Do you need Grow Lights before Seed Germination? – Do seeds need Light to Germinate?

Do you need Grow Lights before Seed Germination? Do seeds need Light to Germinate? These might be the first questions crossing your mind if you are planning to go for an indoor garden. If you are thinking of starting indoor gardening or planting some seeds indoors then you might know that the sunlight does not reach that well inside the house. Then you think about why not use a grow light for the germination of seed? But the reality check is that some seeds need Light to terminate while others don’t.

Key takeaways:

  • Many times seeds don’t germinate due to many reasons, can be light or can be other reasons like temperatures, oxygen, etc.
  • Not all seeds are grown in light, some need cold stratification and some need darkness to germinate.
  • Giving grow lights to the seeds for germination depends on the type of seeds whether they need light or not.
  • Many times when you buy seeds from the store after going through the instructions given on the package.

Do you need Grow Lights before Seed Germination?

Grow light Is an alternative for providing light to plants indoors. Where the sunlight is not reaching properly. As you have now understood that not all seeds require light to germinate So you can use light for the seeds that need sunlight or light conditions to sprout.

To be precise, for germination, the seeds don’t need fertilizer as they already have stored inside them for germination. The seeds that need light treatment will be needing to grow light indoors. These seeds will not germinate without light treatments.

What happens if you grow light before germination?

The grow lights can be provided to the scenes before germination only if they like warmth. Grow light will increase the temperature very little and give the light treatment to the seeds that will help them to sprout but not for all. In general, before germination, no light is needed by the way. Most of the scenes are stored in dark and dry conditions. Even during germination, the light should be given only after considering the type of seed.

Does darkness help the seeds to germinate? 

The seeds before germination either are stored in the store room in the dark conditions away from moisture or are packaged well. You must read the instructions given on the package before sowing the seeds. The seeds do not always need light to germinate; some seeds germinate better in the dark like the onion seeds. 

What seeds need light to be germinated?

The seeds of many vegetables, flowers, and fruits need light to germinate. They either need light treatment before germination or while sown in the soil they need ample light. The seeds will grow better and to the fullest if they get light. Though without light seeds still will be able to germinate in moist soil. The seeds that don’t light to germinate are celery, dill, arugula, cabbage, cauliflower, etc. The following are some seeds that need light to germinate:

  • Ageratum
  • Angelica
  • Begonia
  • Browallia
  • Calceolaria
  • Chamomile
  • Coleus
  • Columbine
  • Dill
  • Exacum
  • Ficus
  • Gaillardia
  • Gerbera
  • Gloxinia
  • Impatiens
  • Lavender
  • Lettuce
  • Lobelia
  • Marjoram
  • Nepeta
  • Nicotiana
  • Osteospermum
  • Pelargonium
  • Petunia
  • Poppy
  • Primrose (most species)
  • Rosemary
  • Saintpaulia
  • Savory
  • Snapdragon
  • Strawflower
  • Streptocarpus
  • Sweet alyssum
  • Yarrow

When to put light on germinated seeds? 

Most of the ceiling should be given light after they have terminated. You can use a grow light on the ceiling And keep the seedling under the grow light for 12 to 16 hours a day. As soon as the first seed starts to germinate you can turn on the blue light. How fast they grow depends on the type of seedling.

That won’t get proper light to become laggy and fragile. So yes you can turn on the grow light when seeds have already sprouted and the seedling has just appeared.

Tools and materials required:

The following are some tools that you need to have germinating seeds: 


  • Grow light
  • Adjustable chains for light
  • Outlet timer
  • Pen or marker
  • Spray bottle for water


  • Seeds
  • Seed trays or containers
  • Seed starting mix
  • Plastic bags or tray covers
  • Labels

How Much Light Is Enough

In case if you want to grow a plant by seeding it and that needs light to germinate, you need to start by growing it in a tray that needs light and place it in a Sunny South or north-facing window. In case it is a warm day then you can sow the seed directly in a thin layer of the soil. The direct sunlight during the early spring also provides a good amount of light and heat for seed germination.

The seed which doesn’t require any light for germination can be shown in a tray. You need to make sure not to expose them to light so that you can cover them with black plastic. You need to monitor the temperature after covering the plant so that the seed gets the proper range of temperature for germinating.

Using the plastic will help in wrapping the heat and will keep the soil moist by providing humidity to the tray.

What kind of light is needed for seedlings?

In order to buy a light for seed germination it is very important to get the right type of light for seedling as all the bulbs are not equally created. So here I have discussed which kind of light you need for seedlings.

Many people go to the hardware store where they can find tons of different types of light bulbs in which some bulbs are way too hot which will only cause harm to the seedling. So you need to buy the bulb according to the purpose they are made for as the bulbs needed for seed germination are called plant grow bulbs. These bulbs can be got from sale and then you need to put them into a lamp as they are available in different sizes. You can also use standard cool-white fluorescent bulbs for seed germinating. 

The following are some instructions that you need to follow:

  • In case, if you are not sure where to hang the bulb or how to do it then is will suggest you get a full system for example 4′ LED grow lights set up or a system which is 2′ long.
  • You can  also choose a T5 grow lights having 2′ long which is an 18″ length.

What grow light to use for the seedlings?

The white fluorescent bulbs and the ‘plant grow bulbs’ are mostly used by gardeners for indoor planting. The seedlings under their light don’t get burned and get the optimum level of light to grow. The T12, T8, and T5 output fluorescent lights are mostly recommended for germinated seeds. Among them, T5 is the most efficient option. Even the LED grow lights are great to use in indoor gardening having your germinated seeds. The grow light should not be fitted too near the seedlings. They should be at least 2-4 inches over the seedlings. I have already indicated the duration of growth of light to be given to the seedlings. 


What light is best for seed germination? 

The blue-green spectrum or the balanced light spectrum is effective for seed germination. 

How many grow lights do I need for seedlings? 

The seedlings need a grow light that provides 2000 to 3000 lumens per square foot of growing space. Seedling like that vegetables needs such a range of grow lights. The seedlings if are grown in the tray then the grow light writing 3000 lumens will help them grow effectively. 

Why do seeds fail to germinate? 

The fungal growth on the seeds, too much water, or even too little water can make the seeds less viable and they will not germinate. The seeds might stay dormant if they get very little water. 

Becky Decker

Becky Decker, our esteemed Editor-in-Chief, is a passionate gardener with years of experience in the world of horticulture. With her guidance, aims to be your trusted companion on your gardening journey. Featured In   Becky Decker’s expertise and gardening wisdom have been recognized and featured in various prominent publications, including: Yahoonews  Experience & Background   Becky Decker’s love for gardening has been a lifelong journey. She has honed her skills through countless seasons of planting, nurturing, and harvesting a wide variety of plants, flowers, and vegetables. Her deep-rooted knowledge is complemented by her Bachelor’s degree in Horticulture from the University of Green Valley.   Prior to leading, Becky worked as a garden consultant, helping countless individuals turn their outdoor spaces into vibrant, thriving gardens. Her experience spans over a decade, making her a trusted authority in the gardening community.   The Birth of   Inspired by her passion for gardening and her desire to share her expertise with a wider audience, Becky Decker launched in 2021. This platform serves as a hub for gardening enthusiasts of all levels, from beginners to seasoned pros.   At, we are committed to providing you with comprehensive guides, expert advice, and hands-on tips to help you achieve success in your gardening endeavors. Whether you have a small balcony garden or a sprawling backyard paradise, we have the information you need to make your garden flourish.   Our Mission is more than just a gardening website; it’s a community of gardeners who share a common love for nurturing the Earth. Our mission is to empower you with the knowledge and resources to create beautiful, sustainable gardens that bring joy and tranquility to your life.   Join Us on This Green Journey   We invite you to explore and embark on your gardening journey with us. Whether you’re seeking advice on planting techniques, pest control, landscaping ideas, or the latest gardening trends, you’ll find it all right here.   Connect with us, ask questions, and share your gardening stories. Together, we’ll cultivate a thriving community of gardeners and help each other make the world a greener, more beautiful place.   Let’s dig in and grow together at, where gardening dreams bloom!

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