How much light do indoor plants need

How much light do indoor plants need?

If you want to bring indoor plants into your house, you may already have a place in your apartment for them. Your houseplants will only thrive if they get enough light. It's not that simple, though. Even if you place the plants by the window, they do not always get enough light - if it is a north window. Indoor plants have different needs for light. While some like it bright, others cannot stand direct sun and also feel comfortable in a corner or in partial shade.

Light requirements of indoor plants according to pictograms

Indoor plants that are offered in the DIY store or garden center usually have care instructions in the form of a pictogram. You can also find such pictograms in care instructions on the Internet. Small pictures show how much light and how much water the plants need. Depending on the plant, the light requirement is given as sun, partial shade and shade. What does that mean in concrete terms?

- Sun: 1,000 to 1,500 lux, at least six hours of full sun a day
- partial shade: 800 to 1,000 lux, three to six hours of full sun a day
- shadow: 300 to 800 lux, less than three hours of full sun a day.
On average, indoor plants need around 1,000 lux to photosynthesize and thrive.

What is a Lux light?

Lux is the unit of measurement for illuminance. The illuminance varies depending on the season and the amount of sunlight. If the sun shines in summer, that amounts to around 100,000 lux, while the illuminance on an overcast summer day is only around 20,000 lux. On an overcast winter day, the illuminance is only 3,500 lux. In an east or west window, indoor plants get about 2,000 lux in winter. With every meter that you place your plants away from the window, they get about 1,000 lux less. To measure the illuminance for your indoor plants, you can get a lux meter as an app on your smartphone. As a rule of thumb, even plants that get by with little light should not be more than two meters away from the window.

How indoor plants react to a lack of light

When you get a houseplant as a gift, you don't always know what it is called and what demands it makes. You can tell that a plant is suffering from a lack of light from a few reactions:

- If the distance between the leaf nodes increases, the plant stretches towards the light.
- If new leaves remain smaller, it is too dark.
- Plants with patterned or structured leaves show no or only a few leaf patterns and structures.
- The plant sheds leaves so as not to exhaust itself when there is a lack of light.
- If the plant usually has white patterned leaves, the leaves turn green. The plant needs to produce more chlorophyll to compensate for the lack of light.

Pay attention to the direction of the compass

Depending on the direction in which the window is located, the indoor plants receive different amounts of light. You don't have to do without indoor plants even with a north window. Here is a selection of plants, depending on the direction you are facing.

- South window: Cacti and succulents, weeping figs, candlestick flowers - all plants that like it bright and can also tolerate direct sunlight
- East and west windows: Green lily, bromeliads, orchids, money trees - all plants that prefer partial shade
- North window: Efeutute, rubber tree, lucky feather, cobbler palm - all plants that get by with little light.

Indoor plants outdoors in summer

In summer you can take your houseplants outside on the terrace or balcony. They then get significantly more light and reward you with lush growth and beautiful flowers. Even a rain shower does not harm many indoor plants.

Tip: You should pay attention to the acclimatization period so that the leaves of your plants don't burn outside. First you should put them in the shade on the balcony or terrace and slowly get used to the sun.