We have a long stretch of very old, very cracked sidewalk in front of out 110+ year old home, so needless to say we also have weeds! I am against using toxic chemicals for several reasons (the biggest being the health of my 1 year old son who plays out there with his little bare hands) so I have been looking for an all-natural, non-toxic way to kill weeds.
I tried simple boiling water first but, shockingly, it barely made a dent! Next up the vinegar/dish soap recipe I keep seeing in various versions. All use vinegar and soap, with some adding lemon juice, salt, or both. For this review I followed this recipe, scaled for my squirt bottle:
All Natural Weed Killer Recipe:
1 cup vinegar
1/4 cup lemon juice
A big squirt dish soap
Instructions: Spray onto weeds on a hot, dry, sunny day, being sure to cover all stems and leaf surfaces with solution. Let sit for at least 24 hours.
It works! I did a small patch and one day later you can see exactly where I did and didn’t spray. I call this a win! MUCH better than the boiling water (how my weeds survived that I still don’t understand, but they did).
Notes about this weed killer:
– Must be applied on a hot, dry, sunny day. The more hours of hot dry sun exposure the more effective it will be. A cloudy, cool day and/or rain will negate the effects.
– Be warned this mixture will kill/damage any and all plants you spray it on, including grass and flowers, so it’s best used in areas where weeds are isolated (like sidewalks) or sprayed carefully on individual plants as a spot treatment.
– Most recipes specify blue Dawn dish soap. I didn’t have that so I used the Gain I had on hand, and it appeared to work just fine (it acts as a surfactant and helps the vinegar cover and stick to the leaves more effectively). Has anyone used Dawn and noticed a big difference?
– The larger the weed the less effective this treatment will be, so start early in spring and always pull as many of the biggest ones as you can before you start spraying. Young weeds/new sprouts are the most likely to be completely killed, while mature plants will eventually sprout back from the roots.
– Since there is no residue left in the soil like with chemical weed killer treatments, new weeds will continue sprout as the summer goes on. Multiple applications (in my experience every 4-6 weeks) will be needed throughout the growing season.
– Exact recipe proportions and ingredients are flexible — different variations probably work best on different weeds (i.e. I don’t need the salt but I’m sure some people and/or weed types do).
– If you use salt be warned that in high enough doses/with repeated treatments the soil may become barren and nothing will grow there, not grass or anything else.