artyanimal

Mike,

Take the following with a grain of salt as my trees are outside in lots of sun and in normally hot humid conditions. I apologise in advance that as such, this will be a lot for you to read while I don't really know what parts (if any) will apply or be useful to you:

As you may know, natural raintrees grow on shorelines in sandy soil and in full sun. My reaction to this for years was to pay more attention to the soil's particle size than its PH levels. As I also had little or no info on this plant, I reasoned that sandy = fast drainning and mixed approx 70% inorgainic (30% turface and 40% lava rock) to about 30% orgainc. I repot at least a month before Florida's spring starts in early March and as it turns out this guess at a soil mix was not bad as it does not restrict drainage, availability of air or the roots in any way. As a resutl, I usually had enough time for two feedings of a low nitrogen liquid orgainic fert to assist roots before sping growth started (about a month) and I returned to my normal 10 - 10 - 10. Expolsive healthy growth always followed.

Invariably though, and despite continued feeding, by early summer the leaves always lost thier darker green color and began to look paler and washed out. The compound leaves while moslty green almost always showed more than a few on each branch with two, three, or more individual leaflets turning yellow. My solution was to always reduce full sun exposure to morning only which did improve the appearance of new growth but, did not really return them to their initial spring-like color and did not fully stop the yellowing leaflets.

I finally determined that since other shoreline plants like buttonwoods seem to like an occasional dose of magnesium (which is part of the chlorophyll in all green plants) that I would give that a try. It works very well and the plants stay greener into the summer but, the reality is that this remains more of a cause and effect type remedy. In other words, this may suffice for you as you can keep healthy raintrees this way but, I (being me) was not entirely satisfied. Come to find out the fert I was using with high potassium after repotting was probably "holding" the magnesium in the soil and making it unavailable to the plant. So, for me, with harsher Florida sun, it was back to the drawing board, sheesh!

My latest procedure in its third season is to add a little lime in the organic part of the mix and then to apply a root boost tea instead of the fert after repotting. BINGO! Evidently, the tea and the lime (which does make soil less acidic) provides the needed magnesium more freely. While I do not know the exact PH level raintrees prefer, my best guess would be at around 8 or 8.5. This tea and lime approach may not apply to you as I mentioned earlier in this thread. Low nitorgen ferts will help your trees roots and trunk as I said especially since your lights or sun may not be quite so harsh or depleating on your trees.

With regard to flowering on older growth. I can tell you that raintrees in Florida respond very well to hard pruning and tend to pop out almost everywere. So, you can often get new growth on large limbs and even on the trunk that will get you flowers that way. Flowering without pruning however, seems entirely at the trees discreation (if you will) and is really anybody's guess.

One tip that may prove useful is to leave a small nub when pruning away from the keeper. If you cut to close to a branch or twig you want all at once, you could lose it even with cut paste. Its much less risky to clean up the stump in a few months or even next season.

Cheers,

Arty

Mike423

Thanks arty, I found pretty much everything you had to say useful. I've had my rain tree for not quite a year yet so I'm still new to its needs and preferences. Shortly upon purchase I repotted the rain tree in a mixture containing Turface, Fir bark, Haydite, and limestone adding a little dirt from it previous mixture (not disturbing the root ball). Hopefully the lime stone in the composition will have a similar effect of adding some actual lime (though probably not as well)?? Most of that soil composition was due more to availability though than what I would have liked it to be comprised of. I just purchased some red lava rock and was planning on repotting the tree again in before summer with equal parts lava rock, Turface, and fir bark with maybe a small amount of non porous rock like haydite, or gravel. I'll have to see if I can find lime stone somewhere though seeing as it seems like it will be a helpful component maybe replacing the Haydite or gravel with it. Getting it before was just out of coincidence so hopefully I can find some though I'm not sure where to look. Also have you found this tree has any sensitivity to being bare rooted/root pruned when repotted (thought I'd ask as I know some trees that do)?

I noticed myself twords the middle/end of this past summer that my rain trees color was beginning to fade as well as the few yellow leaf brackets here and there. I also keep my tree in partial shade protecting it in the afternoon during summer when its outside as it can get really hot some days in my area. Do you think Chelated Iron would be a good substitute to the lime, or would that be something better given in addition with the lime? I was thinking of maybe starting to add two treatments of Chelated Iron and seaweed extract to my trees this summer to see the effects.

As for flowering, what type of fertilizers do you use (0-10-10/10-10-10 etc..) and in what type of schedule do you apply them to get the best flowering and overall health for the tree? I just figured I'd ask since I noticed you said you fertilize with a 10-10-10 mixture, but my experience is that high nitrogen fertilizers inhibits flower/fruit growth on most flowering trees if not prevent it all together by promoting too much vegetative growth.

Thanks again for the helpful advice, I most likely wouldn't be able to find out nearly half as much without your help.

-Mike

artyanimal

Mike,

Once again, take this with a grain of salt. In this case, epsom salt(s) aka: magnesium sulphate. This is what works for me under more intense sun here in south FL.

Having little or no info myself for years, most of what I do for raintrees is the result of trial and error done in a by comparison fashion (one tree treated one way and another treated differently) and by observation of similar species in nature to select a method for 'best' results. As I said, the notion of a shoreline plant led me to the lime and therefore, magnesium in the soil which is indeed, epsom salts. I fancied there was a certain logic in relation to shoreline and "salts" and must have accidently been right on some level simply because it does in fact, work.

I'm quite sure you are correct however, that a lack of either magnesium or iron will hinder the buildup of chlorophyll we can actually see ourselves as the very pigment that makes leaves green. Again, under my sun exposure, either deficiency is especially unacceptable. Please note that as we were discussing soil mix I did not include chelate as I use it for this species and several others, in a foliar spray. Sorry for the omission, it just happens in this instance to be the way I do soil. In other words, by all means use iron but, not as a substitute for magnesium. I believe both in fact, are fully needed.

Under my immediate (more or less) natural conditions, acacias and powder puff trees which, like the raintree are legumes, thrive in our nasty Florida soil loaded with coral rock, shells, and sand in full sun. This calcium carbonate soil is always alkaline or, having a PH always above 7.0. While neither acacia or powder puff are native, it was this observation of such healthy plants in a 'natural' setting that led me to treat the raintree similarly as a bonsai. Good observational tip for successful growing btw, whenever possible.

As for flowering and ferts...

Here raintrees flower in late spring or early summer. After repotting a month or so before spring starts I use ferts low in nitrogen. I'm not all that fussy. In a pinch after said repotting, you can even use cactus juice which is something like 2 - 7 -7 within as little as a week. For roots and flowering I used to use a 6 - 14 - 8 or some such, in all honesty, because I get it cheap from a nursery supply. Hopefully trying for up to three bi-weekly applications before growth really started to explode. Not always doable for me with many, many trees but, in a perfect world that was my goal. In any event, and under my conditions, I did get plenty of flowers as a result. We evidently differ in this because by the second or third low nitrogen application I did then switch back to higher and concentrated on foliage as I am in a commercial situation and need full looking trees quickly.

Note: Over the last few years due to the eventual summer fading, I have tried using root boost tea instead of ferts after repotting on some trees as I mentioned. I should note then, that while not really as big an issue for me as yellowing leaves, flowering is not as abundant on these. Again, this may not apply as you may not suffer the same level of depletion as I do.

For what its worth also, I do not use a 0 - 10 - 10 fert for subtropical or tropical plants and never have as they do not slow down (or stop) as do their nothern counterparts in winter. I reason also that plants can and do store nitrogen so while they clearly would not need as much in winter, I would be reluctant to deny them all together since plainly, they do still carry out various functions.

Cheers,

Arty

Mike423

Alot of good points. I know my situation doesn't butt up to yours seeing as we are in different climates, but I thought it would be beneficial none the less as I can take your advice and use it as base information twords the study for my own rain tree. Especially seeing as you have a climate setting more natural to this species.

As for fertilizer I wouldn’t use a no nitrogen fertilizer, just an example I had given. I would probably use something more like a 3-10-10 along with some seaweed extract or something similar once or twice in addition to fertilizing during the down months.


As for nutrient deficiencies I guess I'll use magnesium and chelated iron in succession with each other when needed, and or in general applications (having a test period first of course) as a preventive measure in the future. I currently have signs of deficiencies, as the leaves are lighter green with darker colored veins, so I guess now is the time to start . When you said you use a root boost tea after repotting I'm guessing you meant a (watered down) liquid rooting hormone. I myself have done this before but for some reason I just kind of stopped a while back and I'm not sure why?? Probably due to the abundance of trees I have repotted this past summer and the fact that I am already adding other supplements after the repotting process to bring down transplanting stress. I guess I should start using it again though as it will undoubtedly help as well.


I forgot to add, as one final question what time of year do they generally flower for you, some time in spring I'm guessing? Just thought I would ask so I know when to give a the tree a little boost to get ready.

Thanks
-Mike

artyanimal

Using both 'builders' sounds wise to me Mike. As I said, I use one in the soil and one occasionally applied by foliar feeding. In years gone by, I have even been known to keep both white and red mangrove trees not only alive but, thriving entirely out of water as bonsai the exact same way!

Re: Flowering...my BRT flower in late spring or early summer as I said. But, that is a general observation since it does of course, depend entirely on each year's weather. Last year for instance was I guess, a regular spring as I recall some flowering in late May so I'd have to say pretty much right on schedule.

Cheers,

Arty

Mike423

Thanks again Arty.

Mike423

Bought some Magnesium and Iron today and made a mixture including both, which I'm planning on applying as a foliar spray starting today. I wasn't able to get chelated iron, Just regular iron, hope it works as well?? I might end up having to get chelated later though if I see it since its probably more readily absorbed in that form?

I also purchased some superthirve, I know its a long debated subject between some bonsai enthusiasts but I figured I would give it a test run and see how it works as well since I always see it everywhere. Though I assume there isn't too much a difference between superthrive and trace element FRIT which I apply yearly.

artyanimal

Mike,

Superthrive as I understand it claims that vitamin B1 helps stress reduction at 'root level' after transplanting/repotting. Studies by various universities for the most part seem to disagree. Hence, the afore mentioned debate.

I contend that numerous powders (spores actually) for teas instead, containing beneficial mycorrhizae fungi do this job much better by making nutrients in the soil and water uptake easier for the newly repotted (hopefully not to be confused with: dearly departed) plants.

In the end, Superthrive is usually sworn by as a magical exiler by those who do little or nothing for their plants, notice a problem and then try it. They of course, then do see results since doing something in such instances, is better for the plant than previously doing nothing.

I don't believe you fall into this category at all and will probably not see the alleged spectacular and utterly amazing results. In other words, at least its not all that expensive and I seriously doubt it will hurt.

Just my two cents.

On the other hand, magnesium and iron as already discussed here and elsewhere, are essential for chlorophyll production and these clearly ARE needed by all plants.

Cheers,

Arty