Growing Cacti and Succulents Indoors
I have germinated seeds, raised seedlings and grown adult cacti and succulent with success for many years using some shelves and fluorescent bulbs. In this article I will explain the benefits of growing your plants indoors and I will describe how I built my installation for growing cacti and succulents indoors.
Why growing indoors?
You might have asked yourself this question while reading the above. The answer is not so hard. It’s fun! Offcourse there are important benefits (and some minor drawbacks) as well. In the lists below I have pointed out the most important pros and cons for growing plants indoors:
- Germinate seed and grow plants all year round
- Using space more efficiently
- Better control of light, water and temperature
- Reduce bug infestations
- Higher electricity bill
- Germinate seed and grow plants all year round
Because you are growing indoors under artificial light and with artificial heating you are not bound to the seasons and you can germinate seeds whenever you like. It is important to notice however that plants have some kind of biological clock. Especially older plants need a rest period. So, if you are only growing mature plants indoors make sure you tune down temperatures during winter and stop watering or water less. I only raise seed and grow 1-3 year old seedlings indoors so the resting period is less important in my opinion. During summer the warmth emitted by the fluorescent bulbs is enough to germinate seeds and grow seedlings. During winter you might want to use some heating pads to turn up the temperatures. Raising seeds indoors is beneficial even when you have a greenhouse. If you germinate your seed in december or januari you can give seedlings, especially seedlings of slower growing cacti and succulents, a headstart and place them in your greenhouse later when outside temperatures are higher. Growing older plants under artificial light can be very useful in forcing them into flowering (n.b. natural light conditions in countries like The Netherlands and England can be a real disappointment).
Using space more efficiently
In a greenhouse we are dependent on the light of the sun that comes in through the roof and the side. In order to achieve optimal growth plants benefit most from receiving light from above. We all noticed sometimes that when we place a cactus in the windowsil that it tends to grow towards the window, towards the light. This will misshape our precious cactus or succulent so again best is giving light from above. When you grow your plants indoors (in a spare room or corner of your hobby room) you can built a closet or rows of shelves attached to the wall. On each shelf (with fluorescent bulbs above it) you can place your germinating seeds, seedlings or older plants. By piling your plants on shelfs above eachother you are saving alot of space. I have 5 shelfs, each 40 cm wide and 120 cm long. A relatively small space because they are placed above eachother. I can place 25 germination trays in this installation!
Better control of light, water and temperature
Greenhouses are often open at the bottom and together with open windows humidity varies alot over the day and through the seasons. Temperatures and light vary in a greenhouse because they are (usually solely) dependent on sunlight. Together with the untidyness of most greenhouses growth conditions are hard to manage here. Indoors almost every condition is manageable. You can switch on light bulbs or switch them off using timers. You can more or less manage temperatures by switching on and of electric heating pads. I have everything on timers, also my ventilation fan. I create my day/night cycle by having my lights on timers (14 hours day, 10 hours night). When the fluorescents are switched off temperatures drop automatically from 22 degrees Celsius to 16 degrees Celsius. In this maner the natural temperature differences of night and day are created. My plants respond very well to it.
Building your indoor growth installation
Finishing this article I will describe which tools and materials I used to built my indoor growth installation. There are many ways offcourse. This one thats worked very good for me. Building an installation of 5 shelfs complete with lighting has cost me around 400 euro. All materials can be purchased at your local constuction market (Gamma, Praxis, Hornbach).
I prefer working with a so called “rail system” to attaches shelfs to the wall. I always use shelfs of 40 cm wide and 120 cm long. This is a standard size of shelf and exactly appropriate to place two regular nursery trays of 40 x 60 cm on. Place 3 rails (length depending on how many shelfs you want to place above eachother) vertically to the wall, seperated evenly from eachother. On these rails you can place anchors which will support the shelves. In this way each shelf will be supported by three anchors, seperated evenly along the length of the shelf. You can conveniently move the anchors up and down over the rails so you can adjust the space between the shelves. Very usefull for instance when you want a shelf with higher columnar cacti and the other shelfs with seedlings and smaller plants. At the bottom of each shelf (not the lower shelf offourse) small holes should be pre-drilled. In these holes screws will be attached to support the chains which will be attached to your fluorescent lighting systems. For each 40 x 120 cm shelf I use three 120 cm fluorescent bulbs, evenly divided over the width of the shelf. For bulbs I recommend using the standard 36 Watt Cool White types of 120 cm. They have the right spectrums and are cheap (n.b. it is wise to get new bulbs every year because the quality decreases over time). Using chains you can adjust the distance of the fluorescent bulbs to the plants you are growing. Very important for instance when you are growing Pereskiopsis or another plant that increases its height fast.
In the list below you find the materials I used to built my indoor growth installation:
- 15x 36 Watt fluorescents
- 6x wooden shelves (18 mm)
- 1x electicity cable (10 m)
- 16x connectors
- 15x anchor (shelf carrier)
- 3x rail (250 cm)
- 2×18 screw hooks
- 6×7 screw eyes
- 9×4 S-hooks
- 15x small metal chain (20-40 cm)
Good luck growing your own cacti & succulents indoors!