In this guide we will try to shed some light on how we grow our Adeniums and Pachypodiums from seeds. We have grown various adenium species (from Adenium obesum to Adenium oleifolium) as well as a fairly wide range of Pachypodium species for the past 3-4 years.
Understanding their natural habitat
Adeniums are usually distributed across the african continent and the arabian peninsula and they are classified as caudiciform plants (in simple terms plants that have specialized adaptations for storing water whenever possible as they live in areas where water is usually very scarce).
The Pachypodiums however have a much more restricted native area, and they can be split into two major groups: the madagascar pachypodiums (20 species) and the south african pachypodiums (5 species). Most pachypodium species are endemic to their regions and some are endemic to a highly restricted native area (Pachypodium ambongense).
Just as adeniums, pachypodiums are classified as caudiciforms as they are also natively present in areas with very limited water supply.
Buying the seeds
Buying the seeds is a somewhat tricky process, as the seeds of both adenium and pachypodium become unviable after a period of roughly one year. Usually the seeds need to be as fresh as possible. There are some materials claiming that very fresh seeds will also not yield a very good germination rate but we didn't have the chance to put this to test.
As the rule of thumb, the seeds usually appear on specialized websites as soon as they are available so they will be fresh. One thing to look out for is that some of the seeds are highly sought after, and they will be sold very fast, while other seeds will probably be overstocked, and they might not have a great germination rate as they sell slower. Usually we monitor a few websites that are specialized in succulents. Some of them are listed below:
- baobabs.com / Le Jardin Naturel. They are specialized in caudiciforms, with a strong pachypodium presence. Other member of the Apocynaceae family are sold on the website (plumeria, adenium). The seeds are usually very fresh with germination between 70-90%. Shipping is worldwide. For rarer species it can get somewhat expensive.
- rarepalmseeds.com - A Munich based website that deals with importing a wide range of seeds but not specialized in caudiciforms (adeniums, pachypodiums, dorstenia, cyphostemma can all be found there along other seeds like haworthia for example). Usually the germination rate is good, but sometimes it can happen that the seeds are a little bit old and the germination rate drops to 40%. They usually have very decent prices.
- Koehres Kakteen - A Germany based shop that has a wide range of succulent seeds available, among them pachypodiums and adeniums. There have been some reports of low germination rate in some cases, but for me personally it always worked out pretty good, in most cases germination being between 70-90%. Rarer seeds will sell fast.
A side note, it is usually beneficial to know when the seeds of various species are available. For example the seeds of Pachypodium ambongense are usually available between december and february.
Preparing the seeds
Usually we soak the seeds for up to 24 hours in warm water (room temperature). Some guides recommend disinfecting the seeds (some species of pachypodium can come infested with a fungus which will render them unviable), but we personally never disinfected any seeds, but depending on source this should be considered.
Preparing the soil
Both pachypodiums and adeniums really hate waterlogged conditions. So the soil needs to be very porous. However, for the germination, a higher humidity than usual is needed, otherwise the germination will not take place.
Recently, we are preparing our own soil for planting, usually with a distribution of 90% inorganic and 10% organic. Do not use small grained sand as that tends to hold water wayy too much and will lead to the seeds rotting.
As an example, we have recently received twenty Pachypodium ambongense seeds, out of which sixteen germinated. The soil composition that we have used for germination is as follows: 2 parts travertin (a type of limestone), 1 part large grain sand (2-5mm grains), 2 parts pumice (2-5mm grains), 1 part zeolite (2-5mm grain) and 1 part regular quality cactus potting soil. This is a composition that will allow us to keep the pachypodiums longer in their original container (thus allowing a better root system to be developed before being moved). The soil has very good drainage, while being able to hold water for some limited amount of time without becoming waterlogged.
Beware, the above mentioned example will generally only work for Pachypodiyum ambongense as it is one of the species that prefers a not-so-acidic-slightly-alkaline soil. Travertin is a type of limestone, and zeolite contains a fair amount of calcium. This should not be used for species that prefer medium/highly acidic soil (for example pachypodium brevicaule).
Watering, light and heat
The watering is usually the tricky part when it comes to pachypodium and adenium species. What we like to do is plant the seeds in trays with lids. We usually keep the plants very well ventilated for sixteen hours a day, and the lid close to create humid atmosphere for eight hours a day.
Regarding the light, before germinating, the seeds require no light. After germination it does help to have a strong set of grow lights above the plants so they can enter the growth cycle.
Regarding heat, we always use a heatmat and we keep the ambient temperature roughly around 21 or 22 degrees celsius. Bottom heat is extremely important, as without it the seeds will be unlikely to germinate.
Positioning the seeds in the soil
Another very important thing is how to position the seeds in the soil for germination. Depending on the seed size, we plant our seeds somewhere between 1.5 cm to 0.5 cm depth. This is very important from our experience, as seeds planted too deep might rot and seeds planted too shallow will have big issues with the protective seedcap. The role of the soil is to create friction on the seedcap so that the seedcap comes of easily.
However, even if the seeds are planted too shallow, the following trick works in almost all cases:
- usually the seedcap will be dried out because of lower humidity
- spray 2-5 times the seedcap with a little bit of water at 5-10 minutes interval. This will usually weaken the seedcap.
- with the help of a tweezer, gently try to remove the seedcap or to split it open. Usually there will be a crack in it where the seed root system starts developing. If the seedcap is still too stiff, repeat the previous step.
- be very very careful as you can kill the seedling this way and this will be fatal for the seedling.
The ventilation is a critical component if you want to have strong and properly grown plants. We use a normal apartment fan set to the lowest speed in order to move the air around. This leads to the soil drying faster as well as the humidity being dispersed and allowing the seedlings to grow stronger.
The usual germination time is as low as three days (for fresh seeds) up to two weeks (depending on species, germination conditions, seed freshness).
If planted in a container with a lid, do not keep the lid on at any time after germination as it might lead to seedling rot.
When to repot
Usually most tutorials will recommend repotting when the second set of true leaves appears. We prefer to grow our seeds in containers for at least a few months though, and the containers that we use are roughly 5-6 cm tall (so fairly shallow). The soil is prepared individually for each plant. In this way, the root system is usually better developed when we decide to repot.
Do not use containers that are too deep, as they tend to accumulate water at the bottom, potentially inviting root rot.
We hope we covered most of the process of growing Pachypodiums and Adeniums from seed. Please take this information with a grain of salt as this is only from our experience, and we consider ourselves still beginners.
Some of our seedlings
Below are pictured some of our seedlings from 2020 and 2021. Images taken Jan. 30th, 2021.
Our grow tent. Left: various Adenium species, right bottom Pachypodium bicolor, right top Pachypodium ambongense
Pachypodiums: bottom Pachypodium bicolor (~1 week old), top Pachypodium ambongense (~2-3 weeks old)
15 Pachypodium ambongense, (2-3 weeks old).