What Plants Need: Air
Nothing Beats Fresh Air
It’s one of those things you don’t think much about, unless you don’t have it. We all know that good air quality is aided substantially by the presence of an abundance of plants to take up carbon dioxide and produce oxygen. Here are a few interesting facts about air and plants:
- NASA has shown that a variety of houseplants can remove ammonia, formaldehyde, benzene, trichloroethylene, xylene and toluene from the air. Cleaning pollutants from the air using plants is called phytoremediation.
- Earth’s atmosphere is 21% oxygen, which is produced by microbes called cyanobacteria, or blue-green algae. These micro organisms, in the form of “chloroplasts,” perform photosynthesis in all plants.
- Earth’s atmosphere is 0.039% carbon dioxide (CO2), the element that we exhale and plants require to create glucose through photosynthesis. Plants do quite well with that concentration, but scientists and hobbyists alike have experimented to see if greater concentrations of CO2 have an effect on plant growth. It seems that the jury is still out: when one element changes, adjustments up or down must be made elsewhere and we don’t know the formulas.
Air For Life
To review elementary life science, photosynthesis happens in the leaves of plants. The green color we see is the active blue-green algae doing their thing. They remove CO2 from the air and H2O from the soil, and blend them in the presence of sunlight. (Did I mention that this only happens in the daytime?) The plant keeps the carbon, the hydrogen and some of the oxygen to make glucose (sugar), and lets go of some of the oxygen. The glucose is the plant’s food, some is used immediately, some is stored, some is passed on to it’s progeny when seeds are made.
Air For Growth
The other air necessity for plants is good air circulation. This is a more passive need than the air they metabolize, but vital nonetheless. Plants that are crowded are at risk from several fronts. Tight spacing hinders evaporation. A constantly damp location harbors plant diseases such as powdery mildew and black spot. Pests like aphids, scale and slugs thrive in these damp, calm environments. Also, without flexing in the occasional breeze, branches and stems do not develop proper rigidity, but remain weak.
To promote good air circulation, first plant according to recommended spacing. Keep in mind the locations of buildings, walls and other causes of stagnate air, and leave ample space in those areas. Areas such as and vegetable beds should be kept weed free to allow for maximum air flow. Established shrubs and trees may require occasional thinning to allow air circulation within the canopy of the individual plant. If diseases or pests are on the rise, always consider and eliminate poor air circulation as a possible root cause.
What’s In A Plant
Depending on the point of view, plants may be considered as simple air filters, a role that they fill quite admirably. Another thought is that these simple air filters, including lettuce, tomatoes, oranges and the rest, contain traces of everything they have absorbed from the atmosphere. With these things in mind, you may consider the best placement of landscape and edible plants in your yard. You may be wise to think about this as you go grocery shopping too.
More in the “What Plants Need” series:
