Growing From Spore Part 3 - Growing-on and Hardening-off

Well it's been a little while since we last had to do anything particularly taxing with our baby tree ferns. The main thing now that they are separated and planted in their own pot is that they are kept in nice humid and light conditions.

At this point it is probably a good idea to discuss a few issues with regards to growing under lights as this is undoubtedly an area which recieves little attention but deserves a lot. As I stated in the previous article; one can easily grow tree ferns from spore without the aid of supplementary light or heat provided the ambient conditions are acceptable. However there is no question that a small investment in equipment at this stage is going to help the growth of our little fernlings.

The reason for this is that with a light set-up we can have full control over the amount of light that our plants recieve rather than having to rely on natural daylight. If you have successfully grown your sporophytes during the long summer days you may find that just at the point where if anything you need the light levels to increase they actually decrease as winter approaches and the days become shorter. Along with these shorter days come a drop in temperatures and by mid-autumn our little ferns have slowed their growth rates to a snail's pace. This is where algae and mold can run out of control and we really don't want them to ruin our efforts.

Below is a picture of our standard propagator brimming with baby tree ferns. Note the air vents on the top are still shut but can be opened to decrease the humidity. But if you've got space and a bit of spare cash, the investment in fluorescent lights can definitely have a marked effect on the speed at which your plants will grow, particularly in winter.

One of the huge advantages of growing under lights is that you have complete control over the levels of light that your fernlings recieve. With a simple fluorescent light set-up you can connect a timer and set it to come on and off when you please. I generally have mine on for 16 hours per day but over 18 hours per day is not uncommon with other growers. Remember here that we have the added advantage of being able to tap into some heat which is being produced by the lamp which during the cold depths of winter is very helpful.

From my experience with growing tree ferns through a winter under lights I have found that the plants do keep growing even though the temperature is fairly low so long as they get plenty of light. When temperatures hit 25 degrees and all this light they rocket! Here's a set-up I use which is just a plain fish tank and I managed to find a very small T5 fluorescent lamp that clips on to the side of the tank. It's on a swivel arm so I can move it about and position it closer or further from the plants depending on what intensity I want them to recieve. Remember; the fluorescent light's photosynthesising abilities fall-off very rapidly the further the lamp is from the subject. Try and get your lamp as close as reasonably possible to maximise the photosynthesis. You can ofcourse add supplementary heat by placing a reptile heat-mat under the tank or by investing in a heated propagator but do be careful to keep an eye on the temperatures as heated propagators are notoriously unreliable. You don't want to cook them!

The gravel is optional by the way!

That's the most basic and inexpensive way of growing under lights but a trip to the hydroponics shop will unveil an almost limitless array of different forms of both heating and lighting for your propagator.

Regardless of whether you choose to provide supplementary light for your baby ferns or whether you choose to stick-out the winter months without and risk the ill-effects of a dormant growth period, at some point your propagator will end-up looking something like this below. Personally, as life is too short I will always use supplementary light at this stage but many people get by perfectly well without it. It just takes longer!

After many more weeks and months of slow growth our fernlings start to bulk-out a little bit and we consider subjecting them to life outside of the ultra-humid propagator. This Cibotium below is starting to outgrow its welcome and consideration must now be taken to start the hardening-off process.