Grow Light Terminology


You might want to grow, all year round, generous edible herbs even if you have long dark autumn-winter or you do not have a south face oriented window. In this case, artificial grow light is a must. However, the market is flooded with different grow lights with so many features to look at that overwhelmed me the first time I approached them. Here my advice on what to look at when deciding on buying a grow light for your indoor herbs.

How to choose the right grow light? The features you need to look to choose a grow light for your indoor herbs are the following:

  1. Light Intensity: PAR Chart
  2. Light Distribution: PPFD Chart
  3. Spectrum: Targeted or Broad
  4. Coverage Area
  5. Price
  6. Wattage

Let’s dive in all these features, one by one, by using simple words to allow you to decipher all the technical aspects. Moreover, for further information, a guide on the best commercially available grow light will be available soon.

At the end of almost every section you will find one or more “tip for starters” paragraphs that will provide you with some valuable tips, especially in case you are approaching for the first time the world of grow light. 

Final disclaimer: this guide has been written with the beginner gardener in mind. Hence, it is not oriented to more advanced grow light application where significantly large coverage area, multiple light sources and tend (to guarantee a perfectly controlled environment) are typically adopted, are not here discussed.

Grow Light Features: How To Decipher Them

You might have looked online to quite a few grow lights and found several technical (or cryptical) features reported on the selling page as the one shown below for one example randomly pick in Amazon:

  • Coverage Area: 8.61 Square Feet great for bigger indoor grows
  • Lifespan: 50,000hours
  • Power consumption: 125 – 125W
  • Input Voltage: AC85~265V
  • Design to replace a 400W HID in a 3′ x 3′ area, with the most uniform spread of PPFD imaginable
  • Our proprietary RGB White spectrum is comprised of 6 wavelengths with the highest absorption by Chlorophyll A and B
  • Plug Type: UK Plug
  • Working Temp: under 15C
  • Full 5 years warranty
  • The LED grow light has an enhanced spectral output covering full PAR (380-780nm) which promotes photosynthesis for growth & blooming.
  • Low Power Consumption

At this point, you might ask what is the LED power, how does it affect herb growth. You might question whether that 50,000 hours are going to be sufficient for a long use. You read terms like PPFD, white spectrum wondering whether you need to go back to school again. You might wonder if such a (relatively) expensive lamp can be replaced with a cheaper one and, if so, how this will affect your herbs. 

Some of the terminology you need to know to choose the right growth light – Background image from Pete in Flickr

I am here to help. I am going to explain to you in simple terms all these concepts and more. For simplicity, I am going to delve into every single aspect that you need to know to choose your grow light and improve your knowledge on the field.

Light Intensity And Distribution: Two Key Aspects

The light produced by a grow light is characterised by its intensity (how bright is the light for the) and how it is distributed across the area illuminated by the grow light. Forget one of these aspects and you will probably fail, or at least undermine, the development of your herbs. 

Here I will go through these two aspects explaining their meaning and impact on your plant so that you will be able, by yourself, to understand what you should go for.

Light Intensity: Look For The PPF 

PFF or Photosynthetic photon flux radiation is probably the first and most important concept you have to be familiar with if you really want to succeed with growing indoor your herbs. 

Skipping the technical details, PPF defines the total “amount” (properly called intensity) of plant-light produced by the grow light. When I say plant-light I mean the light that the plant uses to develop. I will restate it again, the amount of light that the plant (not human) will see. 

To better understand what I mean, without going into physical details, you just need to know that any light produced by any source is a mix of different light colors (the rainbow colours such as yellow, blue, red, orange etc…) in different amounts. Imagine to be a painter and mix 2-3 colours together in the same spot as your canvas. The final colour is a combination of those initial ones. Light behaves in the same way. This is a key concept that every gardener, from beginner to expert, must know before even looking for growing plants (read it again if not clear).

Every source of light is a combination of different light colour – Photo from Ivan T. in Flickr

If you sink this in your mind it is very easy to understand what I mean when I say that plants use mainly red and blue light to grow! It means, that of any light they receive, they absorb (and use) mainly the blue and red components while less of the others. The light that the plant needs is not any generic light, it is a specific light also called PAR (Photosynthetically Active Radiation) that I will also call plant-light.

If you understand this, you are almost halfway to understand how to grow with indoor light and how to choose them as all grow lights are designed to make lots plant-light in the most efficient way possible. Manufacturer measures the total amount of plant-light produced by the grow light in PPF (Photosynthetic Photon Flux). This is an indication of how bright the light produced is for your plant. Higher the PPF higher the amount of light produced and the higher the number of herbs you can grow with one single light.

Light Distribution: The Big Deal is The PAR Chart

Knowing the total amount of plant-light produced by your grow light (PPF), although important, it does not tell you the light intensity that your plant receives, essential to understand how much it can develop. Suppose that I through you 10 tennis balls (the PPF) in your direction but without specifying how many you are able to catch (not many in my case!).

The same applies to plant and grow light. We need to know how much plant-light actually reaches the plant. This is quantified through a number called PFFD (Photon Flux Density measured in a complicated unit of measure, forget it for now) whose distribution across the illuminated area is given by the PAR chart (or called footprint).

This is not only a function of the light manufacturer (PPF and light technology used) but also of the 1) distance of the plant from the grow light and 2) location respect the source. These are what the gardener can control of its grow light.

1) Distance: As you can easily guess, the higher the distance from the grow light the less light will arrive at your herb that, in turn, can slow its growth. Double the distance from the plant and you are reducing 4 times the intensity of the light reaching the plant.

Tip for stater: you know that you can regulate the height in order to cover more area (and reduce the light intensity). If you have less light-demanding plants (like herbs) you might want to position the light further away so to have also more covered area, and vice versa for other crops such as tomatoes.

2) Location: Something that many forget (but you will not!) is that many grow lights have a unique (or few) sources of light concentrated in the center. Hence, any herb that is placed below the center of the grow light will inevitably receive more light (or, a high PPFD) that those place at the corner of the area.

This difference is not minimal. From reading many manufacturers grow light datasheet, I noticed that a herb placed in the border can receive 10 or more times less light than a herb placed in the center! Yes, you read well. This is a massive difference that you need to be aware of you are planning to use such lights for many plants.

A PAR chart, like the one shown below (simplified form) a real example, provides the light intensity (PPFD) around the light source (assumed to be at the center, yellow square). It this real example adapted from a manufacturer datasheet, each square reports the amount of PPFD across the area served by the grow light. As you can see the PPFD oscillates from 720 (at the center, where the light source is) to as low as 184 in the corner (3+ times less).

Example of a PAR chart (adapted) from a real grow light

Other grow lights might present several light sources (of smaller intensity) spread across their area. The value will be higher at the center but the difference with the border will be smaller. Remember, every PAR chart is referred to a specific height (36” in the above example). More serious vendors provide PAR chart for different light/plant distance.

Tip for starters: When choosing among multiple grow lights you should look for the one with the most uniform PAR chart. If you have a large area to illuminate prefer multiple small grow lights that one single large. This will provide way more uniform PPFD.

Tip for starters: If you are in a low budget you can increase the uniformity of your light in the border with one simple trick. Just place at the border of your light area some pieces of cardboard vertically standing, surrounding the light area, covered in aluminum foil in order to reflect part of the light that otherwise will be lost back inside the growing area.

Do Higher PPFD Benefit Plants? 

A higher light intensity (PPFD) might not be better for your herb as each plant has specific light requirements. If you give me a plate of delicious pasta, for instance, I would definitely appreciate it (who wouldn’t). What happens though if I am obliged to eat 10 plates of pasta? Well, the results will not make me happy! The same applies to plants that, as for me and you, are living organisms with their own (feeding) limit!

Too much light can damage your plant. This amount varies significantly from plant to plant but keep in mind that any light intensity above a PPFD=1500 will damage any herb that usually strives with way less.

Tip for starters: Even before looking online for grow light, you should be clear on the type of plant (in our case herbs) you want to grow as this drives the light requirements and so the coverage area. Indeed, for instance, tomato plants require lots of light while herbs like basil will be definitely damaged by such a bright light source.

Coverage Area Of Grow Light

The coverage area of a grow light is strongly correlated with the amount of light they emit. Hence, the higher is the PPF the higher will be the area that they can cover. A single grow light might cover up to a 5x5ft area (30.5x30.5cm) although the majority are more towards a  4x4 – 3x3 and 2x2 ft (1.2x1.2 – 0.9x0.9 and 0.6x0.6 m). The above are typically the coverage area that hobbyists and starter gardening adopts. 

What you need to check to understand the coverage area is the PAR chart. You need to ask yourself what is the need of your plant and, as a consequence, 1) find (Googling) the PPFD required by your plant. Hence, the coverage area is given by the zones in the PPFD char where the PPFD is equal or/and above the PPFD required by the plant. This will define your area. 

Remember that the PAR chart is a function of the distance of the grow light from your herb. Hence, if by any chance the PPFD (provided for a defined height) is too high (for instance 1000 when you need 500) then you need to place the light further away (need to check another PAR chart for a different height) so increasing the coverage area. If the manufacturer does not provide multiple PAR charts for the different height you can simply assume that every time you double the distance you have to divide by 4 the PFPD value.

Tip for starters: if you are looking for a grow light online and you do not want to waste too much time looking at each single PAR chart (or in case it is not available, a reality, especially for cheap, grow lights) you can use the wattage (as this information is always available on the manufacturer website) to roughly quantify the coverage area.

Every 10 watts provide a coverage area of 10 cm2 for crop requiring lots of light (tomato) or, in case of herbs like in our case, 10 watts for each 30cm2 (such numbers applies to the LED-based grow lights). Hence, a lamp of 130W (the equivalent of 3-4 large normal fluorescent light that you might use at home) can cover an interesting area of 400cm2 (a square of side 20cm) sufficient for 2-3 small potted herbs.

A practical example: Supposed that, like me, you want to grow basil. You chose the grow light whose PAR chart is shown in the figure above. Basil is a herb that needs only a modest PPFD of 500. Hence, given the above PAR chart is referred to an area of 3x3 feet where only 3 out of the 5 square horizontally and vertically present a PPFD above 500 the area is a square with a side that is ⅗ of 3 that is approximately a 2x2’ square area. 

Of course, this should be good enough to provide the right surface area but none prevents you to experiment and try different arrangements. Moreover, if you also have a bit of extra light (a nearby window even if north faced) might increase the overall light intensity allowing slightly larger coverage area.

Spectrum: Choose The Wrong One And Your Herb Will Not Grow

Let’s skip the nitty-gritty physical detail of the spectrum. Do you remember that any light can be described as the combination of different light colors (the rainbow is the proof of it)? Well, the spectrum tells you how much of each light color component weight in the total. A spectrum with a heavy blue component means that the light we are referring to has lost of blue color light in it. If such a ratio is very high the light might even start looking blue at our (human) eyes.

Grow lights are an interesting piece of technology as can produce light with a specific spectrum that the manufacturer wants. Based on that there are two common types of grow light in the market:

  • Target spectrum: this type of light is heavy in a certain light color component. Indeed, long studies and (photomorphogenesis) experiments have discovered that plants use different colors of light for different purposes

    More precisely, in vegetative state (developing leaf) plants use more blue light while in the flowering state they use more red light. Now you know why and what does it mean if you read that light is vegetative or flowering targeting. If you are more into the science you can also watch the interesting video below.
Experiment: Red Light vs Blue Light -How Spectrums Affect Plant Growth- LED vs CFL
Effect of red and blue clour on plant growth
  • Broad or full white spectrum: This type of light “contains” all colors imitating more closely the natural sunlight. Indeed, even if to different extents, plants absorb all colors, not only blue and red, but everything in between like green, yellow and orange.

Often more expensive grow light offers the possibility to tune the spectrum at your will by regulating the amount of red/blue light emitted. This is achieved in a continuous way or with a simple switch that tunes from vegetative/flower light and vice versa.

Also remember that, although uncommon, some manufacturers can define the spectrum using its temperature in Kelvin (K). Red corresponds to 2100K (flowering), blue corresponds to 6500K (vegetative) and 4000K (green/yellow light). These are the only 3 numbers you need to remember, that’s it.

Tip for starters: I do suggest a broad spectrum (white) light. This provides a more natural light color by which the plants evolved to grow with. If you are not oriented to massive herb production for sale purposes (and you are not if you reading this guide) this should be your choice. In the long term such light might provide slightly less harvest than more sophisticated high spec targeted grow light, however, white LED light are a way more efficient way to produce light and so impacting less on your electricity bill. 

Moreover, white light allows to spot color anomalies on the plant (like white/brown/yellow spots on leaves) way more effectively and so increasing dramatically the chance to save it in case of illness. I would also go for a fixed spectrum, especially at the beginning you need to get in the routine to care about your plant and manage the light system properly, without bothering with changing light colors (for now at least).

If you really want a targeted spectrum light then I suggest using the one for full plant cycle with a fixed spectrum (to make your life easier) as you might want to experiment and use for all different stages of your herbs.

Wattage: Higher Power Does Not Imply Brighter Light

The Wattage is correlated with the energy (power to physically precise) required by the grow light at your wall power socket. If all grow lights were produced equally a higher wattage would imply a higher PPF (total light emitted) and a higher PPFD (light received by the plant) and your life would be so much easier. 

However, this is not the case. Light technology (for instance LED and fluorescent lamp) and light features (presence of a lense or spectrum for instance) can have a massive difference in the growth light efficiency. So it is totally possible that two grow light that draws the same amount of power have two (quite) different PPFD. This is because if the grow light is producing light of the “wrong colors” (not used by the plant) that requires power but the PPFD (based on the plant-light, not any generic light) will be very low! This typically a problem of cheap grow light relying on old light technologies (incandescent). 

Important to remember that higher wattage (the number you find after “W”, like 20W), the higher will be the bill extra money you need to pay to provide electricity for up to 12 hours to your grow light. I will write an article on the matter offering you some examples of the extra money you need to pay on your bill.

Trip for starters: choose a white LED light as the best in terms of efficiency. Even a small lamp of 20-30W is more than enough for 1-2 small potted plants. A grow light of 500W or above it start becoming quite important in size as it might consume more than the majority of your house appliances (especially in EU countries) considering that must be kept ON for 12-16 hours daily. Hence, such high power range is only recommended for the more serious and experienced gardeners.

High-Pressure Sodium (HPS) lamps are still adopted as grow light although nowadays are losing popularity at a fast pace, especially among small and medium gardeners. Indeed, HPS emits light mainly with yellow and red components. Such lights are then promoting more flowering and fruiting than vegetative grow, something that you do not want for your herbs

Moreover, HPS  produces heat, a lot, reducing their efficiency as well as obliging the gardener to use the cooling system, increasing complexity and cost. Moreover, for such reason, HPS light should be kept away from the plant to avoid burn damage, so further decreasing the efficiency of the light as the PPFD will inevitably decrease. Moreover, they have a short lifespan of around 15000 hours, a fraction of other technologies. Nowadays, this type of light technology is used only by commercial growers as a supplement of already in place lighting system and it is not at all suggested for small indoor (house) gardeners.

Fluorescent lights have been widely used to grow indoor herbs and plant more in general. They have a longer lifespan compared to HPS and they last much more. An experiment performed in a controlled environment proved that the temperature will rise of only 11 degrees when the light is just a few centimeters away from the plant as detailed in the youtube video below.

T5 Fluorescent Grow Light Review - VS LED Comparison - PAR and Heat Test
A brief overview of T5 fluorescent lamps

The most common nowadays used fluorescent lights are the so-called T5 (because of their dimensions). If you find T8 and T12 grow light they are old and you should avoid them. T5 lamps have a lifespan of around 20,000 hours and such lamps are still in use although I am expecting them to become less and less common in favor of LED. However, if you find a good T5 as a good deal or second-hand market is a total go. You can check them and their price on Amazon.

Light Emitting Diode technology (known as LED) is definitely the most efficient and overpowering the market as you can also notice by searching in any online shop to grow light. Eight out of 10 results, if not more, will be LED-based grow light.

Why LED is going to dominate the market? Well, I see three main reasons that you need to know:

  1. It is more efficient than a fluorescent lamp. Hence, more light with the same power output;
  2. They produce virtually no heat. This allows them to be placed extremely close (even in contact) with the leaves without any detrimental effect;
  3. Because of the above, no ventilation system is generally required reducing cost and complexity, massive plus especially if you are a starter gardener;
  4. They have a massive lifespan of up to 100,000 hours, the equivalent of a dozen years at 12 hours daily usage, the highest by a massive margin among the other available technologies;
  5. LED technology can produce highly specific light color components targeting exactly what the plant needs like a blue and red light. This also explains why LED light also look purple (mix of blue and red) at our eyes. Indeed, not by coincidence, the first LED-based light growing system was based on the previously discussed “target spectra”
Small grow light with LEDs that produce blue light and red light (you can notice the bright blue spots in the picture). The result is an overall purple light – Photo by F.D. Richards in Flickr

Although LED lights are the most expensive to buy their high efficiency, long lifespan, lack of heat released definitely pay off, in the long run, making them cheaper if running costs are taken into account. So I do personally foresee this type of technology taking over in the future becoming dominant especially for small applications. 

Tip for starters: adopt a LED-based system for your first grow light. You will have fewer headaches and better results compared to other light technologies. At the moment you can also find cheap options that, just to start, are decent enough. For a review on the best grow light for beginner gardeners, I wrote an article here.

There are also other “extravagant” lights such as Sulfur plasma that are showing the highest efficiency of all. However, as every new technology, further testing and development are needed and their price is well above what is, at the moment, economically convenient. 

Price: Not Always The Most Expensive Is The Best

The features that you might look for in a grow light will affect its costs. However, if you are just starting in the grow light area you are in luck as the price of LED light, the best technology available in the market, is in constant drop.

Indeed, online you can easily find LED grow lights as cheap as (around 7$) as the one to up to 2000£ (2500$) and if you are going to a professional scale and more specialized selling platforms, the sky’s the limit.  What is the difference between an expensive light and a cheaper one? And more importantly, do you really need a very expensive one? The answer is no and to understand why I will compare the features of a very cheap light with a high spec one so you can see what makes a grow light expensive and understand by if it wants you really need based on all that we learnt before. 

Such a comparison is shown in the table below.

FeaturesLow SpecHigh Spec
NameGladle E27 36W 220V 72 LEDsAdvanced Platinum Series P300 300w 12-band LED Grow Light
Price$$$$
Wattage36 W180 W
Coverage AreaNot specified (probably 10x10cm)4.5ft x 3.8ft coverage @ 18″(1.40 m x 1.15 m @ 45cm)
Controllable SpectrumNoYes (Vegetative State and Flowering stage)
Lifespan50,000 hours (around 5.7 years of 12 hours daily usage)100,000 hours (around 11 years of 12 hours daily usage)
Warrantynone5 years + 90 days money back
TechnologyLED – it has 2 different types of LEDs each one producing a specific color of light (52 LEDs producing red and 20 producing blue light)LED – it has 12 different types of LEDs each one producing a specific color of light that blended together creates a spectrum that matches the biological requirement of any plant
ManufacturerGLADLE (China)VIPARSPECTRA (USA)
Weight50g (1.7oz)6kg (13 lb)

What can you learn from the above table? Here my 2 cents:

  1. Wattage: Although the wattage (the power required at the power socket) of the most expensive lamp is 5 times (from 36 to W180) higher, its price is 150 times higher (from around 5 to $800). Hence, you can conclude that is not the wattage that affects the price;
  2. Controllable spectrum: the most expensive grow lamp has the capability, through a switch, to switch between an intense blue light (vegetative state) and an intense red light (flowering). This is a factor that evidently drives up the price as missing in the cheap lamp as well as in many middle ranges (around $100) grow lights;
  3. Lifespan: the most expensive grow light is using better quality LED (apparently produced in the USA, not in China) that guarantee double the lifespan of the cheaper version. This also drives prices up significantly;
  4. (Quality of the) Spectrum: this is another factor that drives the price up. Indeed, the most expensive lamp here analyzed adopt 12 different types of LEDs creating a spectrum that (as claimed) matches very closely the spectrum biologically required by the plant to grow best (even better than under natural sunlight). However, after a bit of digging, I surprisingly found grow lamps of $80 that claim to have the same feature as this one on Amazon. Hence, such spectrum quality affect the price, but not dramatically;
  5. Warranty: 5 years warranty implies a large and effective customer service that definitely drives costs up. Cheaper lights have no warranty as the one analyzed or only a shorter period of time (1 or 2 years). 
  6. Weight: the most expensive lamp weight hundreds of times more than the cheapest one. This because is equipped with a fan system. Although this increases the price, in my opinion, this has only a marginal effect. Indeed, also middle range lamps (one the $80 dollar range) have similar features.
  7. Manufacturer: Here you definitely pay also the reputation of the company producing it. A Chinese company cannot be compared to a known USA brand in an EU or USA market. Trust is important and so the price will inevitably reflect it.
  8. Coverage area: the consequence of a higher power is a higher coverage area of above one-meter square for the most expensive grow light. This is enough to have 6 or more plants under it or even more light-demand ones such as herbs. The cheaper brand does not provide any data but given the power and also the comment found online it can be inferred that is enough for 1 single pot

Hence, based on the above differences what you should choose? Well, if you are a starter gardener and you want to save money you can definitely renounce:

  1. a 12 LED-based spectrum, two colors can be enough as you might not be interested in matching perfectly the plant spectrum. This will lead to a lower than optimal harvest, but remember, you are growing for pleasure and sustain your family and potentially your friend’s needs for herbs, not for commercial purposes; 
  2. You can also give away the larger surface area and opt for a smaller size grow light (that will be in the range of the $80 dollars).
  3. I would not renounce to a decently well-known USA or EU manufacturer. Usually, their customer service is way more responsive and more reliable. Also, their components are often of higher quality and last longer.

Now you are aware of the key factors that drive up the cost of a grow lamp by such comparison. Hence, especially if you are a starter,  the most expensive grow lamp, although of high quality, might not be the right one to start due to its higher number of features and significantly large size area and considering that you might need to have this lamp hanging from the ceiling. 

My personal suggestion is to start small with just one little grow light, get familiar with the herbs you are growing, experiment with height and distance relative to the grow light and only when more experience playing with multiple plants at the same time and extend in a modular fashion your grow light system (by adding a light nearby).  

Hence, I would go for the cheaper brand, as a low-risk investment that will definitely benefit the and herb you are growing.

If you are still undecided you can always look at my recommendation here for my best grow light pick for beginners when all the above factors are considered.

What Do You Need To Start Using Grow Lights?

Space: You need space to grow your herbs. This is not only the space required by the plant itself, but you should take into account also the vertical space needed for the grow light that must be on top of the plants. Hence, no shelves on the way on top of the plants. Moreover, if you do not want cable hanging around all over the room you need to be close to a wall electricity socket. This is important as, if you are a beginner, you are going to manually water your plants and you do not want to trip over the power cord ruining your plant or, even worse, damaging an expensive grow light.

Moreover, the room where you decide to place your indoor herbs should be at a constant temperature and humidity. Around 20C (70F) and a low humidity are ideal conditions for most indoor herbs you might want to grow.

Tip for starters: if you have a basement underground this is the ideal environment as the temperature oscillates less during the day. Moreover, you might want to buy (or recycle, even from a dump) a desk where you can place your potted plants and the grow light. This will make your life much easier as you do not need to bend to water the plant. Moreover, it will keep the plant above the ground avoiding to make them too cold.

An empty basement, on top of a desk, can be an ideal starting point where to live your herbs – Photo by Dwight Stone in Flickr

In case you do not have a basement, a large bathroom might be ideal as the light can stay ON long hours without bothering anyone. However, be sure though that the ventilation is OK and it does not stay humid for a long time after a shower for instance.

If possible avoid your bedroom. Indeed, in case of pests attack your plants (aphids, ants, ladybugs, spider mites) you do not want such little guest hanging around you at night. Moreover, some grow light comes with fans that can make enough noise to be annoying.

Mind-setting and habits: This might be the easiest or most challenging to achieve. Indeed, it is very likely that you might need to daily turn ON the light for your plants. Forgetting for one day will likely not have any long term harm on your plants, but you must be pretty consistent. Good news is that many (not all) grow light have an embedded timer that allows them to turn off after a certain number of hours (8-12-16 usually). 

Tip for starters: Countless of study on habits development shows that you need to embed your new habit around an old one. You need the old habit to trigger/remind you of the new one. Hence, why not turning ON the light (and eventually watering) before taking your daily coffee at home or before reading the news. The old habit will trigger the new one until this becomes automatic.

Time: herbs in grow light do not require lots of care, just 1-2 minutes a day, however, they do require daily consistency. Forget the lights for a few days or even worst to water them and you can lose if it is not a strong crop;

Water: the amount of water you need strongly depends on your herb and can vary greatly. What I do recommend, to make your life easier, is to have in the same room a tap from where you can access water for your plants (basement again). Some more advanced gardener will use automatic watering systems but this will add cost and complexity that a starter gardener definitely should avoid. The amount of water depends on how fast the plant is developing, that, in turn, is also affected by the amount of light. If you increase the brightness of your light your plant is likely to require more water;

Tip for starters: buy a cheap watering pot with a long and tiny spout (in my resource page you will find some suggestions). In this way, you will avoid moving the plants around to water them. Indeed remember that when you start having multiple plants under a (quite likely) a grow light space might get quite tight (the lights might be placed almost in contact of the plant in case of a LED option). You do not want to move the containers around every time you need to water as this increases the probability that someday a plant will fall or braking the (potentially) expensive grow light;

Bulky and with a large ending sput watering cans are not recommended for indoor gardeners due to space constraint- Photo by chichacha in Flickr

Money: if you are starting small, with just one or two pots, and you do not want to spend lots of money even a decent compact fluorescent light of around 10-15 dollars for domestic application (daylight type if possible) is more than enough as you can check in Amazon. You can also use some old table or support that you can buy in some charity shops and a simple table lamp (I like the idea of giving a second life to objects, make them more useful, reduce waste, save money and make you more creative!). This is the cheapest approach but extremely valuable to build experience, learn how to grow herbs indoors;

Once you get used to you can go to more advanced grow light system whose cost can easily approach 100+ dollars/pounds (they are for more experienced, but still hobbyist gardeners) that I will discuss in a separate article in my recommended tools page.

Original Idea for Indoor Growing Light: DIY Inspirational

You are providing light and water, everything the plants need. Hence, almost any space in your house can be used to place your herbs and grow light. However, many gardeners come out with quite original ideas on how to maximize unused space with great “do it yourself” solutions. For instance in the youtube video below

Closet Farming | How to Make Everything

you can see how a simple closet, with some shelves, fluorescent daylight bulbs, a plastic liner can turn an unused tiny closet in a productive farming area. This requires lots of effort in maintaining and quite of DIY work, however it pays off tremendously and can be lots of fun.

Can you do something similar? To notice that, although is not explicitly mentioned, the plants are disposed in a specific order, from light hungry plants on top and less demanding on the bottom (mushrooms). The same must apply to your multilevel set up if you go for only one source of light at the top.

What if you have a cabinet that perhaps you do not use, or that you want to make the envy of all your friends? Well, our friend Sara Davis did just that. She transformed an already nice cabinet in a pretty small plant house. The idea is similar to the one proposed in the video above. She has placed two 75W Roleadro full spectra grow LED light at the top (here how they look like, on Amazon), supplied by a power cable that passes through a small hole done on the top of the cabinet. Also, smart the idea to use a cabinet with transparent shelves and to stagger the plants so as to maximize the light that each one receives. 

How to give a second life to a cabinet making it a perfect plant-house – Developed by Sara Davis

Again, the disposition should follow the plant needs. Indeed Sara placed high light-demanding plants on top. In case such plants will show signs of underlighting (such as small and dull leaves) a second couple of lights in the middle shelves might be an option. 

As Sara reported the LED light adopted doe not produce any significant heat and the temperature inside the cabinet is nice and cool, hence a good choice for such a “confined” application.

Humidity is not a problem neither as Sara lives in a relatively dry area. If this is not your case you might need a small ventilation system (two circular holes on the two sides of the cabinet with a small fun opposite faced to push air in/out should be more than enough).

Needless to say that all the above also applies to our favorite herbs. Now it is your turn. Any idea on how to turn empty spaces in charming herb paradises? Go for it!

Related Questions

Are grow lights water-proof? Not all of them, especially the cheapest ones. However, the waterproof version is recommended as plants, that can be very close to the light, are going to be watered regularly and accidental contact of water with the grow light might damage it easily if not water-proofed.

Is the light of grow light dangerous for human eyes? No, the type of light produced by led-based grow light system is not more dangerous than natural light as strictly designed to meet several safety standards (read for more details the CELMA website). If you stare for a long time a LED light bulb it can, of course, cause damage, in the same way, that happens when you stare at the sun.

Do LED light uses less electricity? Yes, among the available light technology LEDs are the most efficient producing the higher light intensity for the least of the energy provided.

Can you leave the grow light ON all the time? Yes, many plants will not suffer from a 24 hours light cycle although those that typically winter-blooming plant might not thrive as they would.

Further Readings

21 Tips to grow massive basil

Best container size for your basil

Best potting soil for your herbs

Best grow light for beginners


Andrea

A young Italian guy with a passion for growing edible herbs. After moving to the UK 6 years ago in a tiny flat, it was impossible to grow herbs outside. So I start my journey in growing indoor and so I decided to share my knowledge.

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