Question about feeding sick bonsai

MoSinister

I have a friend who has been watering a couple of bonsai (fukien and some other indoor/tropical tree I can't identify...looks kinda like a money tree?) with only Superthrive and watering them only once a week. They look underwatered and potentially starved at this point.

Obviously, the major issue is to first correct the watering routine so that the trees are getting watered when they need it...not on a schedule. But I don't know enough about bonsai to know if it's harmful to the plants to give them a shot of regular 'ol 8-7-6 Miracle Grow liquid plant fertilizer at this point. They are obviously weak.

He has been using Superthrive on them from the start. Now, I don't want to start a conflict on this product, but does anybody on this forum use ONLY superthrive to "feed" their plants?

Thanks,
Mo

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rockm

For all its hype, Superthrive never says it is a fertilizer or "plant food." It advertises as a plant "growth enhancer." Even its manufacturers don't recommend what your friend is doing. IT IS NOT A REPLACEMENT FOR FERTILIZER. It was never intended to be. This misconception is common though.

Cease using the product. Don't feed the sick plants anything--plants are not animals and cannot be fed into healthiness. Usually sick plants have deficient root systems that are incapable of absorbing nutrients. Adding fertilizer to sick roots is like throwing more wood on a dead fire. It does no good.

Simply leaving the plant alone-aside from making sure it get adequate water --not too much or too little--in a bright humid spot is about all you can do to help revive a sickly tropical now.

bwaynef

At what point does a sickly looking plant, that is sickly looking because its lacking nutrients, get fertilized?

I guess another question mine is begging is how do you tell a tree that is stressed and sickly looking because of lack of nutrients rather than ....other reasons?

WF

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Will_Heath

I agree completely.


I must disagree here. If a plants roots can not absorb nutrients then it really doesn't matter if they are present in the soil, however if the plants needs nutrients and they are not present, then you have serious problems. Remember that in a natural growing environment nutrients don't leave the soil because the plant is sickly.


This is correct and should be taken into consideration with my statement above. Many people will kill a weak plant by trying to "save" them by over-watering, overfeeding, etc. Treat it as if it was healthy, water only when needed and don't dump the feed on thinking it will bring it back to life. Water, feed, and place as normal...this will give the plant the best chance of recuperating.


Will

Brent

Good question.

I don't run with the crowd on the "Never feed a sick plant" myth. It is much more complicated than just feeding usually.

First, an underfed plant most likely needs Nitrogen, and that symptom is a general chlorosis, or even yellowing of mostly older leaves. Nitrogen is the first depleted element because plants need a lot of it and it is not retained in the soil very well. It is a 'mobile' nutrient; the plant will move it around to where it is needed the most, usually the growing tips, thus the yellowing of older leaves.

Nitrogen deficiency can be confused with a root zone problem, because the symptoms are very similar. When the roots are compromised, they have difficulty taking up nitrogen. I find the best way to tell the difference is to unpot the plant and examine the roots. Healthy roots will be firm and light brown (usually) with a few white growing tips. Declining or rotted roots are blackish and soft with no white tips. Unpotting can also tell you a lot about your soil and your watering practices. Unpot when you think the plant needs water. If you are right and it's a healthy plant (albeit underfed) the roots will be dryish and solid. If you are wrong, chances are the roots are in decline and you are going to be very surprised to see that the roots below the surface are sopping wet, black, and soft.

If the roots are healthy, just feed it, if it is an appropriate time of the year. There is little point in feeding deciduous plants this time of the year in the N Hemisphere since winter is approaching. Indoor or greenhouse tropicals can be feed, or given a rest period. Feed them when you want them to grow strongly again. This may depend on your area, lighting, humidity, and heating. If a plant is dormant or resting, as in the case of tropicals, a few months without added nutrients isn't going to make any difference.

If the roots are compromised, my advice is to repot it, even if it is a tropical and repotting isn't really timely. Declined roots means it has been overwatered, but unless you are using a stable and completely inorganic soil, chances are about 100% that the organic portion has collapsed. If this is the case, it is going to be very difficult to monitor the water, and I think it is best to give the plant a fresh start in fresh soil. For tropicals, this may mean stimulating them into a growth period to recover even if it isn't timely for other reasons. In other words, more heat, light, AND fertilization.

Now we come to the controversial part. I always feed after repotting. I have saved hundreds, if not thousands of plants by repotting and feeding simultaneously. There just isn't any good evidence that feeding them is going to cause problems. There are a few fungal diseases that thrive in high nitrogen environments, but there are other fungi that thrive in low nitrogen environments. The purpose of the repotting is to correct the soil/water/air environment to make it less conducive to ANY pathogen, mostly by increasing aeration and lowering water retention. If this has been corrected, then the next step is to encourage the plant to grow (if the season and other factors are appropriate). You don't do this by restricting nutrients. You maximize the nutrients, light, heat, etc up to a safe and appropriate level. For deciduous plants during the growing season, this will usually mean light cool shade, but knowing the growth characteristics of the species is very important. There usually isn't any need to feed again until the plants show signs of growth, but as soon as you get any shoot growth (as opposed to just leaf buds opening), it's time to return to a normal fertilization regime.

Brent
EvergreenGardenworks.com
see our blog at http://BonsaiNurseryman.typepad.com

mike_p

IMHO, Superthrive is vastly overrated. It's only value is as a nutritional supplement, if your bonsai feeding program dosen't include sufficient trace elements. As a stand alone nutrition program it's worse than useless because it causes the user to believe that proper feeding is being given the plants when in reality they are starved.
If your fertilizer has the proper NPK and trace element balance, then you can forget Superthrive. I did, years ago.

Mike

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rockm

"If a plants roots can not absorb nutrients then it really doesn't matter if they are present in the soil, however if the plants needs nutrients and they are not present, then you have serious problems. Remember that in a natural growing environment nutrients don't leave the soil because the plant is sickly."--Will

"Now we come to the controversial part. I always feed after repotting." Brent

I erred on the side of caution in the "don't feed a sick plant" advice, as beginners usually don't "get" what they're doing when they fertlize a plant. The common thought for many is they're providing some kind of sustenance for their plants. They have forgotten plants make their own food and they're only providing the means for the plant to recover and not the fuel for its recovery.

most beginners are also learning how to give proper BASIC care to bonsai. The intricacies of helping a bonsai recover form their over (or under)care are usually not in their playbooks yet. Most overfertilize, over or under water and over apply Superthrive on their trees. An overfertlized plant's soil is a big problem, just as overwatered or oversuperthrived soil is.

Just leaving the plant alone is preferable, in my opinion, to advising a newbie to go ahead and fertilize their plant as it recovers. That means they're going to be adding liquid fertilzer with more water, or futzing around with some mysterious "organic" voodoo mix like bat guano and ST and not allowing the plant to simply heal itself.

It's another excuse to "nurse" a plant back to health. Nursing usually spells disaster for such plants.

mike_p

Now we come to the controversial part. I always feed after repotting." Brent

It gladdens my heart to see that an expert horticulturist such as Brent feeds after repotting. I've been doing this for years,contrary to "accepted conventional wisdom", or some such bs.
Not only do I feed after repotting, I feed before repotting as well. My repotting regimen goes like this. Remove tree from pot. Immerse roots in tub of water and water soluable fertilizer such as Miracle-Gro NPK 10-50-10 at half strength dilution. Prepare pot. Wash excess soil from roots. Trim roots as necessary. Install tree in pot. Place fertilizer pellets just below soil level. Water until any fines left in soil are flushed out and water runs clear from drainage holes.

Mike

__________________
Bonsai is not a hobby.
Bonsai is a way of life.
MP@BBB Studio

There is no way to happiness. Happiness is the way
Gautama Buddha

Will_Heath

And to think I was crucified for saying that I fertilize my collected trees after potting them...


Air, water, and food.

Important to plants and humans, take away one and it's kaput.


Excellent thread!


Will