Cuttings can also be placed in plastic trays covered with clear plastic stretched over a wire frame (Figure 2). Trays must have holes in the bottoms for drainage. The plastic will help keep the humidity high and reduce water loss from the cuttings.
With the exception of succulents, most cuttings need high humidity in order to grow properly. Until cuttings develop roots, they are very susceptible to drying out. If you don't have a bright area with high humidity, you can create a humid environment around the cutting by placing a clear plastic bag over it.
Place the pot in a bright area, but out of direct sunlight, so the leaves will receive the light they need but the plant will not get overly hot. The plastic bag insures that humidity around the leaves remains high, which slows the rate of water loss.
The sooner you can get your cuttings into a more normal environment with air flow and no dome, the better off they'll be. After about a week, remove the dome and monitor your cuttings to see if they begin to wilt. If they do, they're not ready to go dome-less, so try again in 1-2 days.
You want to keep things humid, but you don't want to suffocate your plant. Mason jars are another great option for smaller cuttings. Once you can see a few inches of roots, it's time to plant in soil. Clear containers are always best for this type of process so you can see what's going on.
Cover the Pot With Plastic
Place the container with the cutting into a plastic bag. The bag will keep the humidity high and hold in heat. Do not seal the bag completely because some airflow is necessary to prevent fungal rot.
Roots themselves are also light-sensitive, so despite the fact that they will absolutely grow in a clear container in sunlight, you will find more success and faster propagation as well as avoiding algae growth in a dark glass or opaque container.
Warm growing medium temperatures accelerate cell division which leads to faster callusing, root initial development and subsequent root growth. It also speeds up the dry-down rate of the growing medium, which also helps encourage better rooting. The best way to warm the growing medium is through bottom heat.
Cuttings need water for hydration, but also enough oxygen for roots to respire and grow. Using a substrate with adequate air porosity, and using the 1 to 5 moisture scale can help to prevent overwatering that leads to slow rooting and increased risk of disease.
From stick to root development (Stages 1-3), propagators sometimes use too little water or moisture, but most often provide too much water, which leads to leaching and waterlogged propagation substrates (Fig. 1), uneven rooting and loss of cuttings due to rot (Fig. 2) or botrytis.
Technically, you can transfer your cuttings to soil at any time. In fact, you can actually propagate directly into soil, however, it's much harder to do within your home. When you propagate in soil, you have to keep a good balance of soil moisture, air flow, and humidity.
Ideally, the bag can be kept shut from the time the cuttings are inserted until they are rooted in 10 days to a month. Another related hazard is seepage of moisture from the bottom of the bag to the surface on which it is resting.
Should we allow the cuts to dry out a little before sticking them in medium? No - while herbaceous cuttings are less likely to rot, they also root faster than woody plants because they contain less lignin in their stems. Don't give them time to dry out.
Give cuttings bright light but not sun. Keep soil moist but not wet. The cuttings should root within three weeks. Admit air gradually to wean the cuttings from their humid environment, then pot singly before outdoor planting.
Carefully remove excess leaves to reduce transpiration, so cuttings do not wilt. However, some foliage should be retained to allow photosynthesis to occur. Keep cuttings moist, cool and shaded (collecting in a damp plastic bag is a good idea) until you are ready to put them in a propagation medium.
The reason cuttings rot is that over time, the oxygen level of the water drops unless it's moving or oxygen is added. Not only do plants need oxygen in order to grow roots (and, indeed everything else), but the bacteria that cause rotting thrive in low-oxygen environments.
Several cuttings may be placed together in one container. Be sure to add fresh water as needed until the cuttings are fully rooted. Rooting will generally occur in 3-4 weeks but some plants will take longer. When the roots are 1-2 inches long or longer the cutting is ready to be potted up.
Auxins stimulate root formation on the stem cuttings, e.g., IBA, IBA-alanine, NAA. NAA is synthetic auxin while IBA is considered as both natural and synthetic.
Managing photosynthetic light during callusing is a balancing act. Enough light should be provided so cuttings can photosynthesize, producing the carbohydrates required to sustain the cutting as well as promote new growth, including root development.
It's important that your water propagated plants receive some light, but bright indirect light with no direct sun is important. They are growing new root systems and are fragile.
Adding supplemental lighting to cutting (clone) production can greatly increase the chances of a successful crop, along with faster root emergence and crop times. If the Daily Light Integral (DLI) is too low during propagation, leaves will be unable to get enough light for photosynthesis and rooting can be delayed.
Step 1: Prepare the propagation box – Find or purchase a clear plastic storage bin with a lid, and wash it with soap and water. It's important that the bin is completely clear so that light can reach the cuttings. The size of the box doesn't matter as much, but be sure to get one that's large enough for your use.