Sphagnum moss at bottom of pot for seedlings?
Posted: Sat May 22, 2021 3:29 pm
First of all I am not sure if this topic fits better into the "Cultivation" or the "Grown from seed" section, please let me know if this is the wrong forum for this question. I have searched the forum with the keywords "sphagnum" and "bottom" but didn't find anything directly about this method (described below). However, mixing sphagnum moss into the seeding soil seems to be more common, and maybe it has the same effect.
Now to the story:
I have managed to obtain a relatively cheap copy of the book "The Encyclopedia of Cacti" by Cullmann, Götz and Gröner from 1986, and I have already learnt A LOT I didn't know before (despite spending hours on different forums) from reading through all the introductory chapters about cactus biology, care, and propagation.
I am currently on the propagation from seed chapter, and was surprised to see them recommend using a layer of sphagnum moss at the bottom of pots for seedlings (see attached photo), both in the sowing stage and the first times they are pricked out. The reason they give for this (as far as I understand) is twofold, 1) to keep the soil moisture at a more even level, and 2) to buffer the pH to stay at a consistently low level, the reasoning here being that bottom watering otherwise leads to salt deposits in the upper layers of the soil, which will increase the pH to alkaline levels and thus stall the growth, and the sphagnum peat in the bottom will prevent this effect to a certain degree due to its low pH value. Now I was wondering if anyone maybe has tried this? Intuitively it doesn't seem like a good idea to put such a moisture retaining material at the bottom of the pots?
Now to the story:
I have managed to obtain a relatively cheap copy of the book "The Encyclopedia of Cacti" by Cullmann, Götz and Gröner from 1986, and I have already learnt A LOT I didn't know before (despite spending hours on different forums) from reading through all the introductory chapters about cactus biology, care, and propagation.
I am currently on the propagation from seed chapter, and was surprised to see them recommend using a layer of sphagnum moss at the bottom of pots for seedlings (see attached photo), both in the sowing stage and the first times they are pricked out. The reason they give for this (as far as I understand) is twofold, 1) to keep the soil moisture at a more even level, and 2) to buffer the pH to stay at a consistently low level, the reasoning here being that bottom watering otherwise leads to salt deposits in the upper layers of the soil, which will increase the pH to alkaline levels and thus stall the growth, and the sphagnum peat in the bottom will prevent this effect to a certain degree due to its low pH value. Now I was wondering if anyone maybe has tried this? Intuitively it doesn't seem like a good idea to put such a moisture retaining material at the bottom of the pots?