Automower Spiral Cut: How It Works and What It Does

During my research about the Husqvarna Automower I recently discovered that the existing online information about the rather interesting spiral cut function is quite poor. So I read up on the topic and would like to explain what it is, how it works and what it is good for.

How does the Automower spiral cut work? The Automower spiral cut is a function of some Husqvarna Automowers that is used to quickly mow a specific area. In places where the grass is particularly high, the robotic mower moves outwards in a spiral from its position to cut the grass here as quickly and efficiently as possible.

In the next sections I will explain to you exactly how the Automower’s spiral cut works and what it is good for.

How Does the Spiral Cut Work?

The Husqvarna Automower normally drives randomly through the yard. Although they have various additional navigation features, such as navigable waypoints on the guide wire, or assisted navigation via GPS, they still mow randomly.

The spiral cut is a special function of some Automowers, which the robotic mower can either do automatically if necessary, but which can also be started manually. In automatic mode, the robotic mower activates the spiral cut when it gets to a place where the lawn is particularly high, for example because no mowing has taken place there for a while. The spiral mode then enables it to cut the grass only in this area.

The Automower does not measure the height of the grass with a built-in ruler, but by means of the resistance measured on the mower deck. If it is more “strenuous” for the lawn robot to mow the lawn, it concludes that the lawn must be higher than usual. Of course, it is also possible that you simply have a particularly robust type of lawn. For this reason, the sensitivity from which the robotic mower should switch to spiral cutting can also be adjusted.

As soon as the robotic mower has changed to spiral cutting, it moves outwards from its current position in the form of a spiral and thus mows the entire area it is currently in. You can set which mode it should switch to when it has completed the spiral cut.

To Start the Spiral Cut

You can either start the spiral cut manually, or configure your robotic mower to switch to spiral cut if necessary while mowing.

Manual start: You start this with the START button. The manual function is useful if you notice that a certain area of your lawn needs urgent mowing because the lawn has become very long. There may also be an area of your yard that you rarely mow.

In any case, you can carry the Automower to the appropriate spot, press the START button and command the robotic mower to mow the spot quickly in spiral mode.

When the robotic mower is finished, you can choose how the robotic mower should proceed. You do this by pressing the right arrow key and then selecting Main area or Secondary area.

What Are the Settings Options?

You can set the intensity of the spiral cut. There are the settings Low, Medium and High. Low means that the spiral cut is carried out less frequently, while high means that the spiral cut is carried out particularly frequently or the lawn height does not have to be far above average to need a spiral cut.

Of course, you can also switch off the mode if you do not want to use it at all. All these options can be found in the menu under Settings -> Spiral Cut. There you will find the menu items On/Off and Intensity.

What Are the Advantages and Disadvantages of Spiral Cutting?

The Advantages

The biggest advantage of the spiral cut is that it can be used to quickly restore areas in the garden that, for whatever reason, have not been mowed for a while and are therefore too long or uneven, to the correct height. In random mode, the robotic mower would take a long time to mow away everything in a very specific area where the lawn is too long.

Another advantage of this is that the robotic mower saves time and energy, because it can be used to mow areas that are too long, thus automatically reducing the total time required to mow the work area.

Also in cooperation with GPS navigation the spiral cut is a great thing. A robotic mower with GPS plots in its internal map and remembers when and where it last mowed. If it finds that it hasn’t mowed in a certain area for a while, it can drive to that area and quickly mow the coarsest part of it in spiral mode.

Another advantage is that you can cushion large differences in growth of your lawn with this function. For example, if most of your lawn grows slowly because it is in shade, you can adjust the frequency of mowing to match the growth of your slow-growing lawn. The Automower will still mow your fast-growing lawn well because it automatically applies the spiral cut.

The Disadvantages

The spiral mode does have some disadvantages, however. One problem, for example, can be the rather long lawn cut if the lawn is particularly long or has not been mowed for a particularly long time. Of course, this problem does not arise directly from the spiral mode. However, it may tempt you to mow certain areas infrequently and then quickly take care of them in spiral mode.

However, this results in quite a long lawn cut. Since the robotic mower works with a mulching system, the lawn cuttings are not collected, but remain on the lawn to weather and be returned to the lawn as nutrients, these lawn cuttings remain on the lawn.

Normally, the lawn cut that is created when mowing with the robotic mower is very short and therefore decomposes quickly and well. However, with longer lawn cuttings, this can lead to matting of the lawn and negatively affect the aeration of the lawn. Lawn clippings that are too large can also promote the spread of various lawn diseases.

So when you use the spiral cut, you should be careful not to “abuse” it by mowing as little as possible, so that this problem does not arise.

Another problem could be the emerging “crop circles”. These are not visible on every lawn and not everyone notices them. Some Automower-owners however already reported, by spiral mowing on their lawn, “crop circle” patterns can be seen. Ultimately, the only way to find out whether this is a problem for you and whether it bothers you is to test it out. However, it does not seem to be a very common problem.

Which Robotic Mowers Use the Spiral Cut?

The following robotic mowers are equipped with the spiral cut function and can either use it automatically or you can start it manually

• AMBROGIO L200 Carbon Blackline
• AMBROGIO L250i Elite GPS
• AMBROGIO L350i Elite GPS
• AMBROGIO L400
• AMBROGIO L85 Elite
• HUSQVARNA Automower 305
• HUSQVARNA Automower 310
• HUSQVARNA Automower 315
• HUSQVARNA Automower 315X
• HUSQVARNA Automower 430X
• HUSQVARNA Automower 430XH
• HUSQVARNA Automower 435X AWD
• HUSQVARNA Automower 450X
• HUSQVARNA Automower 450XH
• HUSQVARNA Automower 535 AWD
• HUSQVARNA Automower 550
• HUSQVARNA Automower 550H

I make no claim to completeness.

Related Questions

Why does the Automower go into spiral cutting mode so often? If the Automower goes into the spiral cut mode too often (e.g. 10 times a day or more), the lawn is probably being mowed too infrequently. The intervals between the mowing passes should be reduced. Spiral mode may also be activated frequently for particularly robust lawn types. This is not a problem, but can be remedied by setting the spiral cut intensity to low.

High and low intensity in spiral cutting: what does this mean? If the settings for the intensity of the spiral cut are also high, this means that spiral cutting is used particularly frequently. If the settings are low, it is used less frequently.