I've been thinking of lava rock as being equivalent to granite grit. Upon further reflection, this isn't exactly true. Granite grit is relatively smooth compared to lava rock. A piece of bark, coming in contact with a piece of granite grit, could have have an extended contact surface that is relatively tight. The contact surface may have micro spaces about 1/100 to 1/10 of a millimeter, or about 10 to 100 times the size of a bacterium, or just at the size limit of human vision. Lava rock is rougher. An extended contact surface with a piece of bark could have mini spaces in a size range of 1/10 to 1 millimeter; ie., barely above (to fully within) the limit of human vision. Turface is about as smooth as granite; so micropores in an extended contact zone between bark would be about the same size as with granite. But since granite grit sometimes has angular ridges while turface is globular, any extended contact zones between bark and turface could be larger than extended contact zones between bark and granite. An extended contact zone could mean that the internal water reservoir of a turface granule (at the pseudo-dry but glossy stage) would flow into the bark (and vice versa). While I don't believe that lava rock has an internal water reservoir per se, an extended contact zone above a tide pool (a pit on the upper surface of a lava rock) would as a mini reservoir, while an extended contact zone below a pit (on the underside of a lava rock) could act as an oxygen reservoir. ------- disclaimer -------- I have observed none of this under a microscope, nor read any soil text relating to this. I am just using logic based on my memory of my naked eye observations of turface, lava rock, chicken grit and bark. ------ punch line ------- If my logic is correct, how does all of this effect drainage, the medium and long term storage of water and oxygen after drainage, and the wicking of water and oxygen reservoirs to roots in the medium to long time frames? I have no real idea, but it is fun to think about. I speculate that the mini (1/10 to 1 millimeter) water and oxygen reservoirs in the contact zone between bark and lava rock wins in the short to medium term (about 1 day after drainage). I speculate that the micro (1/100 to 1/10 millimeter) reservoirs in the contact zone between bark and turface wins in the long term (a few days after drainage). In the system bark and granite grit, grit is just a spacer that creates macro pores (about 1-2 mm) of oxygen, not having any real function as a water reservoir.

Hi, If you check Craigslist and other classifieds, and tell everyone you know that you're looking for bricks (or anything else) they may start showing up on your porch. I put out the word that I need bricks and in one month, there are over 1500 of them in my yard, all for my favorite price, FREE!! A friend of mine says that there are a few bricks everywhere. It appears to be true. If you get bricks from lots of sources and mix them up, they just all go together. Sand is cheap to lay them on. If you dig down in the soil to make the bricks level with it, you won't need rebarb around the edge to hold them in place. Some people on the Garden Junk and Trash to Treasure forums have made paved areas out of wood and other materials. You may want to post this question on those forums. There's a lot of wood being thrown away everywhere in the form of pallets and old redwood or cedar fence boards. You can build a frame from 2x4's or pallet 'stringers' and nail the fence boards on top of them to make a wood floor. If the termites move in, just throw it away and make a new one. (Treated 2x4's are inexpensive and shouldn't be attacked by termites.) Total cost-the price of nails or screws. If splinters are an issue, the boards can be sanded and finished with any exterior stain, sealer or paint. Anyone with 7th grade carpenter skills could help build this thing. You may be able to find a sale on new fence boards and be within your landlord's budget. The wood is far less work than bricks and will possibly be cooler to walk on. This answer has nothing to do with landscape design, just a few ideas about getting a cheap patio. Hope that helps, Linda

I can't get rid of our lava rock, unfortunately, but I'm wondering if anyone can help me figure out how to deal with the weeds? My husband and I just moved into a rental home with a lava rock yard in front. Not our favorite landscaping choice, but the rest of the house is nice. Landlords are not open to letting us change it, and after the first rains of the season (N. California -- East Bay) a billion weeds sprung up. I have spent a couple sessions trying to pull them by hand, but it is really impossible to get them up through those rocks (and there is some sort of black plastic tarp underneath, that is not in good shape). Can anyone offer suggestions? I am almost 7 months pregnant, so I can't really get down there to do too much more hand weeding right now, and I'd rather not use anything horribly toxic. Landlords expect us to keep up the landscaping appearance, so we need to do something soon. Thank you!!

You may want to try the landscape design forum, since your question is more general than just stone. They will probably have good ideas, and it's a more active forum than this one.