Cactus Mulch/pebbles/aggregate

[Gollum]

Just wondering what other people are using around the base of their cacti? I have gone through many phases. First off, when I started out I didn't use any top dressing, just bare cactus mix. Then I used decorative pebbles, white mainly, then when I grew tired of the sterile, un natural look, I switched to more earth toned pebbles.

After a while I wanted something different and more benificial to the growth of the cacti. So after doing a bit of research I went in search of limestone screenings (apparently the natural habitat of the cactus I choose to grow is rich in limestone). I had all sorts of trouble finding limestone where I live as it mostly shale and blue rock that they quarry here.

After lots of phonecalls and driving around, I found it at a landscape yard labled as 'white rocks'. They were a bit too big for what I wanted to use them for, 2cm x 4cm, so I sat out in my backyard with a paver, goggles and a hammer and proceeded to smash they down to the size I wanted. Yes I got some funny looks from my house mates.

Anyway, after dressing the limestone around the base of my potted cacti I was initially happy with the end result.

Fast forward a few months and after some decent growth. What I didn't realize at the time was that my small limestone chippings had quite sharpe and pointy edges. So as the cacti grew they pressed the limestone between the soft flesh of the cacti and the edge of the pot, sometimes digging into the plant and disfiguring it.

So I am at the stage once more where I need to find another type of mulch/rock, obviously with smooth edges to use.

I would love to hear what others are using and to share their experience with dressing around their plants.

Cheers.

[J Smith]

I use pea stone in earth colours. $7.50 for a 25kg bag.

[zelly]

after similar trials & errors I've concluded top dressings are more of a curse than a blessing. the biggest drawback is trying to determine a plants watering needs for soil you cannot see or access. top dressings generally dont allow the soil to breathe & they offer excellent hiding spots for unwelcome insects & other critters

if you do decide to go with a top dressing, i've found the best to be 2-4 cm black polished or smooth rock. black absorbs the suns heat and holds it better than other colors and the added warmth seems to really help in overall growth.

[Optimystic]

I use expanded shale and I just get the hang of when I need to water... originally i did it to keep perlite from flying away, but the point for me is its very hot here during the summer and I don't want to water every day or two... in plastic pots I can get away with weekly watering or less often for most plants. im sure that will change as they get huge... it still lasts pretty long in clay pots several days before the top is dried ... the ones that aren't mulched dry out a couple inches deep withing a day or two when its super hot... certainly you don't want to mulch until the roots are well established.. in my hot climate plants are growing better this year with a combination of that and richer soils... fact is I don't always remember to water so i've been doing alot more deep watering on the plants , especially the few that aren't mulched.. I didn't mulch some cause Im planning to repot but everythign got away from me this year due to anxiety and shit

I like the shale because its good at holding moisture... great for triches but maybe not so much for other species

on the other hand I had a pot mulched with granite stones last year and had a huge PC pach in it... over the winter it was the last PC to rot, but all my outdoor pc's rotted, huge or not... when I removed the biggest plant I discovered that the soil was still wet and im not sure if it leaked/dripped in there or if the pot was just wet all winter lol ...either way if you have a heavy dressing its probably a good idea to check under it during the winter, if you get winter... Shale is ez to check under just like soil almost.. the top will dry but if you make a reasonably thick layer it will maintain wetness just below the surface .. i suppose thats what mulching is for or something like that lol

Mulching in the ground I would think is an entirely different set of dynamics

Edited September 15, 2014 by Spine Collector

[franky]

I use 14mm scoria

[waterboy 2.0]

7mm bluestone (dolerite)....use it heaps for work and its everywhere cheap here, as the predominant geology.

[Gollum]

Some good suggestions there. A while back I used expanded clay balls, they were tiny, about 5mm in diameter. Im thinking of switching back to them but cant seem to find them. Has anyone else seen them it their travels?

[Gunter]

I ended up using compost twice annually to topdress.

[zelly]

A while back I used expanded clay balls, they were tiny, about 5mm in diameter. Im thinking of switching back to them but cant seem to find them. Has anyone else seen them it their travels?

you might look into turface, some people swear by it

[Glass Roots]

Turface is amazing for Bonsai!

[Optimystic]

yeah also there is a turface like product in the states called Napa Oil Dry... I never found turface but that was ez to find.. not sure if you have napa auto stores but its a product used to soak up oil spills in garages... I think there are different grades so maybe be careful about and read up on the qualities before getting any old oil spill cleaning stuff..

seems like it would work good, especially here since there is enough heat that I'd rather have somethign that repels a little of it .. I use it for sansy's I made "Al's gritty mix" with a little compromise using that and my exotic sansy's are doing well in it even though I think the conifer bark chips maybe have been a little on the large size

Edited September 19, 2014 by Spine Collector