Introduction: Plants can be propagated by a variety of methods, with mixed results. Success may be understood differently by each person and may be affected by the species and health of plant, environmental conditions (such as time of year, lighting, and temperature), the skill of the person performing the procedure, and the materials at hand.
Purpose: Determine whether Tradescantia zebrina cuttings result in more aesthetically pleasing (read: compact, rather than leggy or etoliated) plants when propagated by placing in water to form roots or when dipping in rooting hormone, then placing in soil.
Hypothesis: The cuttings dipped in rooting hormone and then in soil will result in a more aesthetically pleasing plant.
Method: This experiment will use two easy methods of propagation of a Tradescantia zebrina that make use of tools at my disposal.
Method 1: Water propagation
- Snip five 2- to 3-inch cuttings from the mother plant.
- Trim the lower leaves until a node is exposed.
- Place node of each plant into a glass container with filtered water, keeping leaves out of the water as much as possible.
Note 1: Due to the shape of the container, cuttings require more length to keep the leaves out of the water than the cuttings in Method 2. Some of these cuttings are angled between different nodes and leaves, resulting in more overall length.
- Place the glass container and cuttings in a well-lit window.
- Change the water every 5 days to 1 week, as needed to keep the water clear.
Method 2: Soil propagation
- Snip five 1- to 3-inch cuttings from the mother plant.
- Trim the lower leaves until a node is exposed. Trim the cutting so that the length between the node in the soil and the top leaves is as short as possible.
Note 2: Due to the shape of the nursery pot, cuttings in this method are much shorter than in Method 1.
- Place well-draining potting mix into a nursery pot that is as small as possible.
I used a 2.5 inch square pot and made a mixture of 1 part perlite : 1 part African violet mix, because it was on hand.
- Dip the stem and node of each plant into rooting hormone.
I used Wilson liquid root stimulator.
- Bury the stem past the first node into the potting mix.
- Place the nursery pot and cuttings in a well-lit window.
Note 3: Although they are placed about 6 inches apart in the same window, the cuttings from Method 1 and Method 2 may receive different amounts of light, as they are shaded by an external tree or by nearby indoor plants.
- Water every 3 days to 1 week, as needed to keep the soil moist.
Observations: They both got equally leggy over the next two weeks.
Conclusion: No difference, even with the benefit accorded to the cuttings propagated in soil. Lighting is probably more important as a variable to ensure compact plant growth. I gave the water-propagated cuttings to a friend after transferring to soil.
Here is the in-soil prop; I’ll likely repot it with the mother soon to create a fuller plant.