I'm confused by the conflicting information from this forum as compared to the dormant period described by Aridlands Greenhouses for their nmaquanum. I'm not getting their plant, but just need information on how to grow these two. They say their namaquanum is a winter growing species. Needing a rest about April - June. Please help, I'm supposed to be getting one of each of these in a trade this week. When do I water & when is it dormant?
I'm gathering it's winter dormant from November - February as I just read a post from someone in Ohio in the plant files. He said it grows from May to October outside. Then He brings it in to the house for the winter. Unless someone has some other advice, I'll use this as a guide.
The basic rule with these and other Pachys is to water (and feed) when they have leaves, but hold back on water (reduce frequency, probably not to zero) when they go leafless. What that means will vary depending on local conditions. It's generally a good idea to water a bit during dormancy so the roots stick around. If you pot up the plants in a rocky mix (say 50% pumice) then you will have a bit more latitude in watering.
You picked two tricky examples from the genus. Those species are harder to keep going than most. If you don't have any other Pachys, you might consider starting with lamerei or geayi, which are a bit more forgiving. P. brevicaule is also available grafted if the normal form proves to be problematic.
Your two plants have different growing seasons. P. namaquanum is a winter grower and goes deciduous in late spring/summer, though sometimes only briefly. P. brevicaule is a summer grower like the rest of the Pachys.
Both plants will grow better with good light (sun). This is particularly important for namaquanum, because it's active during months when the light tends to be weaker. Give that plant as much light as you can during the winter months, put it right by a good sunny window if you're taking it inside.
It's not uncommon for Pachys to lose their leaves after being bare-rooted and shipped. Be careful not to overwater in the beginning and during the adjustment period. The second growing season you can open up the tap and spoil them a bit when they're up to speed.
P succulentum compactum is rewarding and easy. (I like the form sold as compactum better than the species type.)
P bispinosum is also fun and forgiving.
Then P horombense, P drakei, P 'Mandritsara form'.
I'm bored of P lamerei, but the form known as ramosum is the nicest. Sometimes called 'Ihosy form'. Also similar and easy but more classy P geayi or P mikea.
These come up over on the caudiciform forum on Dave's garden, too. Folks there report great luck with a form of container gardening called "Semi-Hydro" using clay hydroponic pellets as medium. I use a gritty mix high in inorganics and I purposely UNDERPOT. (I've lost MORE pachypodiums shortly after repotting than I'd care to admit.)
I refuse to buy P brevicaule, P bicolor, P eburneum, or P densiflorum for a while longer. They die too easily and too often under my conditions. I'm still trying with my third P baronii windsori and my 2nd P baronii. I've killed a couple P rosulatum, but I still have a couple going…for now.
P. bispinosum also has the advantage of flowering prodigiously. Mine makes more flowers than leaves. So it doesn't grow very fast, but I don't mind.
I think P. baronii/windsori is supposed to be another tricky one. I have avoided it for that reason (and the price). Both densiflorum and eburneum have done well here. They're not fast but they do keep on chugging. For whatever reason my densiflorum has a short growing season (late summer) but maybe that will change over time.
Back to the watering question. Another thing to bear in mind when you fine-tune the watering schedule is that it's not black and white, all or none. These are opportunistic plants, and they respond to attention, but you need to watch them to see how they're doing and when they're receptive. The Pachys around here are never all in leaf at the same time.
Typically right before Pachypodium leaves fall, they change shape and change color to brown, yellow, or purple. Or they develop spots. That can be a signal to start reducing the water. But don't pre-empt the plant, unless you want to trigger hard dormancy on purpose. Likewise, when you first see buds, don't turn the tap on all the way at once.
As you can see, there is quite a bit of plant psychology involved in this. But I have yet to lose a Pachypodium, so it seems to work. Other genera have not fared nearly so well here. Maybe because I find it harder to tell what they're thinking. Ha.
Naw. It could be the climate. It's real mild here. And there are few real temperature swings except for the warm, dry Santa Ana events in winter (which I guess you have too to some degree). Most of my Pachys were leafing out by early February.
Do you fertilize every time you water, or are you watering without fert after repotting and when plants are dormant? That's the only other thing I can think of which might matter. I have been waiting to fertilize until after plants are established in a container. Acidification did seem to be helpful, best I could tell. All my Pachys get sun for half a day or more. Most of them get water once a week this time of year, a few get an extra spritz after 3-4 days for good measure.
I have recently started fertilizing many times I water (though not every single time, especially when I ask friends to spray down the patio when I'm out of town). I definitely didn't try transplanting or watering with fertilizer while dormant. They get full-to-filtered sun, usually from being next to taller plants. A couple I keep under 50% shade approx. We'll see how it goes. I kill adeniums, too, but I have quite a few still plugging along currently.
Yeah, P. bicolor and P. eburneum are definitely a challenge for me. *sigh* Really, most of the small Madagascar types.
Of those that look somewhat similar, I've had better luck with P. horombense, but I kill those with some regularity, too. Several are still chugging along in my yard. I kept P. cactipes alive for a while (from the Huntington), but I killed their P. makayense rapidly (and it was heartbreakingly $$$ for its size). Being a glutton for disappointment, I just bought a small P. makayense from Out of Africa (it was only $ this time; I'm learning). I have a P. rosulatum from Grigsby which hasn't grown much, but it hasn't died either.
I killed P. drakei, but it took me a while ("killing me softly…with his song"). A large-ish P. 'Mandritsara Form' bought at the same time is still kicking along. It never seems to go completely dormant. In fact, I could swear I have killed MORE pachypodiums by accidentally drying them out than by watering too regularly. They seem to cross some crucial threshold of dryness, shrivel a bit…then I water and they rot quickly and catastrophically. It seems that once the roots are slightly dried, they are sitting ducks (under my conditions). I don't think I have ever managed to revive a slightly shriveled pachypodium…not once! On the other hand, I have often watered them during the "off" season when they have leaves, usually with no problem.
The other issue for me seems to be that if the plant is injured or otherwise compromised, its decline is rapid, unforgiving, and certain…unlike so many of our cacti & succulents where we can take cuttings or re-root the body of the plant.
I have to wonder if these are really best thought of as greenhouse plants. I'm still growing without a greenhouse.
I don't think the greenhouse is necessary, at least it isn't here. I do give my plants some protection (from rain when leafless, from sun for part or most of the day). That can be accomplished by moving them around to take advantage of shade and overhangs.
Little ones are going to need more protection, of course. Regular window glass is pretty good for that purpose. But all my Pachys get some daily sun, and I water them at a pretty set interval, which is about once a week when they're in leaf. Don't know how much that matters, just sharing my experience in case it's helpful. My plants do not ever dry out all the way when they're in leaf, or at least that's my goal.
Some species enjoy our winter rain with no protection (lamerei, geayi, bispinosum, namaquanum), but I have kept the other ones under an overhang... unless the rain comes on roughly the right day, in which case even leafless ones come out to drink up. I love the watering holiday, it's one of the best perks of winter.
One day we will install shade cloth over part of the patio, and that will make the space more habitable for more plants. But for now there's almost no filtered light available around here. So I have made a real effort to find plants that can take some sun, and Pachys have performed like champs in that respect.
If you're really hard core about figuring these plants out, I highly recommend the pictures and text that come in the two Pachyforms books (a total of 10 Pachypodiums discussed by name). There are 7 species in the first volume (the more interesting ones in my opinion), plus 3 in the second. The cultivation notes were useful to me. Pachyforms is a better resource for fat plants (in my opinion) and more up-to-date than Rowley's Caudiciforms book, but both have a lot to offer.
Ah, nice reference pointer to Pachyforms book. I didn't know it. I will look out for it.
I have followed quite a few of the culture tips available from growers online, gleaning information from Out Of Africa Plants, Highland Succulents, and trying to apply some similar culture as I've picked up from Mark Dimmitt's pages on adeniums (a fairly close Apocynaceae relative to pachypodiums), Arid Lands, Bihrmann's, Plantzafrica…but a lot of these are short on culture tips.
I have a lot of local resources in my fellow club members at San Gabriel Valley CSS. But a lot of the real experts have greenhouses, so it's a slightly different situation. Still, since it's a problem and I've asked about other plants; I should find the right moment to ask about Madagascar pachypodiums.
I do have some areas set up with shade cloth or natural filtered light. You're absolutely right; these do seem best for my pachypodiums. My Pachypodium horombense doesn't seem to mind the winter rain here. But winter rain might have hastened the downfall of P eberneum, bicolor, cactipes, baronii windsorii, baronii, and rosulatum drakei. (A long list, and I'm probably forgetting even more plants I've killed :-).
I don't have much trouble with the S Africa types—P saundersii, bispinosum, succulentum, griquense—or the tree types—P lamerei, mikea, geayi. I'm doing okay with P namaquanum, though I've killed 1 or 2. It's the small Madagascar forms which give me the most trouble. Every winter my larger P rosulatum Mandritsara form and P baronii survive, I feel like I've dodged a bullet.