Black Lava Rock

[tjwalters]

I just bought some black lava rock - the kind that can be used in a gas grill - to cover the soil of a potted Adonidia merrillii (about 5' of bare trunk) so the cats can't dig/eat it (the soil).  I'm assuming it's ordinary lava rock and will be harmless to the cats and palm.  Thoughts?  Sure looks nice.

[Mr. Coconut Palm]

Where did you get it from?  I am considering using as much as I can afford when I plant my coconut palms in my yard in a couple of months to absorb heat during the day so that in the winter, the soil temp will be a little higher, plus plants seem to love it in Hawaii, where they grow like they are on steroids.

[tjwalters]

7 minutes ago, Mr. Coconut Palm said:

Where did you get it from?  I am considering using as much as I can afford when I plant my coconut palms in my yard in a couple of months to absorb heat during the day so that in the winter, the soil temp will be a little higher, plus plants seem to love it in Hawaii, where they grow like they are on steroids.

One of the local big box hardware stores.  The bag mentioned something about it being great for use in grills, but it didn't seem to be limited to that purpose.

Also came in red.

[Mr. Coconut Palm]

Okay, thank you.  We have it here too( the bags of lava rock) at the big box stores.  I didn't get much sleep last night and I thought your post was about lava sand, which is what I am actually looking for, black lava sand.

[_Keith]

18 minutes ago, Mr. Coconut Palm said:

Okay, thank you.  We have it here too( the bags of lava rock) at the big box stores.  I didn't get much sleep last night and I thought your post was about lava sand, which is what I am actually looking for, black lava sand.

Got a sledge hammer 

[Mr. Coconut Palm]

Hey Keith,

I have actually thought of breaking up bags of the rock.  It would probably be fairly easy to do while it is still in the bag.  There is actually a local nursery that has some small bags of lava sand, but as I recall, they are pretty expensive, something like $7 or $8 for a bag that is only a few pounds.  I think I would be spending well over a $100 for the amount I would need when I plant 5 to 7 coconut palms in my yard in the next couple of months.  I need to find out from someone who has been doing organic landscaping longer than I have if adding enough 100% organic compost to my very sandy soil will actually increase my winter time soil temps by about 3F or 4F.  I read somewhere a while back that a healthy rich organic soil has higher temps due to all the microbial activity going on, and large compost piles sometimes catch on fire due to the extreme heat of the compost breaking down.

[redbeard917]

10 hours ago, Mr. Coconut Palm said:

Hey Keith,

I have actually thought of breaking up bags of the rock.  It would probably be fairly easy to do while it is still in the bag.  There is actually a local nursery that has some small bags of lava sand, but as I recall, they are pretty expensive, something like $7 or $8 for a bag that is only a few pounds.  I think I would be spending well over a $100 for the amount I would need when I plant 5 to 7 coconut palms in my yard in the next couple of months.  I need to find out from someone who has been doing organic landscaping longer than I have if adding enough 100% organic compost to my very sandy soil will actually increase my winter time soil temps by about 3F or 4F.  I read somewhere a while back that a healthy rich organic soil has higher temps due to all the microbial activity going on, and large compost piles sometimes catch on fire due to the extreme heat of the compost breaking down.

Compost does indeed release heat as it's broken down, but I think it would have to be a pretty thick layer to make a substantive difference to your palms. At the dump I get composted yard waste, which can be so hot it's steaming. But I just spread a wheelbarrow-sized load in my mother's garden and it was cool to the touch. It was a 50deg F day and the pile had been saturated by rain. A layer of just a few inches would impart a negligible amount of heat, IMO. Plus the microbial activity might be slowed on a cool day so less would be generated. In the first place. The compost might, however, have an insulating effect on the sun's heat. Or, if you put a large enough pile by the palms (I haven't seen one smaller than about 4 feet high steaming), but that might be unsightly.

[Mr. Coconut Palm]

You are probably right, but since my yard is about 98% sand, and a light colored sand at that, that is actually almost an off white color when it is dry, I was hoping to get just a few degrees of increase in soil temp.  I would be happy with just 3F increase, which should put my soil temp right at the minimum 60F winter time temp for coconut palms.