"we refuse to use store bought herbicides, due to the fact that they may be linked to the declining bee population."

It is not only bees, all insects are on the decline https://www.nytimes.com/2018/11/27/magazine/insect-apocalypse.html?fallback=0&recId=1DwHTvfX7hol9BakTuJDwFgNSmg&locked=0&geoContinent=NA&geoRegion=MI&recAlloc=most_popular&geoCountry=US&blockId=most-popular&imp_id=732344360&action=click&module=Most%20Popular&pgtype=Homepage

Maybe compacting the soil would work?

I use 50/50 bleach/water in certain places...driveway cracks, crushed granite etc. It works well, not perfect, but I feel it's better than Roundup for me and the environment. Anywhere you have soil, weeds will eventually sprout, although the bleach may eventually make the soil inhospitable.

A blow torch works well to kill weeds in between rocks, bricks, pavers.

oooh, a blow torch could be fun. I can only imagine what my neighbors would think, lol!

@windberry - yes. so sad. I try to be as conscious as I can. to make yardwork even more difficult, I have to also factor in how storm runoff goes to our sound and pollutes it. so I even found myself overthinking "natural" solutions like vinegar. there is no easy way really.

I think I'll just have to be aggressive with vinegar and my weed whacker. ugh. our yard is too much!

Sorry, but nothing will kill weeds permanently. Not even covering the ground with concrete. And if you have run-off issues emptying into any body of water, you want to avoid salt. It probably does just as much harm to the environment as any commercial pesticide.

Weed torches (not actual blow torches) are very popular and available just about anywhere....no reason at all for your neighbors to be surprised.

Vinegar only works well with annual weeds. It is not transmitted into the root system so will have no long term effect on perennial weeds. And it needs to be used while the plant is in active growth and with sun to be effective at all.

It's not easy to grow plants or weeds on a dry stack boulder wall unless they stay constantly wet or something is growing down them from above. There are so many unknowns here, like where you live climate wise, what this " midcentury wall" with no mortar really is and what are these plants or weeds you are actually dealing with. A picture would be most helpful.

I commend you for considering what effects the chemicals you use can have on the larger environment. However, it is quite possible a no chemicals at all, mundane habit of maintenance or some permanent cultural fix to your yard would solve the problem. I'm having a hard time wrapping my mind around having to weed whack a dry stack boulder wall.

I think I will look into that torch after all. we have about a mile of sidewalk weeds to deal with too, and torching could be really fun! the weed situation doesn't look too ridiculous right now, but in the summer, it's crazy overgrown. this is Seattle, where nature tries very hard to reclaim everything. plants will grow out of your car if you let them.

I'm thinking of transplanting a healthy fern from those rocks (if you enlarge the pic, it's way off to the right). does anyone know if that's even possible? it's growing out from between the boulders. it's beautiful, but my husband thinks it encroaches on the sidewalk too much and sadly hacks it back.

Climate wins. You can grow all kinds of things in your dry stack boulder wall. The weed torch is probably your most eco-friendly choice. Moss in this situation can be your friend. It will act like a mulch/weed seed barrier and slow things from being able to take hold.

Yes that fern should transplant very easily.

I LOVE moss and plan on encouraging it everywhere! (except for the sidewalk, which I will get to eventually.)

Maybe not as easily as thought :-) Native western sword ferns - what that is - have dense, deep root systems that defy easy transplanting. Although how deep that may be in a boulder retaining wall is up for grabs!

Once you have the weeds out of the wall consider planting it wth something of more aesthetic value - hens and chicks, sedums and various rockery plants or even some groundcovers will fill all those nooks and crannies rapidly and keep most of the weeds out. And require very little actual soil or root space to thrive.

"all insects are on the decline."

Good.

It would look a thousand times better with decorative plants in the gaps than with just rocks and nothing else there.

If it were mine I'd have lewisias all over that thing.

Exactly. To me that is not a problem area but a potentially exciting new plant habitat. There are so many beautiful plants which would love that wall.

"Bad.....very bad!!"

Of course, I was just kidding, for the very reasons you mention, Gardengal. But, in spite of the joking I wouldn't shed a tear if the vast majority of the bad insects -- the biting, non-honey-producing-stinging ones -- went "south." Mosquitoes and biting flies mainly. I'm all for wax, honey and lacquer.

Meanwhile climate change means disease carrying species of mosquitoes and other warm climate nuisance organisms are actually coming farther north. Or are expected to later.

The worst effects from the raising of the average temperature have been seen so far at the poles, where already the far north is having huge damage from bark beetle outbreaks. This zone of conspicuous destruction extends all the way down into mountain conifer forests in the lower 48.

I'm still processing the comment about not wanted to use a product that's been approved as an herbicide, so they use chlorine bleach instead. That's... not necessarily better.

the reason why I don't want plants back there is because our property in general is proving too time consuming to maintain. that rock wall is behind our house and we rarely go back there. I think it would look perfectly good with no plants. most of our time is spent keeping our front area clean - there are tons of pedestrians going by every day. we don't love gardening, and we're struggling to simply keep our property from looking feral.

thanks for all of your comments, y'all! here is what my approach is going to be:

1. put weed barrier fabric all along the top of the rock wall, and cover it with small rocks. 2. hire some routine cleanup help just for the back side of the property. then maybe we'll actually have time to do some fun landscaping in the rest of our yard, finally!

Your plan sounds reasonable given your current situation and needs.

Here is a wild idea you can take for a ride if you like. Seattle and the PNW is a gardening mecca full of gardeners. Is it at all possible there is a gardener or garden club in your neighborhood who have run out of room for more plants. Is there a neighborhood list serve type thing? Why don't you put your wall up for adoption. See if you can find someone who would love to plant it. That will really impress the neighbors. One out of a ton of those pedestrians could be a gardener.

My advice is, remove the biggest weeds only and clean up the top of the rock wall and the sidewalk (it really looks bad) first. You may be surprised how different overall appearance of the whole thing (sidewalk and the rock wall together) will be. Then decide what to do with that wall. May be you will like the little weeds growing there. Bees and other insects will love them, too.

The weed fabric covered in stones isn't a great idea. It will soon be a nursery for weed seedlings, I'm afraid. It just isn't possible to keep an area weed free long term with no maintenance.

Since it is very visible along a public sidewalk, I would not leave it unplanted. It will just fill up with weeds again in a couple of weeks. Plants that grow well in rock walls like this require very little maintenance once planted. And once they fill in, weeds will not be much of an issue. You will spend more time or need to hire help more frequnetly to keep the area weed-free than if you were to plant it.

These types of boulder retaining walls are dead common in most older Seatle neighborhoods. And we are rapidly coming to the time of year when rockery or wall plants pop into a profusion of flowers!! I'd look at candytuft, rock cress, campanula, creeping phlox, creeping thyme, basket of gold, lithodora or sempervirens (hens and chicks) or any of several dozen creeping sedums/stonecrops.

I may have been confusing with my last post. I have a front yard, backyard, and that rock wall. the wall is behind the backyard. we literally never see it unless we walk way out of our way. that street is super tiny, it gets very little foot traffic. it's hard to tell from the photo, but that wall is pretty big. it's 2x as long as you see in the picture. you can't reach the top w/o a tall ladder. (do you want to haul out a long ladder every other weekend just to weed? I don't.) the sidewalk is 100' long and has weeds in every expansion joint. it doesn't look very overgrown right now due to winter, but in the summer it gets crazy, really fast.

the public walkway that does get a lot of foot traffic is the front of our house. I was saying that it's also long and needs tons of frequent maintenance so we rarely have enough leftover time to spend anywhere else. we would love to plant more flowers for the birds and pollinators to enjoy in the parts of the yard we do see, and would have time if only we could just make that rock wall easier to deal with.

regardless, I got my answer: no, it's not really possible to prevent weeds coming back w/o using scary sprays. so I'm going to put weed barrier cloth at the top, and hire some routine maintenance for just that area. thanks for your feedback!

I've seen walls like that covered by Cotoneaster dammeri. It's a little slow to establish itself, but does a nice job with a little maturity. I'll get a picture of one in a few days when I can get out of my 1/4 mile hilly driveway because of the snow.

Mike, if you need to get out and about, better do it now!! We are going to get dumped on again, starting early Friday and continuing into Saturday, and it is predicted to deliver as much, if not more, as we got on SB Sunday. Not only that, they predict additional accumulations with more snow coming early next week!!

I guess all that gloating we PNW'ers did when the eastern half of the country had major cold and snow issues a couple of weeks ago is over!! WSDOT is predicting the worst snow event here since December 1996. It is also predicted to stay very cold for the foreseeable future, barely cresting above freezing during the day and dropping to the low 20's or teens at night.

As soon as any organic debris - including fallen leaves or deliberately applied organic mulch like decorative bark - accumulates on top of weed fabric and then decomposes the weed suppression is over. Rocks placed on top of weed fabric make it infinitely more difficult to clean and walk on. And you would have to somehow install curbing on top of the wall there to keep the rocks from migrating, spilling onto the pavement below.

Distaste for or inability to do yard work is supposed to be a main driver of the townhouse market. (I've also noticed these seem to be a lot cheaper than single family homes). If your current situation is too much work for you maybe you need to consider a different one - there is no magic bullet that is going to make it so that that wall never sprouts weeds. And same with the rest of your property. It depends partly on what specific approach you are taking to each component of the garden and if these components have been designed and organized to require less work than there might be with another approach. For instance your statement about being tasked with having to keep a particular area clean all the time suggests you might not have used techniques like mulching or dense planting to reduce upkeep. That instead you might for instance have exposed soil that you are having to groom over and over, because it is acting as a seed bed for new plants.

Regarding the current local weather the Cliff Mass weather blog has details.

BF

Stick with your plan. Everything will be fine. And don't forget, you can always put your wall up for adoption to a needy gardener.

It looks like it will be awhile before I can get out to take that picture of Cotoneaster. We got dumped on pretty good yesterday evening. Still dark out now for a picture, but it looks as if it's at least a foot with more to come. Since I'm a hermit at heart I'm set up to hunker down for quite some time. I heat with wood and have plenty of gas for the generator if the power goes out.

B F, if you don't plant something to hold the soil behind the rocks it will eventually fall out and weaken the wall. I've seen Hypericum or Vinca minor used on walls like yours and seems to work for people who are not into gardening or who want low maintenance. Most rock garden plants like sedums, sempervivums, echevarias, and Lewisias aren't vigorous enough to suppress the weeds unless well established, and that takes considerable time and a lot of weeding.

Mike here is a picture of Cotoneaster dammeri 'Streib's Findling' covering a stacked boulder wall. Enjoy your snow days.

According to the 2014 edition of The Hillier Manual of Trees & Shrubs (Royal Horticultural Society, London) 'Streib's Findling' is

"Sometimes said to be a hybrid of C. dammeri to which it bears no resemblance. It is possibly a form of C. procumbens"

The Cotoneaster section of the Manual was contributed to by Jeanette Fryer who is probably the leading western authority on the genus at this time.

Embothrium I think we have been through this before. You very well could be right. I personally don't care what its proper name is. It was sold to me and labeled as Cotoneaster dammeri 'Streib's Findling' by Monrovia out where this wall is should someone be interested in finding it in a nursery.

https://www.monrovia.com/plant-catalog/plants/1006/streibs-findling-cotoneaster/

The Cotoneaster in your pics looks spectacular Christopher. Is it in your garden?

Thanks windberry. This is in a client's garden. It's not quite so spectacular in my garden on the steep slope I have it growing on. I don't have the million dollar stables above or the sheer drop for it to fall over.

https://www.amazon.com/Red-Dragon-VT-2-23-000-BTU/dp/B00004Z2FP/ref=sr_1_2?ie=UTF8&qid=1549824021&sr=8-2&keywords=weed+dragon

I have one of these. Works fine as long as weeds are small. If big you have to go over them several times. You don't burn them totally off, you just wave the heat over and it disrupts the leaves. Be careful around the wood fence. I use a 20 lb tank on a cart instead of the little bottles. Yes the stuff will sprout from roots for awhile, but if you keep after it even well established dandelions will die from lack of food.