Increasing the pH level of your soil is one of the main reasons that people apply lime to their lawns.
But using lime can be much more than a pH modifier for your grass. It can actually help the grass to get even more value from the other products you apply such as granular lawn feeds and liquid feeds.
Alternatives to using Lime on your Lawn
If I’m honest, lime should only be used when you are absolutely certain that you know you need to raise the pH and by how much.
If you are slightly unsure but know you want to improve the composition of the soil, then Calcified Seaweed is a fantastic option to use instead of lime. The large granules are easy to spread, can be applied during the growing season and will significantly improve clay soil types.
Why would you use lime on your lawn
The number one reason for adding lime to your lawn is to modify the pH levels in the soil. Thereby helping your grass to grow better if the soil is too acidic.
Grass thrives in a pH level of between 5.5 and 7. Any lower than 5 means the soil is too acidic and could be producing too much manganese which would be toxic for your beloved lawn.
On the other hand, if the soil is too alkaline (above a pH 7), then it may be starved of phosphate, which is needed for stronger roots and better drought tolerance.
Some other benefits of lime include breaking down heavy clay type soil, which itself is likely to have a highly acidic pH level (lower than ph 5).
When to add lime to the lawn
Once again, only consider using lime if your soil’s pH levels are below 5
One of the best times to add lime is in the Autumn, just before the first Winter’s frost comes along. That’s because it gives the soil time to absorb the material before the next growing season (Spring) when you want your garden looking its best.
There are 2 key rules:
- Don’t spread lime on a dry, brown lawn.
- Don’t apply lime during frosty weather.
Other than those two rules, the only thing to note is what not to do before and after applying it.
Before you Add lime to your lawn – Do’s & Don’ts
While adding lime comes with benefits, there are a few rules to be mindful of before you do the job.
Do Check the pH of the soil
Always check the current pH of your soil before adding any type of pH modifier to the garden. This is super important because it will tell you the right amount of product to be added in order to achieve the desired pH levels.
Don’t apply any nitrogen fertiliser
Don’t apply any nitrogen based fertiliser less than 8 weeks before applying lime to the lawn.
Don’t sow your grass seed
When you amend the pH scale of the soil, it can affect how grass seed germinates. Don’t worry, an alkaline product itself won’t harm the grass seed. However, it may slow down the germination rate.
So, if your patience can’t handle waiting longer than necessary for seed to grow, then it’s recommended to not sow your grass seed prior to adding any form of pH amendment to the soil.
How to Add Lime to your lawn
Mow if necessary
Lime is usually applied during the Autumn or Winter so your lawn may not need mowing. If it does, then it’s best to mow before applying the product.
Scarify if necessary
This may be a part of your attempt to revive the lawn after scarification. Either way, it’s a good idea to reove as much thatch and undergrowth as possible because otherwise, access to the soil will be blocked.
Lime NEEDS to make it down to the soil to have an effect. The quicker it reaches the soil, the quicker the results will happen.
So, think about scarifying beforehand if you haven’t already.
Measure your lawn
Measure the width and length of the whole area, which you want to cover. If the area is larger than 100m2, then you may wish to separate it into equal sections before application.
Calculate how much lime you need based on current pH levels of the soil
Now this can get confusing pretty quickly. ‘Cos it all depends on the current pH level and the desired pH level of your soil.
In other words, the bigger change in pH you desire, the more you’ll need to apply per m2.
As a general rule, 25g per m2 will help modify the pH by a small amount (approx 0.5).
It’s way better to modify little and often than try to modify too much because it’s much harder to get the soil back to normal if you apply too much lime int he first place.
Apply/Spread the lime product
You can buy lime in a couple of different forms. Granualted or powdered.
Some say granulated forms are easier to spread and easier to apply evenly, which is important with anything applied to the grass. However, powdered forms will absorb into the soil quicker.
The most common way of applying is to use a spreader. If you have a small lawn, you can do it by hand, but if you have a large lawn, such as over 150m2, then you might want to use a wheeled drop spreader
Do the application in 2 parts for every section of lawn – apply lengthways first then widthways.
After you’ve added Lime
Once you’ve made your decision to increase the pH levels of your soil and gone ahead and done it, there are a few things to consider.
Don’t sow grass seed
If you want your grass seed to germinate as quickly as possible, I’d recommend you wait for aroun 6-8 weeks. Grass seed itself needs a neutral or very slightly acidic soil to germinate.
Therefore if you make the soil too alkaline, it won’t help your newly sown seed to come to life.
Don’t apply a nitrogen based fertiliser
As in the same way you don’t want to apply a nitrogen fertiliser or lawn feed 8 weeks before, you also need to wait a further 8 weeks after applying lime before applying your next dose of nitrogen fertiliser.