Weeds in Sidewalk expansion cracks
I live in a sub-tropic area in which weeds seem to appear overnight and grow taller than the house by the time I get back from work. They especially like to root in the expansion cracks in the sidewalk and driveway. I have used products like Roundup which may kill them in 2 weeks, but the weeds soon appear once again after heavy rains.
Is there a more permanent solution? I have actually thought about… don’t laugh… putting a bead of clear silicone caulk in the joints. Or, is there something better?
they make a concrete chaulk just for that.
Have you asked at Over the Fence?
bobl Volo, non valeo
Baloney detecter WFR
Isn't there a somewhat new type of Roundup that essentially poisions the soil and is advertised to keep vegitation away for a year? Or how about as was previous mentioned, power washing the dirt out of the control joints and then filling them with SL-1 caulk.
"Or, is there something better?" I'd use a one part self leveling polyurethane such as Sikaflex-1C SL. Kill the vegetation and clean out the joint well. If the joint is wide you'll need to use foam backer rod. Sikaflex-1C SL is self leveling or pourable so little or no tooling is required. It's worked well for me.
The product you are thinking of is "Triox." Now marketed under a variety of names, it has worked well for me in the same use.
Unlike Roundup, Triox comes as a concentrate, and must be diluted. In my experience, it works for well over a year.
The sealants others have suggested are a more permanent solution.
Salt.Sprinkle salt in the joint and mist it with water. The salt will leach in to the soil.
After the Romans conquered the Carthaginians they added insult to injury by salting their crop fields.
For my own concrete driveway, I use a technique not embraced by environmentalists … I pour a 2 cycle mix of gasoline & oi) into the cracks. Usually “protects” for about a year. Rookie
Be very careful about using any persistent weed killer that acts through the soil. Generally speaking, the stuff can also kill or weaken tees and shrubs. You can't see them, but tree and shrub roots can extend far beyond the so-called drip line. I have seen roots as much as 20 feet beyond -- even with relativey young trees only 20 or 30 feet tall.
Second the table salt,
It starves plants, rather than poisoning them.
Will need more than one application to bind all the nutrients in the cracks to the salt.
roundup? Gasoline? Yea, try the salt first. Also, boiling water apparently works too, though I doubt you get much long term benefit from that.
I like the idea of oil/gasoline in the cracks - except I'd have to post "No Smoking" signs. I actually ran to my local building store and found some poly-urethane caulk, concrete sealant, and self-leveling. I put it down yesterday evening... and realized that I had not bought nearly enough (isn't that always the case?). Now, onto the actual garden. Do those weed blocker sheets really work?
Thanks for all of the feedback!!!
>>Do those weed blocker sheets really work<<
"Do those weed blocker sheets really work?"no
bobl Volo, non valeo
Baloney detecter WFR
I've been pulling all the weedblocker fabrics in my gardens. I used bark mulch over the fabric and the weeds love it. The desirable plants seem to like it, too. Everything sends fine surface roots through the fabric, it will become a thick mass of fine roots in no time. It's like removing sod. The moles also like it, there is an amazing network of tunnels under the weedblock. These are often moldy. The stuff has never worked for me and I've used many different types. After the first few months, it just seems to cause problems.Beat it to fit / Paint it to match
My landscaper recommends using Preen instead of weedblock fabric.
I'd use "total vegetation killer" (Triox). Roundup is not intended to be a long time solution, in fact you can plant a week after application.
On, the other hand, homemade napalm would offer a spectacular, but also temporary solution.
Napalm? We'll have a Barbeque. Who's bringing the beer?
Now you're talking. I'll bring a keg. Have you got the kegerator?
That or Plutonium Plaster.... ;-)
Seriously, though, salt is also good for getting rid of thin-leaf weeds like dandelions and grasses mixed in with succulents like ice plant. Spray on a saturated solution of magnesium chloride when it can have a few days without rain to wash it away.
You could buy a flame weeder, which hooks up to a regular propane tank, and is an absolute blast to use and a good excuse to buy a tool that spits fire.
I have used concentrated vinegar for weeds in cracks, it doesn't work as well as roundup but you can dump it on with no worries. A big jug from a warehouse store is pretty cheap, too. Pour it straight from the jug or put it in a spray bottle -