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Light for House Plants: Everything you Need to Know

Keeping indoor plants and seeds thriving can be challenging when you fail to provide a reliable lighting source, especially during scarce sunlight.

Generally, there are three types of house plants based on light needs; low, medium, and high light-loving. Other than sunlight (direct or diffused), artificial lighting (LED, Fluorescent, HID, or other) in varying intensity, spectrum, and duration, also helps healthy indoor plant growth.

Follow this guide if you are unsure how much lighting your indoor plant demands and where to shop them.

What are the Light Requirements for Indoor Plants?

All plants require light for photosynthesis, converting sunlight, oxygen, and water into carbohydrates or energy.

Like humans with varying appetites, plants boast changing light requirements. Here are four different factors you should know about.

1. Light Intensity

In simple terms, light intensity describes brightness (the amount of light energy that falls on a surface per unit area).

If you are wondering, the intensity or brightness determines how much light reaches or is available to the plant.

houseplant outsides
Most potted house plants cannot tolerate bright direct light.

In fact, it becomes a crucial factor because too bright or dim lighting may not have a desirable effect on the plants.

It is measured in PPF (photosynthetic photon flux), lux, foot candles, or lumens to give you a better idea.

Lux (sq. meter)PPFFoot Candles (sq. feet)Lumens
1002.3 umol/s/m29.291,000

For example, bright sunlight (over 10,000 lux) can burn sensitive plants, while a dimly lit room (20-30 lux) will be insufficient for sun-loving plants.

2. Light Distance

Yes, distance from the light source can affect a plant’s growth because the intensity decreases as light travels away from its inception.

If the light is too weak, the plant may not be able to photosynthesize enough, and too intense light will burn the plant.

Remember these few tips when placing artificial light close to your plant.

Seedlings4-6 inches (100-152 mm)
Succulents6-12 (152-304 mm)
Vegetables12-14 (304-355 mm)
Flowering plants6-12 (152-304 mm)

Moreover, you must monitor the plant’s condition equally to adjust the light distance to ensure optimal growth.

3. Light Duration

Also known as photoperiod, the light duration determines how long a plant is exposed to light to attain desirable results.

It may be essential for germination, flowering, and fruiting, which require various duration of light.

Some plants require more exposure to light, 8 hours or more, than others, for example, flowers and vegetables.

Most indoor plants that bear foliage are called short-day or day-neutral plants that do well in short-light duration.

Check out this table to learn more.

FactorDuration per day
Seedlings16-18 hours
Succulents6-8 hours
Vegetables12-14 hours
Flowering plants14-16 hours

4. Light Spectrum

Often referred to as light color, the light spectrum is vital for any plant growth.

Different wavelengths (measured in nm) of light affect plant growth differently, and certain wavelengths are necessary for specific stages of development.

  • Most plants grow well in full-spectrum lighting, a combination of blue and red (400-700nm) with smaller amounts of green, yellow, and Infrared.
  • Blue light (400 nm) helps with the vegetative growth and development of leaves.
  • Red light (700 nm) helps with flowering and fruiting
  • Far-red light (>700 nm) especially helps with germination.

However, you need not be too picky about the light spectrum as much as the duration, distance, and intensity.

Indoor Plants Based on Light Requirement

Indoor plants require as much light as any outdoor plant, but the light intensity and duration will vary.

Remember, indoor plants are attuned to living in the existing light conditions, where their growth will depend on the light available.

Before getting a plant or starting seeds, determine your space’s quality and hours of natural light. Then choose plants with light requirements that match your indoor environment.

That said, each indoor plant has a light requirement sufficient to observe healthy, even growth and is classified into three types.

Low LightMedium LightBright Light
Enjoy shade with light bright enough to read a newspaperNeed well-lit areas but despisee bright or direct sunlight Thrive under bright light, sometimes even direct sunlight
Chinese evergreenGrape ivyCacti and succulents
Cast iron plant Elephant ear (Alocasia)Citrus such as calamondin orange, kumquat, Meyer lemon
Ponytail palmNorfolk Island pine Hibiscus
Parlor palm Asparagus fernCulinary herbs, basil, thyme
Dumb caneJade plantTi plant
DracaenaRubber plantOrchid cactus
English ivyFiddleleaf figGardenia
Sentry or kentia palm BegoniasJasmine
PothosSpider plantKalanchoe

Plants with Special Light Requirement

The light requirement will vary according to the season, where plants require more light in the summer and less in winter.

Notably, plants native to tropical regions require more consistent light throughout the year and may need additional artificial lighting during winter to remain healthy.

Similarly, growing cannabis requires more light than other indoor plants.

Provide anywhere from 18-24 hours of light with a blue light spectrum between 400 and 500 nm during the vegetative stage from high-intensity discharge (HID) lights.

Germinating seeds indoors would be an exception, requiring a uniform light intensity throughout the growing period.

The light should be between 200-400 umol m-2s-1 for 14-16 hours each day and kept 2-6 inches above the tray, which is best achieved by medium or bright light.

How to Choose the Artificial Light for House Plants?

Choosing the best artificial lighting for your indoor plants would depend on their requirement, time of the year, and indoor growing conditions.

As previously mentioned, the best artificial lighting would depend on whether you are growing a low, medium, or bright light-loving plant.

plant under artificial light
Choose grow light with appropriate intensity and spectrum to support healthy plant growth.

Here is a table describing what artificial lighting your indoor plant would require.

Low LightMedium LightBright Light
A low light is similar to minimal lighting obtained from the north windowIt is similar to moderate lighting received from east or west-facing windowsIt is similar to bright light received from south-facing window
50-150 umol m-2s-1
50-250 foot-candles
10-15 watts
538-2690 lux
150-250 umol m-2s-1
250-1,000 foot-candles
15-20 watts
3690-10763 lux
250-450 umol m-2s-1
>1,000 foot-candles
>20 watts
>10763 lux
Only "understrory plants" like Dracaena, English ivy, and cast iron plants are appropiateAppropriate for tropical plants like Begonia, Frns, Rubber plant, etcAppropriate for succulents, citrus, vegetables, flowers, and fruits
It is not appropriate for germinationGermination is possible but may take longerIt is appropriate for germination
Plants are likely to grow slowlyPlants will grow moderatelyPlants will flourish

Based on this fact, you can choose the type of artificial light bulbs for house plants.

Light TypesSpecificationLimitations
LED-Light emitting diode is the most economical grow light choice
-It produces very little heat
-It offers wide spectrum of light
-Higher up-front cost for larger space
-Increasing intensity would require adding multiple bulbs
Fluorescent-Old school lighting option for budget-friendly growers
-It produces minimal heat so is less likely to burn the plants
-Available in T5, T8, T12 and CFL options
-Inappropriate for germination
-Do not last long
-Uses more energy
Incandescent-They can cover large space for indoor garden
-Cheaper up-front cost
-Good for medium light plants
-Only emits 10% light, the rest is emitted as heat
-Energy inefficient
-Not appropriate for bright light plants
-Offer high far red light
HID-High intensity discharge is good for bright light loving plants.
-Appropriate for germination
-Appropriate for indoor garden, greenhouse, and farming
-Energy inefficient and expensive
-Not appropraite for few small or ornamental plants
-Heats up too quickly
Halides-High-pressue sodium and metal halide
-Appropriate for wider areas
-Commercial light supplements for greenhouse and farms
-Only applicable for large scale farming
-Heats up too quickly
-Requires more distance between the light and plants

Best Grow Light for Plants Indoors

Here are a few best grow light recommendations, including some stylish grow lights for indoor plants.

GE Grow Light for Plants-Advanced red spectrum with high output PPF 15
-Highly energy efficent
-Appropriate for leafy, veggies, and fruits
-Hung at least 5-6 inchs above
AeroGarden Harvest Elite-High performance, full-spectrum LED light
-20 watt LED
-Appropriate for herb and ornamental plants that grow up to 12 inches.
-Includes guormet herb seed kit (6 pods)
GHodec Grow Light for Indoor Plants-6000K spectrum with 126 LED clips
-Equiped with 5 Red + 37 Sunlight White LEDs
-Timer setting available (4h,8h,12h)
-360 degrees adjustable goose-neck
-Height adjustability available
BESTVA 4000W Led Grow Ligh-4000 watts LED grow light appropriate for indoor garden
-Full spectrum lighting with 2x higher PPF
-Equipped with high-speed mute fans and aluminum radiators
-Applicable for germination, veg, and blooming by choosing custom setting
iPower 1000 Watt HPS-1000W digital dimmable electronic ballast (0%, 75%, 100%)
-1 x 1000W super HPS bulb 2100K; 1 x 1000W MH bulb 6000K
-6-inch air cooled hood reflector
-Appropriate for germnation, veggies, and fruits.

Wrapping Up

Keeping your indoor plans flourishing can be challenging without optimal lighting, especially when the sun is scarce.

Therefore, make the best of lighting by using sunlight and compensate with artificial lighting wherever possible.

However, be wary about the light requirement, intensity, duration, distance, and light spectrum for house plants before buying a grow light.