Propagating House Plants - Methods And Instructions
Cuttings is the most common indoors plants propagation method. Some plants which can be propagated with this method can be very hard to do "without the correct equipment and conditions", while others are very easy and can even be started in water (soil is best though).
The Various Cutting Methods
This process is the most common of all. Stems and side stems are the main sections of the parent plant which produce further growth for leaves or flowers, that can be cut if they're producing growth, but not when they're flowering.
Take the cutting with a very sharp knife or blade below the node (leaf joint), which can be anything from 3in - 5in long and remove the lower leaves (so a few are left at the top of the stem). All you need to do now is dip the bottom inch of the stem in rooting hormone and place it in a hole you would have made deep and wide enough (you can use a pencil) to place a couple of inches of the new stem inside (use cutting soil). Propagating during spring and summer will improve your chance of success.
Many plant types without a main stem can follow the leaf cutting method. There are three ways of propagating a plant with leaf cuttings, which is a leaf cut with an inch or two of petiole (shoot with leaves), just the leaf or a section of a leaf cut.
The most common way is to take a whole leaf with a petiole. All three methods have a similar process depending on the type of plant. Many succulents and cacti are propagated with just a leaf because there is only a crown of leaves and no woody type stems. Peperomias and saintpaulias are propagated with a leaf and shoot, and then streptocarpus and sansevieria with a leaf section cutting. Follow the propagating method advised that's specific for each plant, as mentioned in the guides on this site.
Taking a root cutting involves removing a decent size root section and then cutting the section into 2 - 4 inch segments. It's probably best to plant up to 5 or more root cuttings to improve the chances of success. Make sure the end of the root which was closest to the top (crown) of the plant and soil is placed just below the surface, which will produce the new shoots. Root cuttings are usually taken during the winter (dormant period), ready for the new growth to appear in spring for the new and parent plant.
Some plants can be propagated by taking cane cuttings, such as cordyline, dieffenbachia and some dracaenas. This process involves taking a stem and cutting it into 3in long sections. These sections should at-least have one node or even better a bud that's appeared, which is where the new shoot will sprout from and then roots should grow underneath the cane. The cuttings are placed on top of the soil horizontally and pushed half way into the soil, although some growers stand the cane upright.
Other Cuttings Advice
Re-potting: Once you know the foliage from the cutting has started to grow well enough (new growth on stem tips or plantlets for leaf cuttings), it's time for it to be placed in it's new pot which should be around 2 - 4 inches wide. With leaf cuttings the parent leaf will need to be removed from the plantlet before re-potting.
Pot, rooting bag or propagator: Many cuttings need a good moist and humid environment to be placed in once they've been removed from the plant, although succulents and other leaves need some drying out time. The most basic way to propagate is using a pot with a polythene sheet cut and placed over the pot with an elastic band around the pot. Rooting bags with suitable cutting soil can also be used or a plastic propagator, which is a tray with a lid that has to have cutting soil placed inside for the new cuttings.
Bottom heat: Professional growers that propagate many thousands of plants use methods which provide the bottom of the plant heat, speeding up the growth process. This can be done on a smaller scale with a heat mat placed under a suitable propagator or with an electrically heated propagator.
Soil: I find it's easy to buy and use ready made seed and potting compost, which is sold in most gardening stores. It's good practice to add a thin layer of sharp sand to the top of the compost for many succulents and cactus plants.
Placing cutting in water: There are some plants which form roots from cuttings easily in water, although it's not really the best way to propagate. Once the cutting produces roots it then has to be potted, so I fail to see the point of placing it in water first unless it's a temporary solution until a pot or soil is found.
Air Layering, Division, Plantlets and Seed Sowing
Air layering is the most interesting way of all propagation methods used on large stemmed plants which have become leggy, too big for their living space within a room or they're hard to propagate with cuttings. Plants like the Swiss cheese or rubber plant can be done this way, if stem cuttings are not available to cut or you want a good section of a stem to begin a new plant.
To propagate first make a cut in the stem, which should leave more than 2ft of plant tip above. Two cuts should be made through a couple of millimetres of bark one inch apart, and then remove the inch section of bark (this is where the roots will form). A small bag is made (using a small plastic sheet) and placed around the cut section - filled with rooting medium, then tied at each end to secure the bag and moss around the cut stem. Roots will form within the bag, which will be removed once enough roots have formed with the top section of the stem - to be re-planted.
Propagating using this method will produce a plant which is much bigger than a stem or cane cutting, because the upper section of the parent stem and it's leaves will be replanted with the new roots, so it's had a good head start.
Division is quite an easy process of dividing one or more parts of the whole plant, although care should be taken when cutting a section the parent, if needed. Most will come part easily by hand. Spider plants, ferns, African violets and others are propagated by division.
Plantlets and Offsets
Plantlets: The spider and mother of thousands plants produce baby plants on small stems (stolons) called Plantlets, which are easily re-planted. There is not much explaning to do here, apart from the bottom section of the plantlet needs to be potted in moist soil or placed in water before potting.
Above is the mother of thousands plant, which you can see the small plantlets around the edge of the leaves.
Below is a large spider plant with plenty of baby plants that can all be potted.
Offsets: Offsets are formed at the side of the main stem on various plants, which are also called pups. These can be removed from the parent plant and re-planted. The pups need to have grown to a reasonable size before removing (remove as much of the plant from the parent as you can) which depends on what species the plant is. Once removed you can follow the same process as taking stem cuttings.
Parent Aloe Vera Plant With Four Offsets
Sowing seeds is a method mainly used by plant nurseries and professional growers because it's time consuming and they need the correct environmental conditions, which the average indoor gardener may find hard to provide. You can purchase seeds for various plants from stores and online, such as the solanum capsicastrum and strelitzia reginae spring to mind.
The process involves placing seeds on the top of the soil with space between each of them in a pot or tray and a plastic covering, then water thoroughly. Place a layer of compost over larger seeds (not small seeds) and provide the pot or tray a warm environment of about 60 - 75ºF (15 - 23ºC) with very little light (large but warm cupboards are a good place to sit them). Once the seeds have germinated and the first sign of life breaks the surface, take the cover off the pot and bring them out into a light location without direct sunlight.
Interesting experiments within the home can be done with all sorts of fruits and beans, which can be educational for the kids - even if the plant does not last very long.
Note: While this is a general guide - a grower should try and follow the specific advice for each species. You will find propagating options for each plant in the A -Z list of plants here.
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