my lawn has been over taken by weeds

Question

I have a huge lawn infront and behind my house. I have thought of weed killers but am in Halifax, and there is a law or something about weed killers. It is irritating and I can barely even see the grass anymore. Please am desperately seeking advice, and what I can do, especially now that the cold season is fast approaching. SOS.....

Answer 1

Are you allowed to use pre-emergents? Most lawn weeds are annuals, which means that if you can get a jump on them before they sprout in the spring, then you can cut way back on how many show up that year. That won't help much this year, but if you can't use broadleaf herbicides, the only thing that would probably help this year is a lot of hand-weeding.

If you aren't allowed to use industrial pre-emergent products, there is a corn-based pre-emergent (Cornmeal gluten) that has some marginal effect on broadleaf weeds. Every bit of help counts, I would imagine.

Also, that many weeds probably means you have a soil imbalance and your grass isn't doing as well as it ought to be. A good thick healthy lawn will out-compete a lot of annual weeds. You might look into improving your soil or your lawn care program to help your grass help you keep the weeds down. Some basic soil testing would be a good beginning to help you plan your campaign for next year.

Answer 2

I take it you're in Halifax Nova Scotia? As that's the only Halifax I can find with a ban on herbicides.

From what I understand you are allowed to use some types of herbicides. In Canada there are country wide, province wide and regional regulations. Any herbicides you would typically find in a store in your area I think are going to be approved for you to use as recommended on the label. The only exception is Scott's new EcoSense chelated iron herbicide which Halifax banned but the rest of the province and country did not. You can find more info for Novascotia pesticide regulations. There are some numbers you might want to call if you have any questions.

If you have so many weeds you can't even see the grass anymore it's best to start over. Kill all the existing vegetation (grass and weeds), improve your soil and plant new grass. I did that last year to part of my lawn and you can see the results on my blog here http://www.organiclawndiy.com/2013/08/organic-lawn-renovation-results.html Other posts have more details.

I'm not too familiar with your area but it's getting pretty late and my quick look at your weather forcast makes me think it might be too cold. Fall is generally the best time to put down new grass. If it's getting cold in your area (below 70) you might not be able to do much. If the soil temp isn't 65degF or higher you'll have a hard time getting seed to germinate and some of the herbicides do best when it's hot and sunny.

I think right now the best you can do is find a local lab to do a soil test to see what's going on with your soil. Making improvements to your soil will help the grass grow healthier and help it out-compete the weeds. Have the test done now or sometime next year and plan on doing a major overhaul of your lawn next fall before it gets too cold. Maybe late summer in your region?

There are a number of options to killing your existing grass and weeds including some organic herbicides like I used (which I believe are allowed in your area), solarization which needs to be done in summer but may be difficult if you have a large lawn, you can use a flame weeder, you can use the false seed bed technique by doing something like renting a sod cutter, removing all the sod, adding ammendments (compost, fertilizer, lime, etc) waiting a couple of weeks for anything to grow back then spraying organic herbicides to kill anything that grew.

If I were you, this year I might try:

• Test the soil pH if it's low add the appropriate amount of lime. A soil test will give you an accurate pH measurement but if you're not doing a soil test this year those home pH test kits have been pretty accurate if used right.
• mow the lawn very short.
• Aerate the lawn. You can rent a core aerator that will pull out soil cores, leaving little holes in your lawn. You will need to make multiple passes from different directions so that you wind up getting about 18 holes per square foot.
• Topdress with about 1/4-1/3" of good compost. You'll need 1 cubic yard per 1,000 sq feet. It will help improve your soil by adding nutrients, organic matter and improve the soil's ability to hold on to nutrients.
• spread some good grass seed and hope something comes up. If not, spread more seed after the first hard frost. The seed will lay dormant and germinate in the spring.

Then, in the early spring, if you get grass seed to germinate this year, apply a corn gluten meal fertilizer. It will help prevent some of the annual weed seeds from germinating. If you didn't get grass to grow this year and did the dormant seeding, then don't use corn gluten meal since it will inhibit the grass seed from germinating as well.

It won't get you a perfect, weed free lawn but it should get you a better lawn than you have now and hold you off until you do a soil test, kill it all and start over.