Eucalyptus is widely recognized for its fast growth and fragrant, often glaucous (waxy, blue-green) foliage. The leaves release aromatic oils, making the plant useful for ornamental gardening and material harvesting. People commonly cut eucalyptus for two distinct reasons: to manage the plant’s size and maintain its health, or to obtain fresh or preserved stems for use in floral arrangements and crafts. Understanding the difference in technique for these two goals ensures both the plant’s survival and the quality of the harvested material.
Pruning Techniques for Plant Health and Shape
Horticultural cutting focuses on maintaining the health, structure, and desired size of the living tree or shrub. Cutting is divided into routine maintenance and aggressive size-control methods. Maintenance pruning involves removing dead, diseased, or poorly positioned branches that obstruct light and airflow within the canopy. Removing these branches helps prevent fungal diseases and promotes a robust structure.
For controlling the plant’s height and encouraging a dense, bushy form, gardeners employ specialized techniques such as coppicing or pollarding. Coppicing involves cutting the main stems back severely, usually to within 4 to 18 inches above the ground, before the active growing season. This stimulates the tree to produce numerous new shoots from the base, which typically bear the attractive, rounded, juvenile foliage preferred for decoration. Many eucalyptus species tolerate this severe cutting well due to a protective swelling at the base of the trunk called a lignotuber.
Pollarding is a similar size-control method, but the main trunk is cut back to a set height, often between six and ten feet, instead of near the ground. This technique forces new growth to sprout from the cut point, creating a head of foliage atop a clear trunk. This method is suitable for restricting the height of larger species in smaller spaces while maintaining a tree-like structure. The purpose is to manage the tree’s vigorous growth habit and encourage new, healthy growth.
Harvesting Stems for Display and Craft
Cutting eucalyptus stems for arrangements or drying requires selecting material based on quality, not the plant’s overall shape. Stems should be chosen when the foliage is mature, or “hardened.” This means the leaves feel firm and the stem is not soft or actively flushing with new growth. Mature stems hold up better after cutting and are less prone to wilting during preservation. Avoid stems showing signs of damage, discoloration, or pest activity.
The actual cut should be made cleanly and precisely to maximize the stem’s length while encouraging subsequent growth on the parent plant. Use sharp bypass pruners to make a slanting cut at a 45-degree angle. This angle increases the surface area for water uptake immediately after harvesting. The cut should be located just above a leaf node or an outward-pointing side shoot. Cutting above a node stimulates the dormant bud to grow, preventing a dead stub and promoting healthy branching.
When harvesting, do not remove too much material from any single area of the plant. Taking more than about one-third of the foliage at one time can exhaust the plant and stress its systems. Harvest selectively from throughout the plant to encourage even new growth and maintain the tree’s photosynthetic capacity. This careful approach ensures continued production and plant survival.
Essential Preparation and Optimal Timing
Proper preparation of tools and optimal timing are necessary for any cutting operation. All cutting implements, including pruners, loppers, and hand saws, must be kept sharp to ensure clean cuts that heal quickly. Sharp tools minimize stress and reduce the jagged tearing of plant tissue, which prevents entry points for pathogens and pests.
Sanitizing tools is equally important to prevent the transmission of diseases, as eucalyptus is susceptible to fungal issues. Use a simple solution of one part bleach to nine parts water, or a wipe with isopropyl alcohol, to disinfect blades before and after use. This safeguards the health of your collection, especially when moving between different plants.
The optimal time for heavy pruning, such as coppicing or pollarding, is generally in late winter or early spring, just before the plant breaks dormancy. Pruning during this dormant phase minimizes sap bleeding. It also allows the plant to use stored energy for vigorous new growth once the weather warms. Harvesting foliage can be more flexible, often extending into mid-summer when leaves are mature, but avoid cutting during extreme heat or freezing temperatures.
Post-Harvest Preservation Methods
Conditioning for Immediate Use
Once stems are removed, they should be quickly transferred to a bucket of water mixed with commercial floral food, a process known as conditioning. The stems benefit from being submerged in water for several hours in a cool, dark location before being arranged. This allows them to fully hydrate and reduces wilting.
Air-Drying
For long-term preservation, air-drying is a straightforward technique that allows the foliage to retain color and scent. To air-dry, secure small bundles of stems with a rubber band and hang them upside down. Use a location that is dark, dry, and has good air circulation, such as a cool basement or closet. Darkness helps prevent the rapid fading of the leaves’ color. The drying process typically takes between one and three weeks, depending on humidity and foliage maturity.
Glycerin Preservation
A more advanced preservation technique involves using a mixture of glycerin and water. This replaces the natural moisture in the leaves, maintaining their flexibility and natural appearance. A recommended solution is a ratio of one part liquid glycerin to two or three parts hot water, stirred until combined. Fresh-cut stems, with the bottom leaves removed, are placed directly into this solution for two to four weeks. As the glycerin is absorbed, it keeps the foliage pliable, which is useful for craft applications where stems need to be manipulated.