My Propagation Set-up

By Mike Kenchington, Fordingbridge, Hants, U.K.
Chamaerops No. 51 - published online 22-04-2005

Left: Various stages of root development of germinating Parajubaea cocoides, including a twin germination. See article on page 16.
Centre: The general arrangement in propagator, showing the heater and various types of boxes that are used for sowing. See article on opposite page.
Right: Parajubaea cocoides, germinating in a sowing container. See article on page 16.
Photos by Mike Kenchington

This article describes the propagation set-up that I have now been using for about 12 years. I have been germinating palms and cycads for over 15 years. I have a floor-to-ceiling cupboard that contains the hot water tank for the house. This tank occupies approximately half the cupboard, which leaves me with a space of approximately 3' x 2.5' x 2.5' (90 x 75 x 75 cm) to use as my propagator. The hot water tank will keep the temperature between 23°C & 29°C depending on whether or not the boiler is running. To get better control of the temperature in there, I have installed a 160-watt electric tube heater that is wired to a thermostat; the whole set-up cost just over £80 (€ 110). By using the thermostat and opening the door at night I can regulate the temperature to 30-32°C for 16 hours and 19-22°C for 8 hours. There is no lighting in the propagator. Some of the boxes I use for containing the propagating medium are old Phostrogen buckets; I also use margarine tubs, or basically anything as long as it has about 4" (10 cm) of depth. The bigger containers were bought from a local surplus store. 0nce seeds have germinated and are producing the beginnings of a leaf shoot, I pot them up and transfer them to my greenhouse where the temperature varies between a night-time low of 14°C and a varying daytime temperature of between 14°C to a maximum of about 35°C in the summer months.

My sowing medium is a 50/50 mix of Perlite and Vermiculite. After many years of experimenting I finally arrived at this mix. I have found that vermiculite on its own holds too much moisture and perlite on its own is too dry. I have found that the above mix works well for me and causes less problems with seed rotting in the mix. You can obviously vary the ratios slightly to say 40/60 either way, but any more and the above problems begin to recur. I have also found that you can reuse the mix by sterilising it by pouring boiling water through it until boiling water comes out through the bottom. I use a kitchen colander for this purpose. I no longer use any peat or organic type of medium for sowing. I did try this in my earlier days, but I always had the same problems occurring. No matter how carefully I sterilised the medium (boiling water or in the microwave), I always had problems with seeds rotting. The main reason for this is that the compost holds too much moisture. I didn't cure this problem until I started using the inorganic mediums perlite and vermiculite.

When I obtain the seed, I soak them in clean, lukewarm water and place in the propagator for 24-48 hours. After soaking, I clean off any residual pulp from the seed, as this will rot very quickly in high temperatures. The palm seeds I sow under the surface, usually covering with about 1cm of sowing medium. For cycads, I half bury the seeds. The only palm seeds that I sow this way are Parajubaea. I never crack any seeds open as suggested by some growers; my attitude is there isn't anybody sitting under the tree in the wild with a hammer to break open the seeds so why do it under our conditions. All seeds will eventually germinate if you provide the right temperatures and conditions.