How much light do Succulents really need? Part 1 of 2 – Lack of Light

How much light do Succulents really need?

It’s a question that is asked quite often, and unfortunately, there is no universal, one size fits all answer. Succulents are a family of plants that originate from all around the globe, from all different types of environments - Tropical, Arid and even Alpine. It’s what makes them so fascinating to grow, as they offer so many different colours, textures and shapes.

The best approach in narrowing down what your succulent may need in terms of light, is to research what area it originates from, and replicating that at home. In combination with that, my best advice is to simply keep an eye on your succulent. If it is showing signs of lack of light, it’s time to make some adjustments.

What are the signs of lack of light in succulents?

To answer this question, at first I wanted to put some succulents in a dark room and take some photos after a week or two to highlight the visual signs of lack of light. Then I thought I should have some ‘control’ plants grown out in our nursery to offer as a comparison. THEN, I took it one step further and added to the experiment some plants grown under artificial grow lights, and you can read all about that in part two of this article coming up next month.

THE EXPERIMENT

The Plants

The succulents I have chosen for this experiment are ‘Echeveria Morning Beauty’ and Crassula ‘Buddah’s Temple’. I chose the Morning Beauty because of its bright blue colour, and for its rosette shape, the Buddah’s Temple I chose because its deep green colour, and its upright growth habit. 

The Conditions

All the plants are from the same batches – They are the same age, same potting media, same pot size, and have had the same watering schedule up until now.

The control plants in this experiment will be placed out in the nursery, and they receive about 8 hours of sunlight per day. They are under hail net which filters out a small fraction of light. They are watered every day, as it is the end of summer.

The indoor plants will be in my living room – A room I know to be too dark to grow succulents. Placed on a side table near a window, you may think that would be sufficient, however on the outside of the window is a rather deep undercover area. So, although there is some light coming in, it is not enough to promote healthy growth (except for my ZZ plant, which I’m pretty sure grows on magic pixy dust and not light, because it is absolutely thriving in that room!). As for watering they will be watered every second or third day, when they start looking a little dry.

THE RESULTS
Day 1

Day 3

Day 7

On day 7 you can see that the indoor Echeveria is starting to lose its colour towards the centre of the rosette. The Crassula is growing a little elongated as it reaches for light, and It is also starting to get a little pale in colour.

Day 12

By day 12 the Echeveria has lost more colour from the centre, and is flattening its shape compared to the control. The Crassula is much taller than the control now, and you can start to see the leaves flattening out, similar to the Echeveria.  The leaves on the control Crassula by comparison remain nice and compact.

Day 15 – The Final Comparison

As you can see, the differences are quite stark side by side on day 15, the last day of the experiment. The Crassula fared much better indoors than the Echeveria, and that’s due to its green colour which makes it more tolerant of low light conditions.

Signs of lack of light to watch out for:

Lack of colour in the foliage
Elongated growth
Flattening of rosettes or the separation of leaves
Leaves becoming soft, and sponge-like.

What can I do about it?

If you start seeing these signs in your succulents, it may be time to relocate them. You can give them the best chance to get healthy again with a few simple tips:

1. Try not to put them into a bright sunny position straight away, as this can shock them and they will go downhill quite quickly. A gradual introduction of more light is the way to go. 

2. Avoid watering too often during this period – This especially applies to rosette types, as an intake of too much water could cause them to rot.

3. Don’t fertilise a sick plant – This generally applies to most plants, not just succulents. Wait until you see some fresh healthy growth to apply a fertiliser.

4. Prune if you can – This applies to upright types, if you cut back the elongated growth, new growth will shoot away and you should start to see a nice compact plant.

5. In the case of the Echeveria, it may be too far gone to save that one rosette, BUT you may find that it will pup because it is in a stressed state. Those pups will send down roots and grow to fill up the pot space.

I hope this article points you in the right direction about finding the ideal spot in your home to grow succulents. Hopefully it will help you identify signs of lack of light, and what you can do to help them out.  In our next newsletter, we will have part 2 of this experiment, which deals with the idea of ‘too much light’, as well as growing succulents under artificial grow lights.

Read Part 2 of this experiment: How much light do succulents need? Part 2 – Is there such a thing as too much light?