Pachypodium seedlings going dormant?

[mmcavall]

These are Pachypodium horombense (MG 1963.43) sown October 10th 2016, so they have 5 months now.

Some leaves are getting red/purple/brow and dropping...









My guess is that the plants are starting the dormancy process, because they look healthy otherwise.

But I think it is a little bit early to start dormancy, we are just entering Autumn.

(I dont have any other species that drop their leaves in Autumn/Winter, except for a P. saundersii, which is full of green leaves).

What do you guys think?

Other hypothesis is an effect of mite attack, recently controled, but I dont see any signs of damage in these plants.

[kristian_Fossmo]

Maybe just shedding the older ones? The mites can have something to do with it. Mine dropped a lot of leaves when I had some red mites last fall.
So I have had some issues with leave drops in my P. rosulatum, but when I change the mix to non organic it gave me positive signs of healthier new growth. I will see this upcoming growth period if it hold on to its leaves longer, now when the roots has more oxygen and dry out faster. I don`t now if they hold on to all the leaves the hole growth period anyway? Up here it seems to like the same media as my cacti does. I think I just added a little more pumice in the mix for it when I repotted it.

[mmcavall]

Thanks, Kristian. I'm following your thread and I have read your post when you commented about the P. rosulatum. It was important to me, since I sowed P. rosulatum last weekend, and I tried to use a more coarse and aerated mix.

Maybe you're right about my Pachypodiums, maybe it is related to the mites or to the substrate. Every time I prepare a new potting mix I try to use more mineral, coarse particles, rather then loam, for example, but it is difficult to breake this paradigm. Last weekend I've sown some Euphorbias and Pachypodiums and I prepared a very draining mix, but in the last moment I could'nt resist to add some loam/top soil... I noticed my seedlings are kind of slow, maybe it is because of the mix. Anyway,...back to the Pachypodiums: as I like these plants very much, I could select one of the three brothers to be transplanted to a pure mineral mix and see what happens.

My doubt now is: is it a good season to do that (end of summer, entering fall)? It would'nt be better to wait until Spring?

Thanks for sharing your experience

[kristian_Fossmo]

A tip when you prepare new mixes is to take an empty pot, fill it with the new substrate, way them dry, then water it and way it again. Then you can calculate the water retention capacity. I think I read somewhere (I think it was Iann that wrote it) that about 30% of the dry weight in water retention capacity is good for cacti. So if it ways say 50 grams dry, the sweet spot is 65 when just watered. Then you weigh the pot ones a day until it ways the dry weight again. Then you know how long the mix stays wet and it is a lot easier to establish a good watering regime. My mix that I use holds around 25% of its weight in water and dries out in about 5 days in the 5x5 cm pots, give or take depending on temp. So I know for sure that the pots are dry between a weakly soak in summer. But if you have a lot of organics in the mix, it holds "harder" on the last remaining water, so the plants can`t access it, but stays damp. The smaller the particles, the "harder" it holds water. Clay for example, it can hold a lot of water but not accessible to plants that grows in it.

I don`t know if it is to late to transplant on of the Pachypodiums now for you. Do you have any grow lights indoors? You could put it there for a couple of extra weeks if the weather gets to dull for them. Just to prolong the growth period some...? Would be interesting to se if there is any difference in growth between the mixes if you transplant only one. They do grow in harsh environments in nature.

[kristian_Fossmo]

Found it it a sticky. viewtopic.php?f=25&t=11498

[mmcavall]

Hi Kristian, I know this thread, it helped me a lot when I was starting (if you scrool down you will find my posts). I understand the "rules", but preparing a soil-less mix is hard for me: I have to try each time with less soil, because I have ever grown plants on soil, not on stones. Being a Portuguese speaker makes it hard, because I'm not sure about the terminology: what do English speakers really mean by "pure mineral mix", for example? Pure clay is pure mineral , but is not good for cacti. So I'm trying now some mixes that are "pure little stones" (equals to pure grit? pure gravel? ...not sure....in Portuguese, the word is "cascalho" ou "pedregulho". I would'nt believe it is possible to grow a plant on "pure pedregulho", until I tryed myself and I must say I'm very surprised with the good results).

So , back to the Pachypodium seedlings, do you think I should try transplanting one of them in a "pure little stones mix" like that one in the picture below?


(this is not a top dressing, the whole pot has this mix; do Pachypodiums like that kind of mix? I have the impression they would suffer a little)

About being too late to transplant it: I dont think it is too late, but Pachypodium is one of the few plants I have that really go dormant in winter, so I would wait next growing season. But probably it is not late, since the adult one is rampant now, no signs of dormancy. Anyway, winter here is not dull, to the contrary, it is dry. Temperatures decrease a little and days are shorter, but not dull.

Thanks for having this conversation! I 'll probably try transplanting it next weekend, and hopefully I'll have something to share

[kristian_Fossmo]

The stones in the pot is "gravel" to me. Grit is also "little stones" but just smaller sizes really, after grit you have sand. I like to mix up the sizes some, so the mix I have it is sizes from 1-8 mm. You can go a little bigger as the plants grow I presume. But this is how I have done it and it works for me for the seedlings in the small pots. As you probably have seen, people do different things with good results all over so...
I understand that getting rid of the dirt is difficult, because plants grow in dirt....right ?

Regarding your "winter" , Then I should try to repot it and se whats happens.

"Pure mineral" is a media without organic material (dirt, peat, etc...), thats it... But then you have to be weary of the smallest particles in the "Pure mineral" mix also, Steve Johnsons experience on that matter is clear, with the healthier roots in his rinsed mix. So sifting it is a good idea.

This is my mix. The one on the far left is a granit with some Diabase. I have the luxury of that in the wintertime up here, they spread this all around on the walkways so people don`t slip on the icy ground. So I can collect it and rinse it easily. This is what I use for my Pachypodium also. With some bigger granit gravel also mixed in (1 cm), thats because the pot is a little big so I didn`t want it to stay wet for to long.

In the middle you have pumice and on the far right you have kittylitter (Danish moler, some sort of diatomite).

DSC_5159.jpg (273.29 KiB) Viewed 2857 times

I sift out the smallest dusty particles with a tea sift , takes some time, but I don`t mind really.

DSC_5160.jpg (257.89 KiB) Viewed 2857 times

[mmcavall]

HI again Kristian, thanks for the explanation. Now I know what is grit and gravel ...thank you.
So I will mix some grit and gravel and no dirt and see what happens to my Pachy. I'll keep you updated.

[kristian_Fossmo]

Please do Hope it turns out well!

[mmcavall]

Please do Hope it turns out well!

I did it:



Let's wait some months and see how it responds.

[mmcavall]

Updating: The transplanted Pachypodium drop all its leaves and shriveled a lot...I stopped watering during winter and gave up this plant. Spring came and it's brothers grew new leaves...I was hopeless and then, that:



I'm very impressed. It stayed as dead, shriveled, for several months, neglected, and now it is in full growth again.

[williamsii823]

Yes, Pachypodiums can put up with a lot during dormancy. And all of a sudden, bang! they grow like a weed.

[mmcavall]

Yes, William, I'm discovering it now. Another Pachypodium has also surprised me
( viewtopic.php?f=11&t=37556&p=337255#p337255).
Thanks for your comment.