Reading Time: 8 minutes 🍃
Nearly all plants need sunlight to perform photosynthesis and produce food for the plant. However, some plants can grow without sunlight because they don’t need to make their own food. These plants gain their energy from other plants or from dead organic matter in the soil.
Both parasitic plants, which attach themselves to a host plant and suck the energy from the host, and saprophytes, that feed on dead organic matter in the soil or on the forest floor, are able to flourish without the aid of sunlight. They do not contain chlorophyll and cannot perform photosynthesis. They rely on other plants or dead organic matter for their nutrients and energy.
While plants that do not need sunlight to grow aren’t likely to be on your list of attractive houseplants and won’t produce food for your family, they can produce unique and intriguing blooms in the wild.
Total parasite plants (called holoparasites) depend entirely on the host plant for their food and cannot make food independently. These plants produce suckers, called haustoria, that burrow into the host plant and siphon off the food and energy they need to thrive.
Total parasite plants do not contain chlorophyll. They cannot survive without the host plant, but they can survive without sunlight.
(Striga asiatica) Red Witchweed is native to the grasslands in Africa and Asia. It produces hairy, green stems that reach heights of about 12 inches, with tiny flowers ranging from pure white or yellow to bright shades of red and purple. Flowers measure about ½ inch.
(Cuscuta sp.) Dodder includes a group of parasitic plants that includes more than 150 species. It produces thread-like, mostly leafless vines with clusters of tiny cream-colored or yellow flowers. Stems range from green to yellow and shades of orange.
(Pilostyles thurberi) This tiny plant is native to the southwestern deserts of the U.S. and lives on the stems of members of the pea family. It lives within the stem until a tiny flower breaks through the bark of the host plant. Thurber’s Stemsucker measures a mere ¼ inch in size.
Saprophytes get their food and energy from dead organic matter (or the fungi that feed on the dead matter) in the soil or on the forest floor. They do not have chlorophyll and cannot perform photosynthesis to make their own food. They are dependent on dead or decaying organic matter for their energy.
(Monotropa hypopitys) This little flower appears under fir and pine trees across the United States. It produces a slender white or reddish stem covered in scales with bell-shaped blooms that hang downward. It reaches heights of 4 to 13 inches and blooms from early summer to fall depending on the region.
(Rafflesia arnoldi) This amazing plant from southeast Asia produces the biggest flower in the world, often reaching 3 feet in diameter and weighing up to 24 pounds. While the flower is a magnificent sight, it emits an intense rotten flesh odor to attract carrion beetles and other pollinators.
(Neottia nidus-avis) The bird’s nest orchid lives underground, feeding off fungi in the soil. It is typically found under beech trees and sends up a yellow flowering stem in the summer.
Coral Root Orchids
(Corallorhiza) This genus of plants includes 11 species found in the Americas and Eurasia. They produce brown, yellow, purple, or reddish stems with up to 40 tiny flowers in white, yellow, purple, lavender, or reddish-brown shades. Depending on the species and the region, they bloom from spring to fall. Coral Root Orchids reach heights of 12 to 24 inches.
Can all parasitic plants grow without sunlight?
Total parasitic plants (holoparasites) and saprophyte plants do not need sunlight to grow as they do not perform photosynthesis to make their own food. However, some parasitic plants (hemiparasites) depend on a host plant for part of their food and perform photosynthesis. Hemiparasitic plants cannot grow without sunlight.
Common hemiparetic plants include Mistletoe, Velvetbells (Bartsia alpina), Indian Paintbrush, Indian Sandalwood (Santalum album), and Rattlesnake Plants (Rhinanthus). These plants all attach to a host plant and siphon some energy and nutrients from the host while performing photosynthesis and producing their own energy too.
Can houseplants grow without sunlight?
Many houseplants are native to tropical rainforests, where they have adapted to living in low light conditions, but they still need sunlight to survive. Without some sunlight, they cannot perform photosynthesis to make the energy they need to grow and thrive.
As a rule, plants with large, flat leaves are well-suited for low light conditions as the large surface area of the leaves allows them to gather more light. Although it seems counterintuitive, houseplants with variegated leaves tend to need more light.
Growing variegated varieties in low light will cause the plant to produce more chlorophyll to compensate for the lack of light. The leaves may turn solid green ruining the dramatic effect of variegated foliage.
Can you use artificial lights or grow lights for houseplants?
Houseplants need light to grow, but you aren’t limited to a sunny room. Grow lights provide a good source of artificial light and can be used when the lighting conditions are too low for your plants. The amount of light your houseplants need depends on the specific plant’s needs. Some, like philodendrons, pothos, and monsteras, are perfectly happy in low light and will thrive with artificial light.
Sun-loving plants, like cacti, need a lot of light to thrive. They may perform well with some natural sunlight supplemented with grow lights.
Houseplants may also benefit from supplemental lighting in the fall and winter when days are short and light is limited, especially if you live in a northern climate.
Can vegetable plants grow without sunlight?
Most vegetable plants need at least 6 hours of direct sunlight a day to flourish, but some can grow with less light. Green leafy vegetables like lettuce, spinach, chard, and other salad greens can grow in partially shaded areas in the garden. However, they cannot survive without some sunlight as they need sunlight to perform photosynthesis and grow.
Like houseplants, vegetable plants can be grown under artificial lights, if you have the luxury of a greenhouse or sunroom.
What about mushrooms? They grow without light, don’t they?
Mushrooms don’t make the list of plants that can grow with no sunlight because mushrooms aren’t really plants. Mushrooms are similar to plants, but they have developed a special skill for using enzymes to digest matter in the soil to make their food.
The mushroom you see emerging from the soil or growing on an old log is only the ‘fruit’ of the mushroom. The rest of the mushroom (fungi) lives under the ground and can stretch for acres.
Mushrooms typically grow in dark, wet areas under trees, but they can grow without any sun, as they do not perform photosynthesis to make their own food. They digest dead matter and convert it to energy to sustain the mushroom.
Will plants die without direct sunlight?
Some houseplants need direct sunlight to thrive and do poorly in less light, but many flourish with bright indirect sunlight. Others will do well in very low light conditions. To determine if your houseplants can survive with no direct sunlight, check the lighting needs for your plant. You can find this information on the plant identification tag, in plant descriptions in gardening catalogs, or on websites devoted to plant care.
Houseplants may be labeled for low light, medium light, bright light, or direct sunlight. Understanding what each term means will help you provide your houseplants with the right amount of light for them to thrive.
|Low Light||Areas with little natural light reaching the plant|
|Medium Light||Several feet (or across the room) from a sunny window|
|Bright Indirect Light or Bright Filtered Light||Near a sunny window but out of reach of the direct rays from the sun. A sheer curtain can be used to soften the light.|
|Direct Sunlight||The rays of the sun hit the foliage.|
Outside plants also need sunlight to flourish, but each has its own lighting needs. Lighting needs for outdoor plants are generally denoted as full sun, partial sun, shade, partial shade, or even dappled light. While the terms can be confusing (especially when trying to determine if the area is partially sunny or partially shady), each means a different thing. There is always some overlap between categories.
|Full Sun||6 to 8 hours of direct sunlight a day|
|Partial Sun||4 to 6 hours of direct sunlight a day|
|Partial Shade||2 to 4 hours of direct sunlight a day|
|Shade||Less than 2 hours of direct sunlight a day|
|Dappled Shade||Filtered light under trees with spots of sunlight|
|Full Shade||No direct sunlight|
Can you grow houseplants in a room with no windows?
Growing houseplants in a room without windows to let in natural light can be challenging, but it isn’t impossible. With quality grow lights, you can easily provide your houseplants with the light they need to thrive. Grow lights come in a variety of sizes to choose from.
But beware. Some manufacturers sell lights labeled as plant lights, but they are not the same as grow lights. Plant lights are designed to highlight the beauty of your plants under the light but may not produce the quality of light your plants need to grow. Plant lights are for ornamental purposes only.
If you choose to grow your houseplants under lights, purchase grow lights from a reputable source and read the description carefully. Be sure the intensity and size of the grow light are suitable for your purposes.
How do plants use energy from the sun to make their food?
Plants make their own food from the sun’s energy in a process called photosynthesis. The chlorophyll in the leaves effectively captures the light energy and uses it to change carbon dioxide and water into glucose. The plant then uses glucose to make cellulose and starch. Cellulose is used to perform vital tasks like repairing and elongation (growing) plant cells. Excess starch is stored in either underground tubers or the plant’s fruit. The starch is what gives fruits and veggies their sweet flavor.
Why are plants that grow without sunlight white or pale colors?
Plants that depend on photosynthesis to make their own food need chlorophyll to harness energy from the light of the sun. Chlorophyll gives plants their green pigment. That is why most plants have green leaves. However, plants that do not make their own food do not need chlorophyll. When the plant lacks chlorophyll it looks white or pale.
Some plants, like total parasites (holoparasites) and saprophytes do not need any light to survive. These plants do not contain chlorophyll and do not perform photosynthesis to make their own food. They rely on other plants, or decaying matter, for the energy they need to thrive. However. These plants are not suited for adding to your houseplant collection.
Houseplants, outdoor plants, and vegetable plants all need light to survive. The amount of light each needs depends on the plant. There are many low-light plants to choose from, but if you want to grow houseplants in an area that does not receive any light from the sun, you will need to provide them with supplemental lighting in order for them to live and grow.