Now even though it may not be necessary for robot lawn mower owners, keeping to an effective lawn fertilisation schedule can be very beneficial to your lawn and could give it that extra edge over your neighbours. Just beware you can’t apply it willy-nilly, you should know the types of nutrients your lawn needs and how of them you need to apply, otherwise they could have detrimental effects.
Understanding the basics of lawn fertilisation is needed in order to carry out a successful program, like when you should apply it, how you should apply it and the tools you need to do so correctly. This knowledge will set you on good stead for the season and gives your lawn the best chance of reaching its full potential.
When to Fertilise
It’s best to apply your fertiliser on a seasonal basis as this makes it easier to cope with the varying demands and growth pattern of your grass. Just make sure to check the type of fertiliser you’re using, you don’t want to use one which releases too slowly as you could end up over-applying and damaging the lawn
Feeding the lawn in the early spring will strengthen its roots and gets it off to a good start before the heavy growing season. Plan to apply the fertiliser around about when you first start sending out the mower, so at the beginning of April is your best bet. This of course depends on the weather conditions but a good rule of thumb is to wait until you’ve mown a couple of times.
In the late spring your garden will start to get busier and use up energy so you want to supply it with a suitable feeding for this time. Just watch out, this could mean the same for weeds so you might see a few pop up here and there after applying. To manage this it might be best to use a Triple Action Lawn Treatment instead of a standard grass fertiliser.
Now your lawn is susceptible to heat, drought (maybe not for us in the UK), excessive use and insects so helping it out with a feeding will really do it some good. You’ll normally apply the fertiliser about 10 to 14 weeks after the spring feeding so this will be between June and July.
Again take note of the weather conditions, this will not work if the ground isn’t moist as the salt content within the fertiliser can make these conditions even more stressful for the lawn. If the conditions suddenly change then you can feed the lawn again using either a granular (recommended) or liquid feeder.
Here returns the more suitable growing conditions for the lawn: cool nights, warm days and reasonable rainfall. National temperatures and weather patterns will still apply but as rule of thumb wait until the rain starts in late August or September before applying the fertiliser.
This is the time for your grass to start growing again and is in need for nutrients to recover from the summer conditions. To help the soil through winter, you will want to apply the last feeding just before the winter months, so I recommend the end of October. This strengthens its roots and increase the amount of nitrogen it can store, making for a much healthier lawn for the next spring.
How to Use Fertiliser Properly
Even though on every bag of fertiliser you’ll find a recommended application rate, I think it’s best not to use it, instead I would use half. To prevent over applying and for better lawn coverage, spread the fertiliser in one direction (in straight lines) using half and then spread the second half going in another direction, at a perpendicular angle (90°).
I would cover the perimeter first and then fill in the middle, this will mean there will be a little overlapping but not too much – if done unevenly the fertiliser could burn the grass. If you feel this rate has not been enough then feel free to adjust the amount you use and you can even supplement the feeding with a liquid fertiliser. Just be cautious, overfed grass can turn a blue/green colour and may even promote thatch.
Wet & Dry
As I have said before, you will need to adjust how you apply the fertiliser according to the weather conditions. If it’s wet then growth will be good so you can apply a little higher towards the end of the scale and if dry, but still moist, you can apply a little lower on the scale.
Know Your Numbers
Just like the application rates, on each bag of fertiliser you’re likely to find 3 numbers on it; the first stands for the percentage of Nitrogen in the mixture, the second stands for the percentage of Phosphorus and the third stand for the percentage of Potassium. To make sure you don’t over-apply, make sure you have a pH test done so you know exactly how much of each your lawn needs.
Granules or Liquid?
Out of the two I recommend you go with granules. They are much easier to judge, apply the rates you use and to ensure you don’t overlap at any point. For a nonprofessional it’s difficult to get a consistent spread across the lawn using liquid.
Also when you’re filling up your spreader make sure you do so on a path or driveway. This prevents any granules from gathering in one spot on the lawn, this would just overfeeding, burning and killing of the grass.
Get a good piece of equipment to spread your fertiliser is just as important as choosing the fertiliser itself. You need a quality spreader in order to get a consistent application across your lawn. Don’t cheap out, they will just prove difficult to deal with and are unlikely to give a consistent flow.
The type of spreader is like a big bucket with a wheel at the bottom that projects (or broadcasts) the granules across the lawn in an arch shape. It’s fast and reliable and seeing as you get such a large spread, you won’t have to push it over lawn as much as others.
This model is squarer than the rotary but instead of a wheel at the bottom it just has holes where it drops the fertiliser. Out of all products this is the only one to use weeds and feeds and is good for applying grass seeds, and even lawn sand. Although it can be difficult in tight areas and you will have to be very accurate when using it to prevent stripes.
For homeowners I recommend you use the Rotary Spreader instead of the drop spreader. They’re much easier to use and since they disperse the granules at a wider distance, there’s much less chance of you ending up with stripes, damaged grass and over lapping.
They’re a little cheaper too!
If you found this post interesting then maybe you’d like to see some of my other content, like my robomower reviews? If so then head over to my Robot Lawn Mower Review Page, I’ve reviewed various models all designed for different purposes so if you’re in the market there won’t be a better place to go than here!