soap, baking soda for crabgrass

laffterAugust 5, 2009

I've read about some success fighting crab grass by spraying it with soapy water, then dusting it with baking soda. My main question is: how do you apply the soapy water? With an ordinary kitchen hand sprayer? and what kind/how much soap?

Thanks. I'm working on treating a wildflower garden that is overcome with nasty crabgrass.

Thank you for reporting this comment. Undo

I'm not finding anything about using soap and baking soda to control crab grass. If you have links to what you have read post any here, but those articles you read should have had the application method outlined.
Crab grass is an annual grass that is pretty easily controlled with a good mulch that covers the grass really good, or by pulling the newly emerged seedlings from the soil.

    Bookmark   August 6, 2009 at 7:54AM
Thank you for reporting this comment. Undo
dchall_san_antonio(8 San Antonio)

I'm the one that has been spreading that news. Several years ago I had heard of this approach. I presented it here and on other forums but nobody ever tried it. Finally Cactus tried it and took a lot of pictures. I'd link you to the forum where he presented it but that's not really polite and I'm pretty sure GW blocks links to that forum.

Here's a link to the youtube video that really shows how to do it. How much soap and molasses has been figured out by Cactus.

Suffice it to day baking soda will kill crabgrass in a day or two; HOWEVER, it might also kill your grass. The results are not in for all grasses but for St Augustine, it works GREAT! St Aug is only slightly affected by the baking soda. Subsequent photos posted by Cactus show the St Augustine recovering nicely after 30 days. After Cactus' report hit the forum, Andy tried it on his grass in MA. He reported that the baking soda test killed about 75% of his northern mix grasses. So there is good news here for northern gardeners. If you are not worried about the surrounding grass, like in a flower bed, baking soda will kill crabgrass every time. The reason for the soap and molasses is to pretreat the hydrophobic blades of crabgrass so the baking soda will stick.

    Bookmark   August 7, 2009 at 2:46AM
Thank you for reporting this comment. Undo

If the crab grass is growing in a flower, or vegetable, bed either covering it with a mulch (once that grasses access to sunlight is halted it will die) or simply pulling it out is better then spraying it with anything, especially anything that will also kill other plants.
If the crab grass is growing in the lawn, any spray that will kill that will also kill any other grass the substance touches, leaving large brown spots for some time which could allow more crab grass seeds to germinate, or other "weeds" to grow to fill in that bare spot.
Since most all crab grass is an annual understanding how it grows and then fixing the conditions where it could grow is a better solution then spraying any poison around, and if those products do kill plants they are poisons.

    Bookmark   August 7, 2009 at 8:05AM
Thank you for reporting this comment. Undo
dchall_san_antonio(8 San Antonio)

I think the reason the baking soda works in a St Augustine lawn is that St Aug is extremely tolerant of salt.

I agree that mulching it in a flower bed would be preferred to anything else.

    Bookmark   August 9, 2009 at 3:29AM
Thank you for reporting this comment. Undo

Hi everybody..I live in the Palm Springs, Ca area and I was glad to find a forum on this subject because I suffer from major crabgrass issues in my new vegetable garden. Just wanted to ask how much mulch should I put in to smother them little buggers? I am scared to try the soap or baking soda as I do not want to hurt my very first veggie plants...:-) Thanks everybody!

    Bookmark   April 7, 2013 at 4:24PM
Thank you for reporting this comment. Undo

Lisa, you need enough mulch to deprive whatever plant you do not want growing there to not get the sunlight they need. That means a minimum of 4 inches of shredded leaves in my experience, or a layer of newspaper or cardboard down first and covered with another, better looking, material to hold the paper down. The newspaper or cardboard simply allows you to use less material and get the same results since about 2 inches of a mulch, shredded leaves, wood chips, straw, etc. is enough with that paper down.

    Bookmark   April 8, 2013 at 7:30AM
Sign Up to comment
More Discussions
So how out of touch are we????
Years ago, during one of those PBS marathon fundraisers,...
Increasing height of celebration bermuda
Our lawn was sodded with bermuda celebration a bit...
Planting Clover Stolons (or Any Stolons Really)
Has anyone ever tried to transplant clover or a stoloniferous...
Is It to Late in the to Apply Organic Fertilizers in Zone 5b
The condition of my lawn: The lawn is thick, but lacks...
Organic Lawn Care FAQ Cut Off?
The Organic Lawn Care FAQ seems to have gotten cut...
Sponsored Products
Set of Four Boat Details Italian Marble Coasters
$59.50 | FRONTGATE
Pro Mat Silicone Baking Mats (Pack of 2)
Kraus KBU14-KPF2220-KSD30 Single Basin Undermount Kitchen Sink with Faucet - KBU
$439.95 | Hayneedle
Etched Matte Stainless Steel Bath Accessory 4-piece Set
Home Decorators Collection Cabinets Templin 28 in. W Wall Storage Cabinet in
Home Depot
Bolla Mosaic Outdoor Console Table - 28-9203
$299.00 | Hayneedle
Teak Shower Caddy with Removable Soap Dish
Signature Hardware
Rectangle Tidy Table Cover - Set of Three
$8.99 | zulily
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™