I am often asked when is the best time to scarify a lawn? For the cool-season-type grasses that we have here in the UK the answer is quite simple … only when the lawn needs it and only when the grass is growing strongly enough to recover!
The grass in your lawn has two main growth periods, spring and autumn. This is why experts agree the best time to scarify is the spring or autumn. If anyone tries to tell you otherwise, then they either don’t know the facts or they are just trying to fill their work schedule during slow months!
So, in summary, here is my month-by-month guide to scarifying your lawn:-
JANUARY OR FEBRUARY – SCARIFYING IN THE WINTER MONTHS IS NOT RECOMMENDED!
Your lawn is in hibernation. The cold weather, frozen soil and generally frosted grass will not take kindly to any mechanical work at this time of year. Scarifying in the cold winter months will damage your lawn and it is best left alone.
MARCH – SCARIFYING IS POSSIBLE IN MARCH … WEATHER DEPENDANT!
As the ground warms, your grass will begin to show signs of growth. Depending on how the weather turns, scarifying in March can be attempted. I would take some soil temperature measurements to make sure that the grass roots are warm enough to be growing well. Look for a temperature of at least 8 degrees Celsius and a showery weather forecast and you should be okay.
APRIL – APRIL IS USUALLY AN IDEAL SPRING SCARIFYING MONTH
The soil is warm, the grass is usually in full growth and there is often plenty of moisture around in the form of April showers. However, some spring months have been rather sporadic in recent years, with some being cold and dry. If this occurs in your area, then I would postpone any scarification work until the autumn. April is usually the best time to scarify your lawn.
MAY – IN SOME YEARS, MAY CAN BE A SAFE MONTH TO SCARIFY
As the temperature in the UK increases, the cool-season grasses slow down their rate of growth. Especially if may turns out to be hot. If this is the case, put the scarifier back n the shed. If it is cool and wet, you can scarify, and you lawn will recover quickly. Scarify it too hard though and you risk a ruined lawn for the whole summer!
JUNE, JULY OR AUGUST – AVOID SCARIFYING YOUR LAWN IN THE SUMMER!
Summer is the time when you want to use your lawn, not pull it apart through scarifying. If your lawn is terrible, or you have inherited a new lawn at this time of year, then the best you can do is keep it fed, watered, and weed-free and put off any major work until the autumn. If you must do something, then a summer aeration can work wonders, but refrain if the ground is baked hard with drought!
SEPTEMBER OR OCTOBER – AUTUMN IS THE BEST TIME TO SCARIFY YOUR LAWN.
In September and October the soil is still warm, the air temperature cools and the moisture levels generally rise. All these factors encourage grass into it’s second growth spurt of the year, which means that this is the ideal time to scarify your lawn. This is the time when you can go at it as hard as you can. The Lawn Man promotes overseeding your lawn during this period, so if you chose to do that you can take the lawn back down to soil and re-seed with a more suitable grass. The lawn will sit over the winter and will be absolutely gorgeous the following year!
NOVEMBER – YOU CAN SOMETIMES SCARIFY IN EARLY NOVEMBER, BUT BE CAREFUL!
Temperatures can fall quickly at this time of year. Keep and eye on the weather forecast and soil temperature and decide at the time. If frost is forecast, or if the soil is less than 7 degrees Celsius, then I would put the scarifier in the shed. Also, if the soil is too wet, definitely postpone. If in doubt, stay off it and postpone it until next year or you could do more harm than good!
DECEMBER – DO NOT SCARIFY YOUR LAWN IN DECEMBER
It is too cold and the lawn will be in hibernation and will have no chance of recovery. Stay off it and postpone any mechanical work until warmer times!