Semps & some sedums will grow in minimal soil, but it may be best to have some well draining substrate below rocks. Planting into it and letting plants to spread is the best way. What is the soil like and how thick/deep is the layer of rocks? If you have poor drainage below rocks, it could cause problems eventually. Rocks do not have to be large, any size works, from grit to boulders.

Rina - You've been so helpful!

The soil is just my yard, and it's gross. It's heavy clay, and although the grass does seem to grow pretty well, it does puddle for a short time after a heavy rain. We haven't really determined how thick the layer of rock will be - it's just a border so not very deep, maybe 4"? We're honestly flying by the seat of our pants and DIY'ing it, so I'm open to any suggestions or tips I can get :)

You may need more soil than you think, once you water it will begin to settle downward into all the nooks and crannies in your rock pile and you'll need to top it up - In my experience hehe

I've crammed Spruce cones, gravel. and other debris in as filler with the soil as I'm building up (I have two huge spruces, the cones are omnipresent).

kd

Kd

Don't you worry about many spruce seedlings growing in your rockery :)?

Pluto

If the soil is very poor draining clay, make sure you don't create a "bathtub" - if possible, some sloping of soil under the rocks may help drainage. Then topping it with rocks - top could be leveled if that's what you want it to look - and planting where the soil below is the highest may work. (Not sure if I am explaining it right...)

Rina - I think I do understand what you mean - basically dig the back a little deeper than the front so the dirt actually slopes towards the deck skirting (or away, whichever we decide)) then put the rocks so they're flat and level (which means deeper in part), then plant in the shallow side and let them spread towards the deep....

It wasn't our intention to really dig out much if anything - other than the sod to expose bare dirt - then lay the rocks on top of it, so it shouldn't really create a bathtub effect if we're not really digging into the soil should it?

Bunkfree - I honestly hadn't thought about it compacting/washing away - you're right, I will need more than I think! Thanks for that tip.

Pluto

I do not know what is your set up, but I think I would prefer sloping away from the deck - toward rest of the garden. And the slope doesn't have to be huge, for a good runoff, about 1.5"/2-3' should be enough. You don't need to dig, at least not much - you would be raking the ground before putting a gravel/rocks on top, won't you? After you take off the sod, ground should be raked, so just rake it higher closer to deck...And plant semps and sedums where the soil is higher, not lower (water will drain from high to low...so better chance of dryer substrate where the planting is).

JMO - that is what I would do. I'll get some pics of semps growing over rocks later today (rocks are bigger than what you are thinking, but same principle - so you can see there is no soil piled up. But original plant was planted in little soil by the rock, or in-between.)

Rina - Thank You so much!

I've found a few of the Sempervivum Oddity like you showed in another post, I just haven't decided which of the sellers seems best (ie, not likely to ship a half dead plant across the US by the slowest method). I also found some via Etsy for a place that has a greenhouse close to me. They don't have the plants listed at the greenhouse website, so I've reached out to them to see if they have them in stock or not - I'd rather not pay for shipping and be able to choose the plant myself if I can just drive 1/2 an hour.

I did go to a closer greenhouse last night and pick up a few Semps - they only carried the Chick Charms branded ones, but I got a couple different kinds.

I saw the title and I thought you were making a lithops garden...

succulentss - :) - Nope, I'm not ready for lithops. I don't have the patience to wait a year to see a change in a plant...

haha. well, I think it would look super awesome! I can't wait to see how this project turns out, good luck. pls post pictures when you finish it:)

I would also like to see pics - don't forget the "before" ones!

Rina - I'm past worrying about spruce seedlings haha.... pulling them out is part of my regular weeding process :D I have many healthy specimens, I didnt pay enough attention to weeding last year and they're all very happy with four or more branches now. I used to rake up all the cones but now I just toss them into the mulch.

Kd

All - The house was a foreclosure we purchased 1.5 years ago (that was vacant for 2 years) and have put a ton of work into, so I've been documenting all my before and after photos :) I'll be happy to share a few.

I lurve before and afters! So many times I just go gung-ho and forget to take the before until we're already well into demo LOL

Here's the first 5 plants I purchased so far. Pics are courtesy of DH. Some are labeled, some are noids.

And the last few.

All together now!

Great selection! Those are going to look marvellous.

Are the cobwebs ones going to bloom? Is that why they are stretching out?

I don't think so. While flower stalks grow from the center of rosette, it looks bit different. I think they could use little more sunlight - some of the 'chicks' looks skinny/etiolated. Maybe pot was shaded by other plants.

Not sure if you know that semps are monocarpic plants?

Rina - yes, I knew they were monocarpic, that's why I was worried about them blooming. The cobwebs ones were on the ground near the table the others were on, so they could be etoliated.

So, I'm pretty sure the cobweb ones are getting ready to bloom! I should finally be able to plant the survivors this weekend. These are technically my first succulent blooms, so I'm happy - but I'm also losing close to half of the cobweb semps :(

It's finally done!

Here's a before - it was a really ugly house, but we saw potential :)

During deck construction:

After deck was built, awning was torn down, house was painted, and border was put in and planted (we've been busy)

Closer pics of the Sedum, Stonecrop, Sempervivum I put in.

Closeup of the cobwebs blooming!

The birdhouse was a Mothers Day gift from my youngest.

Nice job! i think it really turned out well. :) Those blooms are beautiful too!

When we can manage to find some time, we're going to run the rocks down the right side of the deck too. We're hosting a graduation party on the 24th, so we've got a million irons in the fire!

Over the weekend I just happened to stop into a local greenhouse and they had 1 pot with 4 tiny "Oddity" Sempervivum - I was super excited, I've been looking for it! Now I have to figure out where it's going to go - probably down that right side when it gets done.

Mine are much smaller than yours Rina!

Doesn't matter :) - as you can see, mine has grown a lot in less than a year...Wanted to encourage you, I didn't know this will be such good grower. Give it some space and good sun.

Pluto, when I saw what you built I could literally smell fresh cut wood:). Can't wait to see the Semp rock garden all grown in.