up.

Here's what happens to the tree you repot/root prune:
year 1: 9
year 2: 8
year 3: 7
year 1: 9
year 2: 8
year 3: 7
year 1: 9
year 2: 8
year 3: 7
You can see that a full repotting and root pruning returns the plant to its full potential within the limits of other cultural influences for as long as you care to repot/root prune.

Looking now at how woody plants respond to only potting up:
year 1: 9
year 2: 8
year 3: 7
pot up
year 1: 8
year 2: 7
year 3: 6
pot up
year 1: 7
year 2: 6
year 3: 5
pot up
year 1: 6
year 2: 5
year 3: 4
pot up
year 1: 5
year 2: 4
year 3: 3
pot up
year 1: 4
year 2: 3
year 3: 2
pot up
year 1: 3
year 2: 2
year 3: 1

This is a fairly accurate illustration of the influence tight roots have on a woody plant's growth/vitality. You might think of it for a moment in the context of the longevity of bonsai trees vs the life expectancy of most trees grown as houseplants, the difference between 4 years and 400 years, lying primarily in how the roots are treated.color>

Good luck! Let me know if you would like more help.


    Bookmark   March 26, 2011 at 10:40AM
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papercarver(z6 MA)

Hello Al!

Thanks for the detailed response. Yes! I'm up for a true rejuvenation of this plant, beginning with a repot.

I should mention that I am coming to this task as a person with more experience with outdoor shrubs and trees (thus as someone who used to a shrub/tree's mass being greater *beneath* the ground than above it). Your explanation about perennial roots vs. feeder roots makes sense to me (it's basically what I take into consideration when "balling up" a shrub for transplant). What I get hung up on here is the idea of repeatedly root pruning and yet maintaining a healthy canopy above-ground (since rule#1 when transplanting a shrub is to lop off a large amount of above-ground branches to compensate for the root loss of transplanting). Bonsai obviously work, however, so I'll get over it.

Actually, I'm very curious to try this because I have a ficus benjamina of my own at home which would probably appreciate the same treatment. It started out as an 18" tall potted plant that I bought at the supermarket in 1985 for my college dorm room and is now a well-rounded 6' specimen (would have been at least 2' taller now but for some severe pruning on my part).

I am COMPLETELY with you in terms of the importance of energy management: obviously this is critical for the care and wellbeing of outdoor perennials as well. But outdoors it's much simpler because you simply follow the cues of the seasons (I am in Massachusetts - the seasonal cues are EMPHATIC, to say the least). However, with what are basically tropical plants in an artificial environment, I'm entirely stumped as to when to do what.

All that said, I would greatly appreciate your step by step help with this plant. From what you say, now is not the time to prune (although should I maybe pinch the terminal buds since the tree has reached the ceiling?).

So my next step is the repot. My first question is do you have a suggestion of what size pot I should be getting? The current one is definitely too small, regardless of any root pruning I might do, as the weight of the canopy makes it tip over. Also, will this pot be the "final size", to which I will trim the roots over the years to fit?

Thanks very much for any advice, and thanks again for your thoroughness.

michele a/k/a papercarver

PS: Don;t know if this will be relevant, but I have no idea about this plant's previous care other than the owner had it for at least a decade and was fairly obsessed with fertilizing it (when donated to us she insisted we fertilize it regularly - something I have not done, since the pot has no drainage holes and there were salts visible on the soil surface when we got it).

    Bookmark   March 27, 2011 at 12:30PM
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tapla (mid-MI z5b-6a)

Well - thank you for the vote of confidence. ;o) I have easily more than 30 perfectly healthy Ficus in various stages of development in my collection, so I am intimately familiar with there care. I do often put on workshops for bonsai clubs, and sometimes for other garden-related clubs that want to have a fun workshop where you build your own bonsai. Lets get started - the first part is easiest.

You'll need to be sure there are drain holes in the pot. Move the plant to a spot where you can thoroughly/repeatedly flush the soil - saturate the soil and let it rest for 10-15 minutes, then run or pour room temp water through the soil to flush out accumulated salts. Use a volume of water equal to the pot size & flush the pot 5-10 times - the more the better - you can't flush too much.

It's certainly very root bound, so I don't know if you CAN over-water. I'll let you be the judge of that. If you think there is potential that after flushing, the root/soil mass will remain wet too long, then it would be to your advantage to set the plant on newspaper or other paper for a while. The newspaper will act as a wick and quickly 'pull' excess water from the root ball.

After you've done this, return the plant to its pot and fertilize with a half-strength recommended dose of a soluble fertilizer. I heartily recommend Foliage-Pro 9-3-6 because it has ALL 12 essential nutrients plants normally take from the soil, including Ca/Mg, both normally absent in other fertilizers. It ALSO provides most of its N in nitrate form, which helps keep plants compact & full - stronger stems & branches, too. If you can't find it or don't want to bother, use another 3:1:2 ratio fertilizer, like MG 24-8-16 or 12-4-8. If you DO use one of these fertilizers (MG), and it has been more than 1 year since you added any significant volume of potting soil, include 1/4 tsp of Epsom salts per gallon of fertilizer. Potting soils are almost always pH adjusted with dolomitic lime, which also serves as a source of Ca/Mg. At issue is the fact that the Mg fraction of the lime is about 125X more soluble than the Ca fraction. For that reason, soils in their second or third year after planting should occasionally be supplemented with a Mg source if it's not in the fertilizer. This isn't a suggestion to others to just supply Epsom salts to your plants in willy nilly fashion the hope that more is better, because excess Mg in the soil is actually counter-productive. It adds unnecessarily to the EC/TDS (salt) levels of the soil, AND can make uptake of Ca difficult; so eye warily the one-size-fits-all suggestion to "just add Mg" to green up your plants. Understanding WHY and WHEN to add Mg is important if best health/growth is the goal. Sorry for the aside, but this would be helpful for all to understand.

Move the plant back to it's original spot. This may or may not fit with your plan, but it would be helpful IF you think the soil is supporting perched water. If that term is foreign to you, you can read more about PWTs and their effect on plants, as well as How Water Behaves in Container Soils if you follow the embedded link. It will leave you with a sense of how important soil choice is to getting the most out of your plants with the least amount of effort. It's possible that you may even want to make a radical change to the gritty mix, which is what I use for all my trees.

Back to what I was going to say - if you think the soil is supporting perched water, a wick can be very helpful in removing that water. Use this strategy too, if you can't/don't want to depot the plant & set it on paper to dry down (if necessary). Push a wick through a drain hole located through the lowest point at the pot bottom. At the side is better. allow the wick to dangle below the drain hole, but don't let it contact the effluent. This is the part I wondered at - whether or not it would be practical to implement. It would require you lifting the pot above the collection saucer - on bricks or something else nonabsorbent. If that won't work, you should still try to isolate the soil from the effluent so the salts you will flush from the soil each time you water will not be able to make way back into the soil.

Don't worry about pot size - you can easily reuse the one you have, or buy another your plant will fit and try to incorporate the wick in it, If you settle on the gritty mix (I hope you do), you CAN forget the wick, but I always use them when plantings are young as it will drain some of the water from soil particle pores, too.

Tip prune all branches now. It will force the beginning of some back-budding. The plan is to let the plant gain energy * to repot it in late Jun. If you could get the plant outdoors, it would be wonderful for it's health. AFGTER the repot and a short recovery period, I'll have you cut all branches with 4 or more leaves back to 2 leaves. New branches will grow from the leaf axils, When these branches have 4 leaves, cut them back to 2 leaves. This will make your plant very full & bushy. It's how bonsai practitioners build so many branches and fullness into their plants.

Here is a recently repotted Ficus nerifolia (narrow/willow-leafed Ficus), ready to be thinned and pruned when it recovers.

The plant is obviously so compact & full it needs pruning/thinning, but I took care of that AFTER roots were reestablished. If you buy a new pot, or in looking at the one you have, be thinking about some way to mechanically stabilized it (temporarily) so it cannot move (in relation to the pot). This keeps the fine roots from breaking and hastens reestablishment of roots.

All the finer points on repotting can come later, if you remember where you left me. ;o) I'll guide you through that procedure as well. It'll be fun.

That should give you something to think about for a while. Questions?


    Bookmark   March 27, 2011 at 1:31PM
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papercarver(z6 MA)

And so it begins!
Having done a bit of research online I am looking for a source of Foliage Pro that is remotely affordable (as the cost is coming out of my own pocket). To that end, may I ask you how much fertilizer do you estimate that watering a plant of this size will go through in a year? According to the Foliage Pro website, you may add it to every watering for maintenance, at a rate of a quarter teaspoon per gallon. I normally do not pour a gallon of water onto this plant, but I have also not been watering it to flush it out (no drain-holes remember); under the new regime I will be watering it to flush it out, yes? So will I be using a gallon of water per week to water this plant? Sorry to be so picky about the details but I'm trying to calculate how often I'll need to buy the fertilizer (to spring for an entire gallon of Foliage Pro at the outset is too big an outlay of cash for me at the moment).

As for the perched water, while I can't know for certain that this is happening, the potting soil in this plant is ancient and shows very little perlite or vermiculite, so I'm going to assume it's an issue and try drilling a hole into the side of the pot and adding a wick.

Just to clarify: I should not flush the plant until I have the fertilizer ready?

thanks again for your help,

    Bookmark   March 29, 2011 at 11:26AM
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