Removing Metals From Your Soil With Hyperaccumulating Plants
A beautifully designed lawn can improve the aesthetics of your home and bring a sense of peace and harmony to your surroundings. However, if you live in an area with high metal concentrations in the soil, you may have difficulty growing plants. It is still possible to have a beautiful landscape by choosing plants that remove metals from the environment.
The Source of Metals In Your Soil
Some metals, such as arsenic, are always found in trace amounts in the soil and are not harmful at low levels. However, metals can accumulate to dangerously high levels when they find their way into your soil by moving through ground water supplies from a pollutant source.
Sometimes, metals can also be inadvertently added to your soil if you use compost that contains coal ashes, manure, or processed feeds. If you buy compost through a large manufacturer rather than from a local source, it is also possible for contaminants such as leaking batteries to end up in the compost due to improper sorting.
For these reasons, it is important to have your soil tested for heavy metals, even if you may not suspect a problem. This is especially crucial to your health if you are growing vegetables. Once inside the body, heavy metals will accumulate and cannot be easily eliminated. In high amounts, metals like arsenic and mercury can even lead to serious health problems.
Removing Metals with Hyperaccumulating Plants
With careful landscape design, many metals can be removed from the soil. Certain plant species are known to be hyperaccumulators. These plants are able to grow in soils that contain very high concentrations of metals. In a process called phytoextraction, hyperaccumulating plants absorb the metals through their roots and store them inside their leaves and roots. If you are living on or near a site that has been contaminated and your soil test has shown high levels of metals, hyperaccumulating plants will be able to reduce the toxic level of the environment.
There are over 500 hyperaccumulating plants, so you should be able to find a few that can effectively address the type of metal in your soil. The following metals can be removed with these plants:
- Arsenic – Brake Fern, Pteris vittata
- Cadmium and Zinc – Alpine Pennycress, Thlaspi caerulescen. Be aware that this plant is only effective in moderately contaminated soils and will not be able to thrive or perform effectively in highly contaminated soils.
- Chromium – Sunflower, Helianthus annuus
- Copper – Creosote Bush, Larrea tridentata
- Lead – Cabbage (Just don't eat the cabbage or you'll be transferring all that lead from your soil to your body)
- Mercury – Rapeseed Plant, Brassica napus
- Selenium – Indian Mustard, Brassica juncea. The genetically modified version of Indian mustard is able to accumulate 2-4 times the amount of selenium as the wild type.
Work with a landscaping artist to incorporate the plants you need for contaminant removal into your overall landscape design to maintain the aesthetics of your yard. You can also take advantage of some plants, such as Indian mustard, that are able to remove more than one type of metal from your soil.
It is possible to restore the health of your soil from metal contamination. With careful selection of plants and landscape design you can even enjoy growing and eating vegetables from your garden. Contact a landscape contractor like JK Landscape Construction for more information.