I need a lawn mower that can handle rocks and tall thistle bushes. I go through a lawn mower a year it seems. 90% of our ground is granite with a shallow ground covering. Any suggestions?
You've basically described what I have in my lawn and fields, except that I have blackberry instead of thistle.
What I use:
- For my lawn I use a self-propelled walk-behind Toro purchased from a big box store several years ago. The blade is in horrible shape (I should replace it), but I sharpen it with an angle grinder a few times a year and it keeps doing the job. This machine has been thoroughly abused: I knock down heavy weeds (small brush) with it, it has had numerous encounters with rocks, uneven ground, etc.
- Another tool that is very useful is a scythe. I use this in areas where the mower can't go, or there are just too many rocks and the ground is too uneven for the mower. Just be careful to mow high with the scythe or you'll ruin the blade on the rocks.
- I've used a string trimmer ("weed whacker") in the past, but sharp rocks tend to eat up string really fast, and they don't work well on thick, woody weeds (e.g. blackberry). I've seen some that have a blade instead of a string, but hitting rocks with a blade seems
- At a larger scale, I recently got a field mower attachment for my tractor. This is used on a couple acres of horse pasture. (Yes, up until this summer, I used the little Toro to knock down brambles in the pastures.) It easily handles small brush, and the blades will give way if they hit a rock. (Though I have already had to replace a shear pin when it hit a rock that was too big.)
- I have not used them, but I know people that have the DR brush mowers as mentioned in a comment on the question by @DA. You may want to consider something like this.
For any solution, it's helpful to:
- Remove as many rocks as possible from the area to be mowed. This avoids damaging equipment, and potentially throwing rocks that could injure people or damage property (e.g. your living room window).
- Mow high. Set the blades high to avoid hitting shallow ledge outcroppings that you simply cannot remove.
- Lower your expectations. With the conditions you've described, you're not going to have a golf course lawn. If that's what you want, you're going to need to have many tons of screened topsoil trucked in to cover the rock.
- Consider alternative landscaping. Some areas just don't need to be mowed. You may be better off deciding against a lawn in a problem area.
- Learn how to maintain the equipment yourself. At the very least, an investment in a vise and angle grinder, and time to learn how to sharpen a mower blade can pay off over the course of a summer.
I mow 3 acres using a DR walk behind string trimmer. It takes about 2.5 hours. Here is what I tried:
A lawn mower at the highest setting: The blades will deteriorate real quick. The mowing deck will keep breaking.
A DR tow behind brush mower. It does work, the lawn does not look pretty because it is a rough mower. Also because the grass is tall, it grows back real quick. One time, I found 1.5 foot weeds ONE WEEK after I mowed. If it gets stuck, it is a heavy machine and it is a pain to get it out. It is also a big pain because you have two engines to worry about. That of the lawn mower which is barely enough to pull the brush mower and that of the brush mower itself. If you have an ATV, this may be an ok option. It also uses a lot of gas. I would say about 2-3 gallons.
The string trimmer works pretty well. It is fairly consistent and straightforward especially if you keep it mowed. Every 2 weeks is ideal. Every 3 weeks is pushing it. I look at it as a form of exercise and it is very easy to get started. By the time you figure the amount of time to set up the tow behind and add gas and tune both engines, this turns out to be the faster alternative (in my case). I go through about 1 set of strings every time I mow. It is also helpful to keep a belt handy just in case. I would say on average it costs about $5 in belts and strings and gas (less than a gallon).
Call a landscaper and have them fix it. They can remove rocks or bury them with dirt and leave you with something you can maintain (you could do this yourself, but considering your request for advice, I doubt you are able to tackle something like that (and they have heavy equipment)). Fix it once and it will save you months of frustration on a yearly basis, a very sound investment in time and sanity.