Topiaries, Hedges and Propagation

Over the last month I've learned about the shaping and training of plants and about the different propagation techniques they use in the nursery.  Most of the time, on the days I've been working with Eza and/or the nursery women, we are doing some sort of propagation or trimming.

Topiaries and shaping/training plants is a fairly common practice in Malaysia and is used in many landscapes and for indoor greenery designs. In the zoo, the main shaping/ training done is into either hedges, formal and informal, or spherical topiary shape. Additionally, they have a couple of topiary structures where the plants have been trained into unique shapes or letters. The plants most commonly used in the zoo are the bougainvillea, box woods, Euodia ridleyi, and ixora varieties.
For large leafed plants, such as the bougainvillea and ixora, hand shears are used to shape them into informal shrubs. Hand shears are used instead of trimming shears or power trimming devices to prevent the browning that occurs when leaves are partially cut. When doing the formal shrubs smaller leafed plants are used like boxwood, and trimming shears or power trimming devices are used due to the small surface area of the leaves so if they are cut then the browning isn’t really evident.

Bougainvillea before

The boxwood and Euodia ridleyi are also used for topiaries. Depending on the degree of detail of the topiary they are either shaped by hand or by using a cage structure in the shape of the desired design. When doing sphereical topiary designs we used Euodia ridleyi and eyeballed the shape using hand shears for the trimming. The boxwood has a sturdier structure and is used for the more complicated designs and for the upright lettering.

The propagation that I've been involved in has been from dividing roots, and from taking cuttings. The propragation by root division was used often for the 51 varieties Zoo Negara has of Heliconias and for bamboo and ginger. The root divisions were mostly done when redoing the landscaping of an area and the old plants were removed and brought back to the nursery for repotting.

Bougainvillea after shaping

When doing the repotting, we would trim back the greenery and split the roots around where new plant growths were growing from the root system, using a machete, before placing into individual pots. For the propagation by cuttings, most of the cuttings are taken when doing the trimming and clean-up of the plants. After which, we took the trimmings to the potting area. Many of the plants I've worked with are runners, so when they’re clustered together they naturally expand into each other's pots during growth. The trimmings from these have root growth along the stems, and we cut below the roots along the stems and place them directly into new soil. For the trimmings that weren’t from runners, and didn’t have root growth on them, they were placed into liquid root stimulator for 15 minutes and then placed into the new soil.