Replacing our lawn with DG in SoCal

We are replacing our front and back yards of about 2000 sq. ft. of misc. grass and weeds with decomposed granite. The workers mechanically removed the grass and tilled what was left. They just left, and we are seeing lots of roots still in the soil. We intend to put about 2 -3 inches of DG on top combined with large pavers, cacti, succulents and dymondia in some areas for ground cover. Our property is completely flat with no erosion issues at all. The big QUESTION IS... How to keep the grass from comming back?
We had thought of using "Layout Board" (a thin non-corregated cardboard used in the film industry to protect floors when setting up sets and shots in sensitive locations) instead of weed barrier fabric. We've heard that weed barriers sterilize the soil underneath, which is not our intent in the slightest. The layout board will theorecically stifle the weeds in the interim, and then decompose over time while allowing water to drain into the water table while the DG gets stable. Any thoughts?...

I'm not able to answer your questions, but I'll bet someone in either the Beginner Landscaping, Garden Design, or Master Gardeners forums will. If you don't get many responses here, post your questions there and see what happens.

I hope you post pictures when you are done! I would love to see your new cactus and succulent garden! Sounds like it will be great.

did you end up using the layout board? seems like that would work.

Hi, Aheim.

I just had DG installed in a large area, but also had a stabilizer sprayed onto it which mimmicks that of the relatively new 'Terra Pave' product (they may be the same but I don't know. The Terra Pave stuff is liquified pine pitch. Weeds were one reason for installing the surface, having dogs who'd drag shredded redwood into the house. Needing to replace weedcloth every couple of years. This method makes weed cloth not needed. But it is more expensive.

The installation required them digging down about 4" through the top soil surface. They needed to grade it so the water drained in the proper place. They placed 2" or so of road base on the soil beneath. Tamped it down with an electric tamper. Then added the DG, tamping it also. Final step was sprinkling the liquified pine tar pitch onto the surface.

[Much to my chagrin, the bizarre late rains here in the Bay Area interrupted this whole process, and made what should have taken a couple of weeks into a 6-7 week ordeal, waiting for the DG to dry in order to apply the stabilizer.]

The reason I chose to go this more expensive route instead of regular tamped DG is because I'd seen several DG installation with weeds. Here in CA, a popular strategy is using a wand torch to kill them so you don't have to use poison. Also, my dogs romping on the 'regular' DG surface would constantly degrade the surface over time, whereas this is firmer. And, it can be blowed to clear off debris from surrounding trees, without blowing away surface. Mine is gold, which is lovely in the rustic setting--seems natural.

Hope this helps.

Karen

i had plastic sheeting laid under the dg i put down years ago and have had no weeds ever since. however the dg is wearing away and will have to redo soon.

I don't have anything to add, but am curious as to what your yard ended up looking like, and how well it will hold up over time. Please keep us posted.
Walk In Beauty~
SingingWolf

Thanks for asking. Our project turned out very well initially. We're glad we used the layout boards which worked out well in most places. We kind of ran out of material (i.e. 4x8 sheets) and used bits of scrap that we had cut to make other sheets fit.
WELL...unfortunately, those areas were we were using the scrap pieces has clover coming up. Also, the areas where we planted the Dymondia between our pavers is also overrun with clover. Everywhere we had planted plants in the DG has clover growing in vital abundance. Not what we envisioned for our landscaping project.. There is one area where we didn't overlap the 4x8 sheets of layout board where the clover is sprouting up in "nice" straight and right angle lines.
Overall. I'd say the layout board works well. Just be sure that they ovelap, with NO open areas to the base dirt. Literally, any crack in the barrier (layout board) weeds can grow, they will.
Our Dymondia is being outgrown by the clover, and hence shadowed. The clover has beat out the Dymondia in a few areas. It takes vigilance to keep the clover at bay to let the other ground covers to exist, let alone flourish.
Right now (mid November) the clover is our main concern. We'll start a new thread dedicated to dealing with clover. Now that we have no "lawn" comprised of many different kinds of plant (weeds), the clover has no competition and has the opportunity to run amok.
Any suggestions from anyone?

Can you possibly take a photo of what you're calling "clover" ?
It sounds like what you're batlling is Oxalis...a horrible weed here in So. Calif. that will take over any given area very quickly. It has tiny conical seedheads about 1/4" long that explode when you touch them and send seeds flying...which germinate almost overnight.

This stuff will grow in sun or shade. It will come up in places you'd never think anything could possibly grow. It spreads by runners as well as by seed. One surefire way to erradicate it is to use RoundUp...but that will also kill everything else it touches. As daunting as it sounds, digging it out by hand and then applying a pre-emergent weed killer is about the only way to get it under control. The RoundUp won't kill the seeds that are in the soil, it will only kill the existing weeds. Unfortunately, it's also one of the few weeds that Dymondia won't "choke out".

That doesn't sound encouraging. Here's one picture with 'that stuff' around one plant, a red flax

This is a picture of the clover "dominating" the Dymondia.

and this is a picture before

Glad you posted the pictures. What you have IS a type of Oxalis, but not the one I was referring to. You have "Oxalis pes caprae" also known as Bermuda Buttercup. Unfortunately, it too is just as difficult to get rid of. In spring it will get clusters of yellow flowers on it...which "can" be pretty. But, the blooms are sterile, so it doesn't spread by seeds. You pretty much have to hand dig this one, too...sorry ! They have a long tap root with a small "bulblet" on the end...which usually breaks off when you're digging it...then it resprouts.

However: It IS controllable if you are vigilant about hand digging it out the minute you see it.
Eventually it will give up. The bigger you allow it to grow, the bigger the bulblet will get, which means it's more likely to return. It shows up when we've had a lot of rain but normally disappears when the weather gets warm. There were probably bulblets in the soil just waiting to sprout when you started the project. Get out there asap and start digging !

Use one of those weeder tools that looks like a screwdriver with a V cut into the tip.

Yep, Oxalis is a challenge. I’m slowly winning the battle but still digging it out one plant at a time in my dymondia. You do have to gently follow the root runners and get them all. I think my Oxalis must be the one with productive seeds as it pops up in new places, even in potted plants.

I am starting to use RoundUp to try to eradicate it completely, along with the dandelions, and have found a couple of different methods to apply it without getting it on anything else. For small weeds use a watercolor type brush, say ¼” across, or even a cutip, and paint in on some of the leaves of the offending plant. Make sure it isn’t dripping. For larger offenders, like the baby Brazilian Pepper tree sprouts that pop up throughout our ivy covered bank, I use a cardboard tube. I found a 5” diameter one and cut it to 3’ (the top height of the pepper tree sprouts). I put it over the sprouts making sure all the plants below are pulled out of the tube at the bottom. Then I spray the offender, not too generously as I don’t want it dripping too much, and after letting it sit a minute or so remove it making sure to lift it straight up. This method has worked very well and we’re down to a dozen or so sprouts each year vs. 50+ before.

Seems like you could do the same thing with the Oxalis by pruning your lush weeds back a bit and using a shorter tube, perhaps even making one our of multiple pages of newspaper shaped to size. If it’s too close to the Dymondia you could cover those little mounds with pieces of cardboard with a rock on top and leave it on until the RoundUp has dried.

Your before picture looks like a lovely design and the dymondia will fill in before you know it. Ours is in-between flagstone stepping stone covering about 600 sq. ft. I wasn’t sure I’d like it but after the six months it took to almost completely fill in it looks really nice and needs very little water.

Hope you share some more pictures later. Good luck!

Thank you for all the detailed information. We started the hand removel technique, and are using round up for larger areas away from other plants. Sometimes I use clear party cups with the bottom cut off to isolate the weeds, but the tube technique is a good idea too. In some areas the bmuda btrcp. has overrun the dymondia making it mouldy and mushy. I hope it's not too late for the little buggers. It's a long wait for those hot, sunny SoCal days to burn them out. I know they'll probably come back the next Fall anyway.....

Oh wow, I have that Oxalis stuff too. I also thought it was clover and 'pretty'. It does seem to grow in most places, including pots, but in particular like to grow near the Gardenia bush which gets the least amount of sun and gets watered the most. Have a big batch of it now. I have just been pulling it up, but will dig it out now. The goats love it. The horses would eat it too, but don't want them to have the dirt on the roots. They want to be out 'grazing' in my garden.

If you are using the tube or cup separately for each plant you want to kill, you can save a lot of time and effort by attaching the shield to the Sprayer tip. Roundup works by killing the root, so you do not need to spray every leaf on a plant to kill it. Also, I did not like to use the one i bought, but there is a device shaped like a Hockey Stick, with felt around the bottom that gets damp from the solution soaking out. It does not drip much, if any, and the liquid is stored in the handle. The felt is damp, so you just wipe the offending plant with it, and that does the job.