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There are many benefits of houseplants that are scientifically backed, but there are some places where fact may have been a bit over exaggerated to the extent that it has become fiction. Or, there are some care tips and tricks which are really old wives tales which may have been falsely passed down to you. Whatever the case, we are here to help you set the record straight and bust some of these myths once and for all.
Myth 1: All Indoor Plants Purify the Air Significantly:
While it's true that plants can absorb certain chemicals like formaldehyde and benzene, the scale at which typical houseplants purify air is much smaller than often believed. The original study that fueled this myth was conducted by NASA in a highly controlled environment, not a typical home setting. In reality, you would need a very large number of plants in a small space to significantly purify the air.
The study often cited in discussions about houseplants purifying the air is a research project conducted by NASA in the late 1980s. This study was led by Dr. B.C. Wolverton and aimed to explore ways to purify the air in space stations. The findings were published in a report titled "Interior Landscape Plants for Indoor Air Pollution Abatement."
Key Points of the NASA Study:
Objective: The primary goal was to investigate the potential of common houseplants to remove volatile organic compounds (VOCs) like benzene, trichloroethylene, and formaldehyde from the air. These compounds are known pollutants commonly found in indoor environments, originating from products like paints, varnishes, and cleaning supplies.
Methodology: The study used a sealed chamber in controlled conditions, where various plants were exposed to specific chemicals. The researchers then measured the concentrations of these chemicals in the air over time to determine the rate at which plants were able to absorb them.
Findings: The results showed that certain plants were indeed capable of removing VOCs from the air. The study highlighted that plant leaves, roots, and associated soil microbes play a role in reducing airborne pollutants.
Popularized Concept: This study popularized the concept that houseplants could improve indoor air quality by acting as natural air purifiers. It led to widespread belief in the effectiveness of indoor plants in reducing indoor air pollution in typical home and office settings.
However, it's important to note a few caveats:
- Controlled Environment: The NASA study was conducted in a controlled, sealed environment, which is not representative of the typical home or office.
- Scale of Effect: In real-world conditions, the number of plants required to significantly purify the air in a room would be impractically large.
- Air Exchange Rate: In typical buildings, air exchange with the outside environment greatly diminishes the potential impact of plants on indoor air quality compared to the sealed conditions of the study.
Myth 2: Plants Like to Be Watered on a Strict Schedule:
Each plant has unique watering needs, and these needs can change with the seasons, the plant's growth stage, and the indoor environment. Overwatering can be just as harmful as under-watering. It's better to learn the specific needs of each plant and check the soil moisture regularly.
What could impact a watering schedule?
Type of Plant:
Different plants have varying water needs. Some plants, like succulents and cacti, naturally require less frequent watering, while others like ferns and tropical plants may need more consistent moisture.
The type of soil affects how quickly it dries out. Sandy soils drain more quickly than clay soils, thus requiring more frequent watering. Soil that contains more organic matter retains water longer.
Pot Size and Type:
The size and material of the pot can influence soil moisture. Larger pots hold more soil and, therefore, retain moisture longer, while smaller pots dry out faster. Porous materials like terracotta allow soil to dry more quickly than plastic or glazed ceramic pots.
The amount of light, temperature, and humidity in a plant's environment will affect its water needs. Plants in brighter light or higher temperatures may need more frequent watering. High humidity can slow down soil drying, reducing the need for frequent watering.
Plants typically need more water during their active growing season (usually spring and summer) and less during dormant periods (fall and winter). Changes in daylight and indoor heating can also affect how quickly soil dries out. You can help account for lighting changes by introducing a grow light into your setup. We recommend the Grove™ Grow Bar Light, the perfect solution to add into setups, perfectly designed to fit under cabinets or into the tightest of corners.
Plant Size and Growth Stage:
Larger plants or those in a rapid growth phase may require more water. As plants grow, their water needs can increase.
Good air circulation helps soil dry more evenly but can also lead to quicker drying of the soil, especially in conditions with low humidity.
The type of water used can affect plant health. Some plants are sensitive to chemicals in tap water, like chlorine or fluoride, and may require filtered or distilled water.
To manage these factors effectively:
- Regularly check the soil moisture at various depths.
- Adjust watering based on the specific needs of the plant and changes in the environment.
- Be flexible and responsive to the plant's signals, such as changes in leaf color or turgidity.
Myth 3: More Fertilizer Leads to Faster Growth:
Just like with water, more is not always better when it comes to fertilizer. Over-fertilizing can harm a plant, leading to nutrient burn or imbalanced soil chemistry. Plants only need a modest amount of fertilizer, and some do well with very little.
Use the Right Fertilizer:
Select a fertilizer that is appropriate for the type of houseplants you have. General-purpose houseplant fertilizers work well for most plants, but some, like orchids, cacti, or succulents, may benefit from specialized formulas. Look for a balanced fertilizer, often labeled with an N-P-K ratio (nitrogen, phosphorus, potassium) like 10-10-10.
Follow the Recommended Dosage:
More is not always better. Using too much fertilizer can damage your plants. Follow the instructions on the fertilizer packaging regarding how much and how often to apply. It's often safer to err on the side of under-fertilizing rather than over-fertilizing.
Fertilize During the Growing Season:
Most houseplants should be fertilized during their active growing period, typically from spring to early fall. During the dormant period (usually in winter), plants require less fertilizer or none at all, as their growth slows down.
Dilute the Fertilizer:
If using liquid fertilizer, dilute it as directed. This is particularly important for indoor plants, as they are more sensitive to strong concentrations of nutrients compared to outdoor plants.
Check the Plant's Condition First:
Don't fertilize a plant that is stressed, such as one that is overly dry, recovering from overwatering, or suffering from disease. The plant should be in good health before you add fertilizer, as the added nutrients can stress a weakened plant further.
Regularly check your plants for signs of nutrient deficiencies or excesses. Yellowing leaves, stunted growth, or leaf burn can indicate problems with your fertilization routine, and adjustments may be needed. Remember, each plant is unique, and what works for one might not work for another, so be observant and adjust your care routine as needed.
Myth 4: Indoor Plants Require Direct Sunlight:
While some plants do require a lot of light, not all plants need direct sunlight. In fact, direct sunlight can harm certain indoor plants. Many houseplants are selected for their ability to thrive in lower light conditions typical of indoor environments.
Understand Your Plant's Light Requirements:
Research the light preferences of each plant you own. Plants are generally categorized into three main groups based on their light needs: low light, medium light, and highlight. Some plants, like certain ferns, thrive in low light, while others, such as succulents, require bright, direct sunlight.
Observe Natural Light Patterns in Your Home:
Pay attention to how sunlight enters your home throughout the day. South-facing windows receive the most light and are great for high-light plants. East or west-facing windows are generally suitable for medium-light plants. North-facing windows or areas farther from windows are better for low-light plants.
Use Artificial Lighting if Necessary:
If you don’t have enough natural light, consider using grow lights. These special lights mimic natural sunlight and can provide the spectrum of light needed for photosynthesis. They are particularly useful in winter months or in rooms without sufficient natural light. We recommend the Aspect™ Hanging Pendant Grow Light from Soltech, which can be installed without any renovation and comes with a timer to assure the perfect conditions all day- and all year- round!
Rotate Plants Regularly:
To ensure even growth, rotate your plants every few weeks. This helps prevent plants from leaning towards the light source and encourages even, balanced growth.
Monitor and Adjust as Needed:
Keep an eye on your plants for signs that they are getting too much or too little light. Signs of too little light include leggy growth, smaller than normal leaves, and a dull, dark green color. Signs of too much light include bleached or scorched leaves. Adjust the plant's position as needed to provide the optimal light conditions.
Myth 5: If a Plant is Drooping, It Always Needs Water:
Drooping can be a sign of various issues, not just lack of water. Overwatering, poor drainage, root rot, or even lack of light can cause plants to droop. It's important to assess other factors like soil moisture and overall plant health before assuming that water is the solution.
What is Root Rot?
When soil is consistently too wet, it deprives plant roots of oxygen, leading to root rot. This condition is caused by fungi that thrive in wet conditions and attack the roots, weakening or killing them. Root rot can spread quickly and is often fatal if not addressed promptly.
What are the Other Dangers of Overwatering?
Reduced Oxygen Supply:
Plant roots need both water and air to thrive. Overwatering fills the air spaces in soil with water, reducing the oxygen available to the roots. This lack of oxygen can stress the plant and hinder its ability to absorb nutrients effectively.
Excessive water can wash away essential nutrients from the soil, depleting the nutrients available to the plant. This leaching effect can lead to nutrient deficiencies, even if the soil was initially well-fertilized.
Fungal Growth and Pests:
Overly moist conditions are ideal for the growth of fungi and the proliferation of pests. Fungus gnats, for example, are attracted to wet soil and can become a nuisance. Fungal diseases, like mildew and mold, can also take hold in damp environments.
Stunted Growth and Yellowing Leaves:
Overwatered plants often exhibit stunted growth, yellowing leaves, and wilting. While wilting is typically associated with under-watering, it can also occur when roots are damaged by too much water and cannot function properly.
When plants absorb more water than they can transpire, it can lead to a condition called oedema. This is where the cells in the leaves and stems burst, causing blisters or water-soaked spots. Over time, these spots can turn into corky, brown scars.
Prevention and Management:
Check Soil Moisture: Before watering, check the soil moisture. This can be done by feeling the soil a few inches below the surface or using a moisture meter.
Proper Drainage: Ensure that pots have drainage holes and use well-draining soil to prevent water from accumulating at the roots.
Watering Schedule: Adjust watering according to the plant’s needs, the season, and environmental conditions. Some plants require more water in growing seasons and less in dormant periods.
Observe Plant Signals: Look for signs like leaf color and soil condition to guide watering. Not all drooping or yellow leaves indicate a need for water.
There’s no shame in realizing you have been believing a myth! If you learned something from this article, then that is step one to making sure you are perfecting your plant parenting skills. Always do your research, closely and carefully. That is the most important skill in houseplant care.