How Many Lumens Do I Need To Grow Vegetables

Growing vegetables has become a popular hobby. It has gone from an activity primarily done by those who live in the country on a plot of land to a hobby those living in a tiny apartment enjoy doing. 

How are you supposed to grow vegetables in an apartment with no land and not much sunlight? Plant grow lights have come to save the day. Grow lights mimic the sun and provide indoor plants with the necessary light specifications.

Grow lights come with bulbs of different lumens. The higher the lumens, the brighter the bulb. For full-sun plants, a minimum of 2000-3000 lumens is sufficient for starting the seed. 

The later stage of the plant, the higher the lumens needed. In the flowering stage, medium lighting plants need 5000-10000 lumens. The specific number of lumens depends on the type of vegetable you are trying to grow and the maturity.

Plants growing under lights

Is 5000 Lumens Bright Enough for Plants?

For medium-light plants in their flowering stage, 5000 lumens per square foot is the minimum number of lumens for optimum growth. The plants can start from seeds with lower lumens, but they require a higher number of lumens when they begin to mature.

The average number of lumens for a plant near its flowering stage is 7000-7500 lumens. This number of lumens should give the plant sufficient light to grow. 

If you have a plant light that only emits 5000 lumens, you will get plant growth, but your plant will not be as healthy as it could be. 

How Many Lumens Does a Tomato Plant Need?

If you start a tomato plant from seed indoors, you will want at least 3000 lumens from your grow light. Any lower than this can cause a delay in germination or even no germination at all.

Once the seedling has emerged from the soil, 7000-7500 lumens are ideal for proper plant growth. When the plant is getting near its flowering stage, 10000 lumens will give you the best shot of getting those bright red, juicy tomatoes.

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If a tomato plant does not have enough light, it cannot produce fruit. Therefore, it is essential to provide your tomato plant with enough light to reap the benefits of gardening. 

Is 1000 Lumens Enough for Plant Growth?

Some bulbs only give off 1000 lumens. Is this enough for my plants to grow? Unfortunately, 1000 lumens is on the low side of lumens for optimal plant growth. 

You may get some plant growth from this number of lumens. However, if you have a very small area and only a plant or two, your 1000-lumen light bulb may be sufficient for your needs. 

Remember that the optimum number of lumens for mature plants is 7000-7500. Anything lower than this can cause a deficiency in plants. If you are just starting seeds and have them in an enclosed area, 1000 lumens may be enough for germination. 

You will want to upgrade to a higher number of lumens when the plant begins to mature.

Are 4000 Lumens Good For Plants?

The sweet spot for starting seedlings is anywhere between 3000 to 5000 lumens. If you have a bulb that emits 4000 lumens, you should be in good shape to start seedlings and upkeep a plant into its beginning of maturity.

The higher the lumens, the quicker the seeds will germinate. A 4000-lumen bulb is sufficient for seed germination and can last your plant for a while. 

If you cannot get a higher lumen bulb later in the plant’s life, consider moving the plant to a smaller area, which will give the 4000 lumens the most significant chance of being enough for the plant as it matures.

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Grow Light Lumens Chart

It can be challenging to find the number of lumens that a light bulb produces. Is an LED bulb or an incandescent bulb better for plant growth? Typically LED light bulbs to emit more lumens with a smaller number of watts.

Refer to the chart below to choose the correct bulb for the number of lumens you need. Remember, the higher the wattage, the higher the lumens.

Lumens (lm)Incandescent (W)LED (W)
260015025-28
160010016-20
1100759-13
800608-12
450406-9
Grow Light Lumens Chart

You will want to purchase a high-watt bulb to get a sufficient number of lumens. Your plants will not prosper unless they have enough light.

Are 5000 Lumens Enough for Plants

Starting seedlings and intermediate plants should grow well under a 5000-lumen light bulb. The recommended minimum number of lumens for starting seedlings is 2000-3000 lumens, so 5000 lumens will be adequate to start seedlings.

When your plant starts to mature, you may need a higher number of lumens to sustain the life of your plant. After emerging from the soil, the plant will be able to grow sufficiently with the 5000 lumens but will eventually need more lumens.

Depending on the plant type, your plant may need up to 7500-10000 lumens to thrive. However, if it is a smaller plant that does not flower, you may be able to get by with 5000 lumens through its life span.

Flowering plants and vegetables require a higher number of lumens to produce. Therefore, if a vegetable plant does not get enough lumens, you may not get to reap the benefits of having produce.

Plant under purple light on a table

How Many Lumens Do I Need for Indoor Plants

The number of lumens required for indoor plants is determined by the plant itself. Full-sun plants will require more lumens than partial-sun plants. Research the exact indoor plant you plan on having and find the necessary number of lumens for it.

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The general rule for non-flowering indoor plants is 10000 lumens for full-sun plants and 5000 lumens for partial-sun plants. 

If you plan on having a tree indoors its whole life, only tropical and subtropical trees are likely to survive because trees like oak and willow require a hard winter freeze, which will not occur indoors during the winter.

Consider your living conditions and what plants would work best, then research the number of lumens for that specific indoor plant.

Grow Light Lumens for Seedlings

Many growers start their seedlings indoors under a grow light in late winter through early spring, allowing plants to begin growing in the cold months so they are ready to transplant outdoors when the weather warms up.

The minimum requirement for full sun plants to start as seedlings under a grow light is 2000-3000 lumens per square foot of growing space. If starting seedlings for outdoor growth is your goal, a 3000-lumen light bulb should be adequate.

Grow Light Lumens and Kelvin

Understanding the connection and difference between lumens and kelvin is essential in growing healthy seedlings. 

In short, lumens are the bulb’s brightness, and kelvin is the color of the bulb. The two are directly proportional, meaning that a higher number of lumens also means a higher number of kelvin.

If you purchase a light bulb lower than 1000 kelvin, the blue light is below the adequate range for proper plant growth.

If you purchase a light bulb that is higher than 5000 kelvin, there is so much red light left out of the spectrum that your plants will slowly grow without vigor.

Plants require some blue light in the flowering stage of growth. Pick a light bulb somewhere between 1000-5000 kelvin for optimum growth.