Growing houseplants indoors can be challenging, especially in rooms without much natural light. While sunlight provides the perfect balance of wavelengths for plant growth and blooming, artificial light is an excellent alternative for nurturing indoor plants. With the right approach, even low-light foliage plants like pothos and peace lilies can thrive in windowless spaces. This guide will teach you how to use artificial lighting to help your houseplants flourish, saving you time and money.
Understanding Plant Light Needs
Plants require specific types of light to grow and thrive. To successfully grow houseplants using artificial light, here’s what you need to know about their basic light requirements.
Blue Wavelength Light
Blue light is essential for foliage growth. It promotes the development of strong, healthy leaves and stems. This type of light is particularly important during the vegetative stage of a plant’s growth cycle. Blue light triggers chlorophyll production for photosynthesis, giving plants the energy to grow and maintain their structure. This wavelength keeps plants compact and bushy.
Red Wavelength Light
Red light supports flowering and fruiting. It stimulates the production of flowers and fruits in plants that can bloom indoors. This wavelength becomes more important as plants mature and enter their reproductive phase. Red light influences germination rates and root development, helping the progression from vegetative growth to blooming.
Green Wavelength Light
Interestingly, plants have little use for green wavelengths. They reflect most green light, which is why leaves appear green to the human eye. This reflection is part of the plant’s natural light management system. Despite this, green light penetrates deeper into the leaf than other wavelengths, potentially influencing plant structure and contributing to some growth processes.
Types of Artificial Lights for Houseplants
Choosing the right artificial light source is crucial for the success of indoor plants. There are several options available, each with pros and cons. Here’s an overview of the most common types of artificial lights used for growing houseplants.
Fluorescent Lights
Fluorescent lights are a popular and economical choice for houseplants. They come in two main forms:
- Tubes: These are ideal for larger plant setups or growing shelves.
- Compact Fluorescent Bulbs (CFLs): These screw into regular lamp sockets, making them versatile for various fixtures.
Fluorescent lights are cool-running, allowing you to place them close to plant foliage without causing heat damage. They’re particularly high in blue wavelengths, which is excellent for foliage growth. For a balanced light spectrum, look for “full-spectrum” fluorescents or use a mix of “cool” and “warm” bulbs. When in doubt, “cool white” products are a safe bet as they contain a full spectrum of wavelengths.
Fluorescent lights come in a range of sizes and intensities, and you can customize them to fit any indoor gardening arrangement.
Incandescent Lights
Incandescent bulbs emit more heat than other options. Place them farther from plants to avoid leaf burn. They produce more red wavelengths, making them useful for supplementing fluorescent light to encourage blooming. If you combine incandescent with fluorescent lights, aim for a ratio of about one-third incandescent to two-thirds fluorescent by wattage.
While they’re not as efficient as other lighting types, incandescent bulbs are a low-cost way to add supplemental light where needed, particularly for plants that are farther from the primary light sources.
LED Lights
LED lights are becoming increasingly popular for indoor plants. They offer several advantages:
- Energy efficiency
- Low heat emissions
- Customizable light spectrums
Choose LED lights that produce the necessary blue and red wavelengths for plants. Some horticultural LED grow lights emit only the wavelengths most utilized by plants, making them an excellent choice for serious indoor gardeners. LEDs come in a variety of shapes, sizes, and configurations, including panels and strips, offering flexible options for different growing setups.
Halogen Lights
Halogen lights can provide full-spectrum light, but, like incandescent bulbs, they generate a lot of heat. They’re less energy-efficient than fluorescents or LEDs, making them a less common choice for houseplant lighting, but they are suitable for specific scenarios where you need high-intensity light for short durations.
Horticultural Grow Lights
These specialized lights typically come in tubes for fluorescent fixtures. They contain the full spectrum of wavelengths needed for blooming plants such as African violets. While some gardeners find them useful for starting seeds or propagating hybrids, others achieve similar results with simple full-spectrum fluorescents. Grow lights are often designed to be more attractive and fit seamlessly into living spaces without intruding on the decor.
Setting up Artificial Lighting for Houseplants
Creating an effective artificial lighting setup for houseplants doesn’t have to be complicated. Here’s a simple approach for rooms with low natural light:
- Choose a standing lamp with three bulb sockets, preferably with adjustable or gooseneck fixtures.
- Install one incandescent bulb and two compact fluorescent bulbs, using the highest wattage that’s safe for the fixture.
- Direct the lights toward the plant table or shelf.
- If you can individually adjust the fixtures, position the fluorescent bulbs closer to the plants than the incandescent bulbs to avoid heat damage.
- Place a mirror or reflective surface beneath the plants to bounce light back to the foliage.
- Connect the setup to a timer set for 16 hours of light per day.
This combination provides a good balance of light wavelengths, and you can easily adjust it to suit different plant needs. Reflective materials maximize the efficiency of your lighting system.
Positioning Artificial Lights for Optimal Growth
Proper positioning of artificial lights makes sure that your plants receive enough light. The distance between the light source and the plant can significantly impact growth and health.
Distance From Plants
As a general rule, position fluorescent and LED lights about 6–12 inches away from plant foliage. For taller plants, use multiple light sources at different heights for even coverage. Minimizing shadows and providing full-spectrum exposure helps plants develop evenly.
Duration of Lighting
Most houseplants benefit from 14–16 hours of artificial light per day. A timer can help maintain a consistent light schedule, which is important for plant health and growth cycles. Simulate a natural day and night cycle for your plants to prevent stress and maintain healthy photosynthetic activity.
Adjusting for Plant Height
As plants grow taller, adjust the height of the lights accordingly so that all parts of the plant receive adequate light, promoting even growth and preventing stretching or leaning. Keep an eye on the plant’s development so you can adjust as needed, leading to healthier, more vibrant plants.
Choosing the Right Plants for Artificial Light
While many plants can adapt to artificial light, some are particularly well-suited to these conditions. Here are some excellent choices for growing under artificial light:
- Snake Plant (Sansevieria): Hardy and low-maintenance
- Pothos: Adaptable with air-purifying qualities
- ZZ Plant: Tough character and glossy leaves
- Chinese Evergreen: Decorative foliage and grows well in low light
- Peace Lily: Enjoys indirect light and high humidity
- Spider Plant: Famous for its air-cleaning capacity and style
- Philodendron: Has numerous varieties and is easy to care for
- Dracaena: Striking leaves that are available in many forms
- Aglaonema: Resilient with colorful foliage
- English Ivy: Elegant and versatile with many varieties
These plants are adaptable and can thrive in lower light conditions, making them ideal candidates for artificial light setups. One or more plants on this list will suit your preferences and environmental conditions.
Monitoring Plant Health Under Artificial Light
Watch your plant health closely when you’re using artificial light. Here are some signs to watch for.
Signs of Not Enough Light
When these symptoms occur, try increasing the light intensity, extending the duration, or repositioning the lights to improve overall exposure:
- Leggy or stretched growth
- Pale or yellowing leaves
- Slow growth or no new growth
- Leaf drop
Signs of Too Much Light
Reducing light exposure provides relief from stress and helps restore plant vitality. If you notice these signs, adjust the light intensity or duration accordingly:
- Scorched or brown leaf tips
- Faded or bleached leaves
- Wilting despite adequate watering
Supplementing Natural Light with Artificial Light
In many cases, artificial light supplements rather than replaces natural light. This can be particularly useful during winter or in rooms with limited window access. When supplementing with natural light:
- Position plants near windows when possible.
- Use artificial lights to extend the “daylight” hours.
- Adjust artificial light intensity and duration based on natural light availability.
This approach can help maintain healthy plant growth year-round, regardless of seasonal changes in natural light.
