Here we discuss what makes a good (and bad) manual hollow tine aerator.
It’s nearly all about the tines, these are the part that are pushed into the ground and extract a core of soil.
Tine Design- There are 2 main types defined by how the core is ejected; ‘top eject’ the core comes out the top of the tine. The core has to travel the full length of the tine for these and therefore there is a greater chance of blockages. Side eject, these eject the core out of the side of the tine, the core is much less likely to get clogged.
Top eject models can still work but they need the internal chamber to widen as the core passes upwards to avoid clogging.
A side eject with a widening internal chamber.. now you’re talking!!! The only problem is making a tine with a widening internal diameter means starting with a solid metal bar and machining out the internal profile which is expensive.
Tine Material - The contact area of the tines is really small and that surface area has the full weight of you stomping on it! It will hit stones under your lawn so it needs to be an extremely hard material to stand up to the task. Normal steel isn’t hard enough, stainless steel is better but nowhere near the hardness of hardened steel.
The ideal tine is a side eject design made from hardened steel with an internal chamber that widens. The problem with this though is it’s extremely expensive to manufacture these.
The Lawn-Kit aerator solves this problem by using a composite tine. The tip is hardened steel and it has an internal profile that widens. These are made to the exact same spec as the tines used in the mechanical aerators on top golf courses. The tips are then bonded into a mild steel side eject tube.
What else to look for? Rubber grips for comfort and a well made body.
Price- be wary of the aerators in the sub £60 price category, these are likely to come from China and be manufactured as cheaply as possible, typically costing under $10 a unit. Look at the tines carefully, they are highly likely to be prone to clogging. You can easily spend £50 on an aerator that doesn’t work and leave it in your shed gathering dust.
Also look at online videos of these in use, do any of them show you an aerator repeatedly extracted cores without any clogs? There’s a reason for that!