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Houseplants function as living décor, making your home look beautiful. They also introduce nature into sterile indoor environments, injecting mood-boosting natural greenery. Finding creative ways to display your plants is the fun part, but before you do that, it is essential to consider the living conditions which plants require. The most important of these is light.
Seeing the Light!
All plants require light, and with most houseplants, the more you give them the better. Light through a window is already about 50% less intense than direct sunlight outdoors and light levels plummet as soon as you move just a few feet away.
However, some plants will tolerate shadier conditions, although, as light is required for growth, their growth rate will slow down.
Light Bulb Moment
Ordinary light bulbs don’t provide plants with the light that they need
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Ordinary incandescent light bulbs simply aren’t intense enough to keep your plants happy. Plants require both red and blue light as well as a small amount of green light. Different light spectrums have specific effects on plant growth. Light bulbs don’t provide the wide colour spectrum of natural sunlight.
How much Light?
Direct light, Bright Light, Indirect light, Shade – what does it all mean? Let’s cast some light on the tricky terminology. Move away from your screen and look out of the window!
South or West Facing Windows
The majority of plants will love a South or West facing window
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Type of Light: Bright Direct Light to Bright Indirect Light
A South or West facing window will offer the most amount of light and the majority of plants will love you for it! Not only is the light more intense, but the hours of sunlight are longer.
However, the quality of light can vary enormously during the day. Plants which receive intense midday sun directly onto their leaves can be scorched by the intense light. They may also get too hot. Provide shading for these periods.
Plants positioned a few feet away from south or west facing windows will still receive plenty of bright indirect light and grow happily.
All cacti and succulents need the bright light of a South or West facing window
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Houseplants happiest on south or west facing windows:
East Facing Windows
Philodendrons will enjoy the indirect light of an East facing window
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Type of Light: Bright to moderate indirect light
Positioned directly in front of an East facing window, your houseplants will receive moderate indirect light for most of the day with some bright light directly on their leaves in the morning. However, as morning light does not tend to be as intense as afternoon light, they are unlikely to need shading.
Houseplants for East Facing Windows:
North Facing Windows
Aglaonema, or Chinese Evergreen, is able to cope with low lighting conditions in North-facing rooms
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Type of Light: Indirect low light to shade
Rooms facing north receive no direct sunlight. Try to place your houseplants as close to the window as possible and select shade loving specimens. Moving just a few feet away from a North facing window can quickly plunge your houseplant into deep shade, especially during the winter. If you would like to brighten dark corners with greenery, it’s a good idea to consider rotation.
Houseplants for North Facing Windows
Is my houseplant getting too much light?
Given that indoor light levels are so much less than the outdoors, the general lighting conditions are unlikely to pose this issue. However, sun scorch can happen on south-facing windows where light directly hits the leaves. Some plants are more susceptible to sun scorch than others. Providing shading only during these times may be impractical, in which case, adjust the position of your plants so that they avoid direct rays.
Is my houseplant getting enough light?
Lack of light is one of the most common houseplant problems. Your plants will exhibit tell-tale signs if they are lacking in light. Look out for:
Leggy or spindly growth
If you have left your plants to grope in the dark, this is the most obvious sign. In low light conditions plants will fight to survive, stretching towards the light. The intervals, or nodes, between leaves and side shoots will lengthen. Plants may flop or collapse as growth becomes spindly and uneven.
Small leaves
Lacking energy for growth, plant leaves may become small and stunted. Lower leaves may fall off and aren’t replaced with new ones.
Slow growth or no growth
Plants may show little enthusiasm for putting out growth, and just ‘sit there.’
No flowers
Flowering houseplants need light to bloom. Lack of light will reduce or stop flowering.
Leaf colour
Variegated leaves may revert to all green. Leaves may become paler in colour (although this is most often a sign of other problems!).
Maximising Light for your houseplants
Leaf Cleaning
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Leaves inevitably accumulate house dust. That dust not only impairs a plant’s looks and reduces the lustre of shiny leaves, but it also acts as a light-blocking screen. There is no need to buy expensive cleaning products, a damp dust cloth will suffice. Don’t press hard on the leaves as you dust them and avoid cleaning young, new leaves. For spiny and hairy leaved plants, such as African Violet, use a soft brush or blow the dust away.
During leaf-cleaning, take the opportunity to give your plant a general health check. Remove any debris, pull off dead leaves and inspect the plant for any pests or diseases.
Rotation
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If lighting conditions are poor, the priority is to make sure you select the right shade-loving species. Then practise plant rotation. Regularly turn your plants to ensure that they get sun on all sides. This promotes more even growth. Give a boost to plants which have been sulking in the shade by moving them onto a sunnier window sill for a few weeks.
Houseplant Holidays
Freeing your plants from the house to enjoy a summer holiday outdoors will improve their health. Not only will they enjoy bathing in increased light, but they will also have the benefit of fresh air and rainwater.
However, houseplants become used to the amount of light which you give them. Given that even a sunny windowsill provides significantly less light than the outdoors, they can scorch surprisingly quickly if placed outside in natural sunlight. In fact, just a couple of hours outdoors can cause ugly leaf burns. Be sure to increase light exposure gradually and always place them in a shady spot.
Guiding Light
Light is a crucial factor for the successful growing of houseplants. Always give them as much light as you can. Firstly, make a realistic assessment of the light levels in each room according to its orientation. Secondly, try to find suitable positions as close to a window as possible. Thirdly, always allow your selections to be guided by the lighting conditions. So, in duller rooms, be sure to choose tougher plants which can tolerate lower light. And lastly, maximise light for your houseplants by cleaning leaves, rotating positions and giving them the occasional outdoor summer holiday!
For more on keeping your houseplants as healthy as they can be, take a look at our dedicated houseplant hub page. Find new varieties to try, care tips and growing guides.
Or see our other Houseplant Blogs:
- Houseplant Watering Guide
- Houseplants For Pets
- Fun Houseplants for Kids (& Grown Ups)
- Decorating with Houseplants
Annelise Brilli is the Horticultural Copywriter for Thompson and Morgan. Annelise caught the gardening bug from her mother, whose tiny backyard was crammed with a huge collection of plants. As an adult, she had a career change into horticulture, gaining a training apprenticeship with the National Trust at Powis Castle Garden in Welshpool. She went on to work in a range of private and public gardens, later running a garden design and maintenance business. She is passionate about sustainable gardening and has developed her own wildlife-friendly garden which she has opened as part of Macmillan Coastal Garden Trail.
Great blog again Annalise. As someone who has a fairly dark flat it was very useful. Thank you.
What you don’t mention is …is better to have light from above? Although this brings with it the problem of massive heat loss through an uninsulated glass roof does it improve your plants life?
Yes light from above will maximise light levels providing there’s no overhead shade from buildings etc. You would need shading for the hottest part of the day though. Of course, the ideal environment for most houseplants would be a tropical glasshouse – but that’s not a luxury most of us can afford!
Now this is useful info. I don’t know if I’ve read such a coherent and helpful guide to plants and lighting. Thank you.
Thank you Nick. Hope your huge collection of houseplants are growing well.