Despite the fact that septic tanks normally have their operations beneath the ground, starting a garden on top of it can be dangerous to your health and your waste handling arrangements. Homes located in rural areas can’t access municipal sewer systems and depend on individual septic tanks to discharge waste material out to discompose and safely dissolve into soil.
Most of these systems have a holding tank underground that is linked to draining systems in some way. As water goes through the tank, solids will settle down and water waste flows down the drainage field, a place where soil microbes will clean out harmful bacteria before it gets to ground water. Normally, the 18 to 36 inch wide lines can go up to one hundred feet long. The number of lines your field has depends on the number of individuals in your home.
Advantages and Disadvantages of Plants
The most common advantage of plants is the fact that they help the drain field function. They do so through stabilizing the top soil to prevent soil erosion by eliminating excess moisture. One setback that can arise from that is the fact that some plants can grow too deep, damaging drain lines. Even basic plants like vegetables can grow long roots enough to affect shallow septic systems.
As much as increasing the depth of soil seems logical, it can affect leach field landscaping in so many ways. It reduces the amount of oxygen needed to break waste discharge, as a result, evaporation is cut drastically. Normal gardening tasks like fertilizing and tilling can affect draining fields.
Watering a raised bed that has been planted by moisture loving plants can significantly affect the water retention capacity of that drain field. It is important to note that plants that work well with drainage fields have mat-forming, shallow roots that need little attention or water.
Food Safety Concerns
When you plant consumables like fruits and vegetables on top of a septic tank, you risk getting a harvest infested with dangerous bacteria. Low growing greens and root vegetables are the highest risk of getting contaminated with human pathogens like coli, something that could easily get consumed. If you have a garden near a septic tank, it is recommended that you wash them thoroughly before consuming them. For safety measures, wear protective gear like garden gloves whenever you’re working in any plantation over or near a septic field.
Always Plan Before Planting
Before you initiate your plan of having a raised bed, it is important to locate exactly where your septic field is buried in your home space. This should be an easy step because septic field layouts are contained in closing documents or home inspections catalogue when you bought your home.
According to Indiana Clean Water, raised beds or any form of vegetable garden should be at least twenty feet away from the septic field. If that isn’t possible, then it should be at least on the far end of the sept tank where it stays clear of waste discharge. Additionally, plants that have shrubs, deeps roots or trees should always be planted more than twenty feet away from the drainage field.
Safe Plants to Grow On Septic Tanks
There are certain shrubs and trees that can be harmful when when planted near drain fields. There are, however, certain plants that are safe to grow on septic tanks. Being paranoid over the potential harm to septic tanks that can be caused by roots from plants can lead to total abstinence from the practice. Planting the right type of vegetation on septic tank is permissible and advisable.
Growing the right plants on septic systems can prevent soil erosion through eliminating excessive moisture from the area. It is good to grow bluegrass or any other type of mulch over septic tank fields. Growing weeds over septic field is also a preferable option. It is better than leaving the ground bare. Jewelweed (Impatiens capensis) and creeping Charlie plants will produce and multiply at a faster rate, covering more septic space.
According to Water Technology Engineering, grasses and perennials are the best option to grow around drains fields and septic tanks. This is because they have a very shallow root system that cannot affect the underground septic system averting potential damage. Similarly, non woody and small ground covers are also a good option.
There are many examples of such plants so it is important to explore your options carefully. The best way to do so is through considering the growth options. If you stay in a sunny area, you should opt for recommended perennials that work well in hot and sunny regions.
If your septic field doesn’t get enough sunlight, you should opt for shade garden plants. The soil condition around the septic tank can sometimes be saltier or wetter than average, the best way to handle such a scenario is adding soil on top of leach field. It is good to cover both base areas with materials like hollyhocks, bee palm or wild violets that work well with salty and wet grounds.
Herbivorous animals like deer will not want to consume plants growing on top of septic systems, so if your area is infested with crop eating animals, then you should go for these crops that they can’t consume. It will save your garden in many ways. It is not recommended to grow crops you might want to consume on top of septic fields because they might be contaminated by harmful bacteria.
If you must grow a tree, then the shallow-rooted types are the best option to go for. Shallow roots mean they cannot affect the septic tank system in any way. These type of crops include:
- Eastern redbud trees
- Dogwood tress
- Japanese maple trees
- Azalea shrubs
- Cherry trees
Plants Not To Grow Over Septic Systems
Don’t plant fast growing and large trees. One of the worst crops to grow over a septic system are shrubs and trees that have water-hungry root systems. This means they don’t care about the water systems they tap into, even pipes in the septic tank could be an option. They can damage your septic system in many ways.
Avoiding these plants does not mean everything has been taken care of. There is still danger initiated by any mature, large trees growing less than 20 feet away from your septic tank. The basic guidelines advise that such kind of trees need to be more than 50 feet away. If that doesn’t happen, then your septic system is at high risk of being damaged.
The design of a septic tank has a role in determining the kind of crops that can be sustained around it. It operates in such a way that solids sink to the bottom and scum comes up to the top. This means toxic substances with water are more exposed to the crops growing around the septic space. It is recommended to grow plants that will not in anyway affect the septic system in your home.