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Covering soil of indoor plants with rocks or gravel? OK or not OK?

L Evve (Miami)
6 years ago

Hello - I was wondering if covering all the soil around a succulent or aloe vera plant with rocks is good or bad for the plant itself? I dont know if the soil should be in more direct contact with air and light? Or if it irrelevant? --- Rocks look better than black soil/dirt, but I want to know if this will affect the plant or not.... Example of what I am saying below pics...

Comments (12)

  • SpanishFly - (Mediterranean)
    6 years ago

    I also use a coarse gritty mix and a top dressing, often marble chips. It looks nicer than just plain soil, and gives shelter to any seedlings that sprout from seeds that fall off the plant.

    L Evve (Miami) thanked SpanishFly - (Mediterranean)
  • L Evve (Miami)
    Original Author
    6 years ago

    Thank you!! I am in the Boston area.

    I use "Miracle Gro, Cactus, Palm & Citrus Potting Mix"' and my pots are glazed/painted (so the pot itself is not absorbing any water as the terracotta ones do), however, they have holes on the bottom and I also used the IKEA ODLA growing media (clay pellets) at the bottom of each pot... However, after watering them, it doesn't seem to dry out immediately or fast, it stays kind of moist mainly...

  • rina_Ontario,Canada 5a
    6 years ago

    I do not know IKEA pellets, maybe you can post photo? They could be used as a media to grow plants in, but anything layered at the bottom of pots to improve drainage actually doesn't. PPL that use soil you mentioned mix it with coarse/sifted-screened perlite, in min. 1:1 ratio. You could use more perlite. All ingredients should be mixed thoroughly. Layering could cause more problems, regardless what you may have read - there are many "how-to..." ideas on net that are quite inappropriate for succulents.

    If your mix stays moist for too long, there is likely problem with it. Glazed pots could be used, but free draining potting mix would be even more important.

    I can't tell what are plants in 2nd photo. But if they are mesembs as 1st seems to be, they may rot very fast. They have very particular watering needs.

    L Evve (Miami) thanked rina_Ontario,Canada 5a
  • L Evve (Miami)
    Original Author
    6 years ago
    last modified: 6 years ago

    The pics are not my plants, I just used the form the internet to illustrate the matter.

    Pellets pic below...  ... I thought the Cactus Miracle Gro mix was the perfect type and designed for this specifically...

  • rina_Ontario,Canada 5a
    6 years ago
    last modified: 6 years ago

    They look like Hydroton (another name used is Leca I believe); and as you can see, they are of quite different size. They could be too large for the mix, but OK for top dressing and are used for growing plants hydroponically.

    I don't use soil in mix for succulents, but many ppl that use same as you mentioned that it may not be draining as well as advertised. That is why they mix it with perlite. That mix seems to work well. You could use even more perlite than half of total volume. Here is photo borrowed from one of our members, Crenda, showing soil+perlite mix she uses:

  • Karen S. (7b, NYC)
    6 years ago
    last modified: 6 years ago

    Hi L Evve,

    I'm not a user of top dressing. As said above, some do, some don't. But if one did, I'd suggest rocks in 1st pic are too big/ too heavy & I'd expect they'd damage the leaves somewhat (I do see that's a heavyish plant needing support while settling in), but in my opinion it's planted too deeply along w/ covered by too big/ too heavy rocks.

    The 2nd pic looks fine & seems more like what folks like Rina do.

    I grow more like Crenda, w/ Cactus & Succulent mix along w/ Pumice (equal parts each). One can do this w/ Perlite or Pumice interchangeably; either will improve drainage.

    Even Miracle Grow Cactus mix needs added Perlite or Pumice. You'd think it wouldn't but it does. Read around here long enough & you'll see most of us have learned that the hard way.

    Sorry to say your clay balls are the problem here, especially when used w/ Succulents. Those clay balls are porous & can drain fast but can also HOLD water for a while. I use those Leca stones as growing medium for my Hydro plants, a Hoya & a Sans. That's all they grow in, those stones & water.

    This is especially bad for succulents, Aloe included, as you want everything fast draining, including their roots. In your case, it'll drain down to the Leca stones where the moisture will stay in the Leca stones for some time, ultimately resulting in root rot since the roots won't dry out enough to take up oxygen.

    Whatever else you do or don't about the soil, pls. get the clay balls out of there or I suspect you'll lose your plants.

    Didn't intend for such a long response, but there was a lot to explain.

    My Sans. (abt 7 yrs. old).

    Those clay balls are Leca stones, specifically sold for Hydro growing. I hear Orchid growers may use them too.

  • Jeff (5b)
    6 years ago
    last modified: 6 years ago

    " I thought the Cactus Miracle Gro mix was the perfect type and designed for this specifically..."

    I used to think that too. At the risk of sounding like a fanatic: Miracle Grow cactus soil is basically potting soil consisting of mainly peat moss (as opposed to plain peat or peat humus, which is even worse), and a tiny bit of perlite, with some added sand. Sand will make it heavier and gloppier (sorry for the technical terms). The particles are too small for them to really make it faster draining, plus it does hold some water. It has been said that larger ingredients (like perlite, pumice, etc.) need to make up at least half of the mix if there's peat moss, in order for them to effectively increase drainage and especially porosity (giving roots more air). But what I find interesting is that even African Violet growers recommend 1/2 perlite and 1/2 potting soil. Many people who grow succulents use that, but watering needs to be done very carefully, as in not too much. I don't really know how Miracle Grow, Schultz, Scotts (all of which I've used), and the others can market that as cactus and succulent soil. That's not a reflection on L Evve, I'm just saying. I've gone through all of that.

    I've stopped using peat moss at all for all cactus and most succulents, but if I was using a peat moss based soil with ceramic pots and also top dressing, and all I had was perlite and 'potting soil', I would use at least 60-70% perlite. Then you need to water over the sink or into a pan or whatever, because a dish below the pot won't be able to hold what a thorough watering would release out of the bottom.

    Again, I realize we might sound like fanatics, but I can assure you everybody who grows these plants is like us, not necessarily the no-peat-moss part, but the importance of a free draining mix.

    Here is an example of a peat moss and sand based mix in a plastic pot with pebbles as top dressing:

    I did drastically prune the top branches but the bottom part is rotted with no roots left. (In another thread I said I wasn't going to describe all that I did wrong, but I'll sacrifice one for the team.) I really didn't think I was watering it too much. I found this out recently as I'm gradually repotting almost everything. So I'm learning too.

    Sorry for the long off-topic post. I thought this might be beneficial.

  • robinswfl
    6 years ago

    I think the use of top dressing varies from one gardener to another. In the beginning, I never used it. But over the years, I have started. Mostly I use the kind of "polished" small stones shown in the first photo, or washed and moderately attractive pea gravel. I have a large number of plants in a mix that is about 40% sifted c/s soil, 30% pumice and 30% manna pro poultry grit. I don't often top dress plants that have a real c/s soil mix as a base because, honestly, sometimes I want to stick my fingers in and really test the dampness.

    But for plants in an grittier mix (mine is 2:2:1 pumice, manna pro and Turface -- not being a big fan of Turface), I often do top dress. Most of these are small succulents in terra cotta pots, and I think top dressing helps hold the moisture in a bit better.

  • Janice May Limbaga
    3 years ago

    Hi can I ask what's best soil tu use and some mixtures to put an d percentage of each? What rocks to put on top? I have some friend who advised me to mix vermicast and rice hull, while some ask me to put carbonized hull, sand, vermicast.. I'm confused. Please help me. Thanks

  • Anubhav Kapoor
    2 years ago

    I have just started dressing up a lot of my plants. It is hot here, but I don't see this affecting the health of the plants as such. I tend to use small gravel, colored pebbles, and small polished pebbles. The big disadvantage is that when it is rainy and when the planters are located in tight spots, the soil dressing does not allow you to get an idea if the soil has become too dry. If you know the watering schedule of your plants really well, this should not be a problem. In fact, I have just placed an order for a few pounds of onyx-colored stones in the bright yellow shade, and I am sure they will look gorgeous. Will also share some pics of the same - promise!

  • Daniel Rene
    2 years ago
    last modified: 2 years ago

    Couple of things I’d like to add to this thread with regards to why top dressing is a good thing;

    1. It keeps pests like fungus gnats from being able to find the moist dirt and lay their eggs

    2. In nature, dirt is almost always covered - and i feel like mimicking nature is not a terrible idea.

    Just my 2¢