By Paul Mundweil
Many people in trying to become self sufficient in the garden take to doing their own propagation which is a fun and cost effective way to increasing the plant stock you have. When it comes down to it, propagation is really not that hard. The most important things to know are to attempt it at appropriate times of year, and look after your tender plants effectively.
This article for the most part will talk about cloning or cutting propagation, and once that has been covered a short note about seeds.
A cutting is usually an active growing tip of a plant cut, and placed in a specific soil medium so that it can become a new plant. Actively growing young plants are preferred to older plants, because of their more effective reproductive vigour.
Plant material desired is green wood on the tips of plants (soft tip cutting), because it grows roots quicker than other plant material. The next option down would be semi-hardwood which is plant material which is just past the green wood, and still able to snap between two fingers. The soft wood chosen is then tested by seeing it bends a lot when pressed the thumb and the middle finger. If it passes this test (doesn’t bend too much) cut a tip off the plant between 6 and 10cm long. Remove the leaves carefully from the bottom ⅔ of the plant. Remove any flowers and reduce the size of any large leaves. The reason is because we are trying to reduce the leaf surface. The more leaves the more water the cutting will need. The need for too much water could ultimately lead to an avoidable death of the cutting.
Next step is too choose the medium or soil which the cutting is to be placed in. The area of the stem of the plant in the soil needs good ventilation/drainage but not too much to leave it dry at any time. Tender plants grow tender roots. Tender roots can’t afford to dry out. For the reason just explained, the best readily available medium is a 50/50 mixture of coarse sand and cocopeat. Cocopeat is a peat moss made from composting the fibrous husks of the coconut. It is a great and easily renewable resource and proven to be great for the plants. A plant propagation mixture is bags can be found in hardware stores and I have found this as a useful alternative to making your own. My favourite propagation mix is 50/50 cocopeat and perlite ( a clay particle expanded in an 1,000 degree oven), which has sufficed for many of my cuttings.
After soils we need to set the atmosphere. In general any propagation atmosphere, needs to be fairly constantly humid. Too humid and you can kill them, too dry and you do the same. Also some air flow/ventilation if it is not below 15° Celsius helps them to avoid being too humid. I have found that some larger propagation setups get too carried away with the humidity, which can either delay root growth or kill root growth through rotting in the soil. It is surprising, what you can sometimes get away with if the humidity is good. From experience treating them too much like babies will be the worst for them. On some occasions in summer in wet/humid climates I have struck cuttings within 2 -3 weeks in shade houses with 360° ventilation, and sometimes on warm days with a mist spray in the morning and evening.
Temperature another important factor, is important for root growth of your cutting. In cooler climates [i][i] cuttings should be attempted only in summer. In warm temperate to subtropical[ii][ii] a six month period overlapping summer, and tropical all year round. Under 15° Celsius is too cold for a majority of cuttings.
Easy propagation tips. I once told a friend in Spain to cut a section of his Ficus benjamina
about 1foot long (30cm) and place it in a bottle of water and it will grow roots. Years on he is happy and shows me the plant. Also in Germany i told a relative to cut a section of an indoor succulent and just put it in the soil. She has many new baby succulents. Soft mint type plants like spearmint, applemint,
pennyroyal and oregano, can be propagated easily in summer, especially if they have rooting powder coated on their in soil parts. There are many soft plants like this that will have roots between 1 week and a month, depending on temperature and treatment of them
2 easy setups for the home gardener or gardeners in confined spaces. 1. Coca cola bottles. Wet the medium completely , let it drain in a normal pot for ten minutes. Leave the
cap on the bottle. Cut the bottle level from ¼ of the distance from the bottom. Place the medium in the bottom of the bottle. Place your cuttings in the medium. Give the leaves a mist, for example once a day, then slide the upper half of the bottle over the bottom half. It should then be air tight. Place the bottle on a sunny window sill. 2. A propagation tray filled with propagation medium, cuttings and water proof domed lid is also a good incubator for the cutting in warmer months. The soil can drain freely and the leaves and medium should be misted and water daily.
Lastly seeds. Propagation mix sand and cocopeat is probably the best medium. Soil, must be wet. Hard seeds try to soften their coating by putting them in water 24hours before planting them. The rule of thumb. Plant the seed to the depth of the seed itself, e.g. 5mm seed, put 5mm of seed over the top of them. Dust like seeds, sprinkle soil over the top and firm it down. Always protect seedling trays from heavy drips of water. It can lead to loss of the seed. Seeds that are thin and can fly in the wind, grow roots well, if gravel is placed over the top instead of soil. It also protects them from loss because of heavy drips.
Hope you find this article useful. In future articles we will also deal with important specifics of propagation and provide some videos to show what we have been talking about.