what does lime do for weed

Can Lime on Your Lawn Get Rid of Weeds?

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Many gardeners turn to lime’s lawn-restoring properties when their turf grass loses its vigor and weeds start to take over. Although lime is not a weed killer, putting it on your lawn can help discourage weeds as part of a rejuvenation project and encourage the lush, full growth you’re looking for.

What Is Lime?

When applied to soil, lime can even out the soil’s pH, which is a measure of how acidic or alkaline it is. The pH scale ranges from 0.0 to 14.0, with numbers below 7.0 being acidic and numbers above alkaline, or basic. Lime is an alkaline substance, which means that it will raise soil pH. Agricultural lime is the most commonly available product, made from ground limestone and easy to obtain and use. It is usually composed of calcium carbonate, referred to as calcitic limestone; when it contains small amounts of magnesium, it is known as dolomitic limestone.

Lime and Your Lawn

Lime restores the proper pH balance to acidic soil, which in turn makes the right nutrients available to lawn grasses. Doing so keeps grass healthy, which helps it fend off disease and remain hardy throughout the year. Because weeds are opportunists, they look for any sign of weakness in turfgrass. If grass grows sickly and bare patches begin to appear, weeds often move in quickly. Keep in mind that if you already have alkaline soil, however, adding lime will not help, and could even end up hurting the lawn.

Combating Weeds

The first step in keeping weeds off the lawn is to get rid of them, preferably by hand removal, as herbicide can harm the lawn. Once you do that, you can overseed the lawn add lime if necessary. Before you do, however, you must first establish that a pH imbalance is the problem. To do so, take several samples from around your lawn area and mix them together, then test the mixture using a soil kit. If your lawn is too acidic for good grass growth, lime could do the trick.

Applying Lime

The amount of lime you will need is different depending on your species of turf grass, the starting pH of the soil in which your lawn is growing and the type of soil you have. There are, however, some hard and fast rules. Most lawns prefer slightly acidic conditions, between 5.8 and 7.0. You need more lime for dense, clay soils than you do for loams, and even less for light, sandy soils. Ideally, you should apply it when preparing soil for planting, but you can apply whenever lime is needed.

Can Lime on Your Lawn Get Rid of Weeds?. Many gardeners turn to lime’s lawn-restoring properties when their turf grass loses its vigor and weeds start to take over. Although lime is not a weed killer, putting it on your lawn can help discourage weeds as part of a rejuvenation project and encourage the lush, full …

how much lime to add to soil?

Total Head
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Cali chronic
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Total Head
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Total Head
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Far from a “pro” but I read a lot .

From what I’ve read in other posts, it seems to be more effective mixing it in the soil. There are some posts saying that top dressing may help a bit though. I kinda screwed up and have my conversions all screwed up but I added 2 cups lime to (about) 85lbs of my soil mix, which I think is

5Tbls per 5 gallons. I’ve grown tomatoes in pots in a similar mix and they did considerably better than other soils I’ve used.

Not hijacking your thread but is it possible to o.d. on lime?

Sorry, I’m done taking up space on your thread here but I hope you get it figured out, and good luck.

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well it should delight you both to know that i have a complete grasp of this whole lime proportion thing at this point (notice the date of the first post).

due to my semi-perpetual cycle and limited living space i find myself needing to mix up soil on a per-pot basis. long story short i use around 3 tablespoons per 3 gallon pot (ish). i see some people use less and some people use more, but i find this amount to work for me. i should point out that i use pulverized (powdered) dolomite and not the kind in chunks or pellets. i also no longer bother with ffof soil or chemical nutrients, so ph is pretty much a concern of the past, but the lime is still important in my mix.

as far as after-the-fact liming goes, i highly recommend liquid lime. i find 1-2 tablespoons per gallon of water makes a bigger impact than top dressing with dry lime and watering. it goes to work a lot faster than dry lime and water. i think it has to do with the particles having been run through a finer mesh than the dry lime but i lost the link with the only study i found of liquid lime and potted plants.

as far as ODing on lime, i’ve never done it with a weed plant but i’ve seen it on lawns. you can burn the hell out of a lawn if you use way too much, but the amount i saw used was absurd, so i don’t know what the threshold is.

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Do NOT use hydrated, quick, burnt, or slaked lime. These have all been treated and can burn roots in a heartbeat.

Regular lime is just crushed limestone and won’t burn. Dolomite (Dolomitic limestone), or ‘garden’ lime (calcitic limestone) is what you want.

$4 for a 40lb bag at Lowes or HD

If you’re in the Caribbean, you have it everywhere. Oolitic limestone=ancient coral rock/sea bed. Used it for years in SoFla since that’s what we’re sitting on.


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Im just looking in to this as I also have isues with low soil PH .

I water with 6,5 or so (light green) runn off is normaly 6 (yellow) but lately it have been in the 5ish (oranges)

3 weeks in to flowering I may add ..

and useing a GH drop test kit so Im not 110% on PH levels .. but enough to notice it drop so made a soil test ..

same type of test just for soil and yea .. in the 5ish .. maybe high 5 (5,5-5,9)

but still to low with 4 weeks and lots of nutriens left in my 7 gallon pots ..

specialy one plant do show signs (curling leaves)

so got some Maerl to day (from Plagron)

A popular product in the Plagron range is the Plagron Maerl. This tried-and-tested natural soil conditioner is extracted from coral reefs in the Atlantic Ocean. Plagron Maerl (algae calcium) is rich in magnesium and trace elements and has an extremely high acid binding value. Plagron Maerl offers plants an abundance of essential minerals. The acid binding value is extremely high. Plagron Maerl is ideal for soils with an excessively low pH value. A correct pH level in the soil ensures that the nutrients in the soil can be maximally absorbed by the plants.. Plagron Maerl contains: carbonic acid magnesium calcium, acid binding value 54% and 9% magnesium oxide, soluble in mineral acid.

The dosage of Plagron Maerl depends on the type of plant and the pH value of the soil.
Usage in full soil: 5 to 12 kg per 100 square metres.
Usage in potting soil: 250 to 500 grams per 1000 litres, depending on the plant being grown and the acidity level of the potting soil.

18$ or so at my local grow/hydro store ..

was looking for Dolomite lime as I read about that evrywher ..

but did`t have that . had this insted .. nice sales person said he use it and its about the same just from another source ..

so now Im looking in to it to see what exatly it is and how much to use aso.

so I just found this “old” thread .. guess somebody els will look for this info aswell .. and since it seems to be impossible to find any info on this product or any other reef coral lime .

I was thinking to make some

will add it on top of my soil (only way for me in my 7 gallon pots 3½ week in to flowering)

from what I can read and with my limit mat skills .. I schould use 25-50 grams per 100 liters of soil ..

I got 27L pots .. maybe with 25 liters in them ..

I will try in the low ranges fist and see what happen .. so 25 grams per 100L = +6 gram in my 25L

after “shaking it all over my soild I water with normal 6,5PH water (with a low ½ strengs nuts solution .. my plants are hungry)

a pics of my small bud leaves:

notice the curling .. hopeing the new grow will look more normal now when/if I get my PH up in the 6ish ..

I will update this with more info and pics ..

i always seem to have issues with ridiculously low runoff ph (below 4 sometimes)even though I always make sure the ph of the water or nutes is around 6.5-7…