The third and last instalment of the Root Awakening column for Jan 2010 was published today.
The first question was about the growing of hibiscus plants from stem-cuttings. Hibiscus can be propagated via both softwood and semi-hardwood stem-cuttings. Softwood cuttings are taken from soft, succulent, new growth. Shoots are suitable for making softwood cuttings when they can be snapped easily when bent and when they still have a gradation of leaf size (oldest leaves are mature while newest leaves are still small). They usually root faster than semi-hardwood cuttings.
Semi-hardwood cuttings refer to stems taken from partially mature wood. Such stems are reasonably firm, the leaves of mature size and may have some bark on them. Avoid material with flower buds if possible and remove any flowers and flower buds when preparing cuttings so the cutting’s energy can be used in producing new roots. Take cuttings from healthy and disease-free plants. Take stem-cuttings from plants that have been well-watered and do so in early morning when it is cooler.
Cuttings are best around 4 to 6 inches long by using a pair of sterilized sharp pruning shears. Remove the leaves from the lower one-third to one-half of the cutting. Cut large leaves in half to reduce water loss. Dip the cut end of a stem-cutting with some rooting hormone powder made into a slurry.
Stick stems into a new soil mixture that is sterile, low in fertility, and well-drained to provide sufficient aeration. Insert the cuttings one-third to one-half their length into the medium and maintain the vertical orientation of the stem. Cover the cuttings with a plastic bag and place in indirect light. Keep the medium moist until the cuttings have rooted. Rooting will be improved if the cuttings are misted on a regular basis.
Rooting time varies with the type of cutting, the species being rooted, and environmental conditions. Grow cuttings in a pot until they attain a larger size before transplanting to a permanent location.
The second question was about the shrivelling of leaves of a tree. It could be due to hot and dry weather. Under such weather conditions, it may be beneficial to ensure the plant is well-watered and roots are kept moist. Do also apply a layer of mulch around the root zone to ensure it stays moist and cool. If possible, provide some form of shade during this period. It could also be due to a bout of insect infestation and hence it would be necessary to check if there is any and ensure that all pest infestations have been cleared. Any remaining population can re-infest a plant if not properly eradicated. Several rounds of pesticide application may be necessary.
The last question was about the pruning of a money plant. A money plant will not die if its growing tip has been cut. The plant will respond by producing side shoots and this can take any time at least two weeks, depending on the growing conditions. Cutting back a money plant can be beneficial at times as it helps to keep a plant’s growth in check and can help to maintain or promote a bushier growth habit.