I’m building my garden in the back corner of my property, but as I was discussing my garden with a friend he mentioned that he has a septic tank and that made gardening a little more difficult. It’s not something I have to worry about, but it is definitely something I’d be concerned about if I lived in a home that does use a septic tank. I remember that my sister had a septic system on her property some years back and she had a flower garden.
So, can you plant a garden over a septic field? You can, but shouldn’t plant a garden over a septic field, even if you are careful about what you’re planting and you know the risks involved with possible contamination and damage to the septic system.
Can you build a garden over a leach drain field, and should you are the beginnings of two very different questions. Can you? Yes. Should you? No. I know, these septic fields are quite tempting because they are big, flat, sun-soaked spaces that look so welcoming to a garden, but you’ll want to avoid the temptation.
Gardens can grow well over septic fields for the same reason they grow well when manure is mixed into your soil – there are tons of nutrients for your plants to absorb! It’s just not advised because there are just too many risks involved.
Vegetable gardens and flower gardens are different though. While just about any of your plants will thrive over a septic field, you’ll want to be careful about which plants you choose to put there. While I don’t mind a little manure in my garden soil, I’m not near as interested in having bacteria contaminates splash all over my food.
Personally, I’ll stick to flower gardens, or preferably, grass over any septic tank I come across. For me, it’s a matter of not really knowing if the septic system is properly working or if I’ve caused damage to it and I don’t want to take the health risk or the risk of damaging the septic system. A good, working septic system probably isn’t going to end up contaminating the soil, but I don’t personally know how to check and make sure of that and I’ve been informed it’s not easy.
If you’re dead set on planting a vegetable garden, and your only choice is over a septic field, you’re going to want to reconsider or proceed at your own risk. If you must, try not to plant root vegetables directly over drainage lines, if there is contamination the root vegetables will soak it right up and that’s not going to be good for you. Avoid planting leafy vegetables (they’re more difficult to clean) and splashing water will carry contaminates onto your vegetables. Use cages and trellises for vine crops like tomatoes and cucumbers to keep them off the ground and avoid as much of the splashing as possible from water striking the soil. Make sure you wash your crops before eating them (as with any garden produce, no matter where it comes). Avoid using raised garden beds, they make it difficult for your septic system to drain properly because they retain too much water in the soil. Finally, wear gloves when gardening over a septic field so that you do avoid as much direct contact with possible contaminants. Oh, and once again – just don’t plant your garden on a septic field. It’s not safe for you or the septic system.
As it turns out, planting over the septic field really isn’t a big problem for most of your garden vegetables (other than root vegetables), but it could become a problem for your septic system and could lead to contaminated food. Most landscapers and gardeners will tell you that grass is your best bet and you should avoid gardens no matter how tempting they are in this field.
You should also consider keeping a few other things off your septic field as well. Driving on the field with cars, trucks, or other heavy equipment will damage the drainage lines. Some of the drainage lines are relatively close to the surface and even smaller machines like 4-wheelers and dirt bikes and riding mowers could cause an issue and break the drainage lines due to the weight of the machine. You also should NOT do any hardscaping or raised gardens over the septic field.
Overall, you run a lot of risks if you plant your garden over a septic field both to your health if there is any soil contamination and to your wallet, if your septic system is harmed by your gardening (regular foot traffic, raised garden beds, digging, tilling, irrigation, regular watering – all of these can damage a septic system).
How close can you plant a garden to a septic field?
So, I’ve convinced you to keep your garden off your septic field and now you want to know how close you can get to the edge without falling off, eh? The safest bet is to keep your fruit and vegetable plants at least 10 feet from the outer perimeter septic system or leach field so that you don’t run the high risk of contamination and you avoid damage to the septic system itself.
Can I place a raised bed over a septic field?
Placing a raised garden bed over a septic field could spell disaster! Don’t do it! While this may help prevent your plants from a higher risk of contamination because it effectively moves the plants and roots further from the septic system, it will cause issues to the septic system itself. Septic systems and leach fields need to allow moisture to get out. Placing a raised garden bed on top of your septic system or leach field prevents the moisture from getting out and can damage the system. Again, don’t do it. Avoid placing anything over your septic system that would inhibit the evaporation of moisture – that includes any kind of hardscapes from pathways and pavers to firepits to raised garden beds.