The problem is if the cutting is too long the plant is more likely to wilt and stress. If the cutting is wilting it's far more likely to fail and not generate roots. Smaller cuttings will lead to better success rates and overall better outcomes for you and your cuttings.
Try to wait until at least 50% of the cuttings have good rooting before potting them up; however, for some hard-to-root species, you may be lucky with only 10% to 20% success.
Wilted cuttings are the result of increased transpiration from decreased humidity in the propagation environment. Humidity can be difficult to control. Most often, we refer to humidity as relative humidity or the proportion of water vapor in the air equated to how much the air could hold at a given temperature.
The technique is the same for almost all cuttings – cut a length of stem without flowers about the length of a pencil. Trim it neatly just below a node (the point where the leaves branch from the stem), and cut off the lower leaves to give you a bare stem. Put it down the side of a pot into gritty, free-draining soil.
Too much or too frequent application of mist / fog keeps the growing medium saturated, excess water will flow from the bottom of the trays and rooting will be delayed. Applying mist / fog too infrequently will increase transpiration from the leaves and cuttings will lose turgidity and could die from drying out.
Cuttings need energy to make roots. If the cutting has too many leaves – or even too long of stem – it will spend its limited energy keeping those alive instead of on growing roots. I love a long cutting for the potential of a new big baby plant, but it's better to cut it into sections and root them each separately.
The basic principle behind applying mist to vegetative cuttings is simple. Without roots, cuttings cannot adequately replace the water lost to the environment due to evaporation and transpiration mainly. To aid them along the beginning of their life journey we must replace this water loss with water applications.
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.
Cuttings are more difficult to obtain if you do not take them off a mother plant, because you need to know someone who grows a plant successfully. In addition, often less different types of plant varieties are available. The risk of cuttings carrying diseases and insects is present.
Herbaceous cuttings can be taken throughout the growing season (spring to late fall), while softwood cuttings should be taken in spring or early summer. Cuttings can be taken as long as the parent plant is healthy and in active growth.
It is recommended maintaining the relative humidity in a propagation house at a minimum of 85 percent. This can be done with mist or fog systems.
All cuttings need to go directly to an environment with 100% humidity after being cut. If the cuttings dry out, they will not do well. Keep them dark, cool and moist. If you are working in large areas, use wet cheesecloth or burlap to wrap the cuttings as you go along.
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.
Most plants will not root well in full sun, so place the cuttings in a location where they will receive a 50/50 ratio of shade to dappled sunlight. For most plants, cuttings thrive on warmth and humidity, and the growing medium should be kept evenly moist but not drenched while roots develop.
In general, the rooting medium should be sterile, low in fertility, drain well enough to provide oxygen, and retain enough moisture to prevent water stress.
With cuttings in transit, you don't need to worry about it until after a week. It'll most likely be ok, if not totally fine. As for forgotten cuttings, you've probably got a good few days, depending on where it is.
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.
Some plants will root in water, but cuttings will develop a better root system when rooted in a soil-less potting mix. Sand or perlite can also be used, especially for cuttings that need good drainage and may rot if kept too wet.
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.
For plant roots to grow faster, it requires nutrients, sufficient water, well-aerated soil, enough light, the right range of temperature and proper amendments. Nitrogen, phosphorus and potassium are the three essential nutrients that a plant requires for its growth.
If you want to keep your plant small, you can accomplish this by trimming the roots, but it's quite an exact science, and if you do it for a long time, you can damage the plant and risk killing it. However, a quick trim because your plant is super root bound and you don't currently have another pot is fine, but tricky.