Propagating crepe myrtles from cuttings is one of the most rewarding gardening skills you can develop. Not only does it allow you to create exact genetic copies of your favourite trees, but it's also surprisingly straightforward once you understand the basics. Whether you want to share a beloved variety with friends, create a matching hedge, or simply enjoy the satisfaction of growing your own trees from scratch, propagation opens up exciting possibilities.
Crepe myrtles root readily from cuttings compared to many other ornamental trees, making them an excellent choice for gardeners new to propagation. With the right timing, materials, and care, you can achieve success rates of 70-90% even on your first attempt. This comprehensive guide walks you through every step of the process, from selecting cutting material to caring for your newly rooted plants.
Best Time to Take Cuttings
Timing significantly affects your success rate when propagating crepe myrtles. In Australia, you have two primary windows for taking cuttings, each with distinct advantages.
Softwood cuttings are taken in late spring to early summer (October to December) when new growth is still green and flexible but beginning to firm up at the base. This is generally considered the easiest method with the highest success rate. The stems should bend without snapping but feel slightly woody at the lower portion. Softwood cuttings root quickly, often within three to six weeks, but require more attention to prevent wilting during the rooting period.
Hardwood cuttings are taken during winter dormancy (June to August) when trees have dropped their leaves. These pencil-thick stem sections are more forgiving of neglect and don't wilt like softwood cuttings, but they take considerably longer to root, sometimes three to four months. Hardwood cuttings are ideal if you can't provide constant attention or lack propagation facilities like misting systems.
Semi-hardwood cuttings, taken in late summer to early autumn (February to April), offer a middle ground. The current season's growth has matured enough to resist wilting but still contains enough active growing tissue to root relatively quickly. Many professional propagators prefer this timing for consistent results.
Cutting Type Comparison
- Softwood (Oct-Dec): Fastest rooting (3-6 weeks), highest success rate, requires most care
- Semi-hardwood (Feb-Apr): Moderate rooting time (6-10 weeks), good success, easier care
- Hardwood (Jun-Aug): Slowest rooting (3-4 months), lower success, minimal care needed
Materials You Will Need
Gathering your materials before starting ensures the process goes smoothly and cuttings don't sit out drying while you search for supplies. Here's what you'll need for successful crepe myrtle propagation.
Sharp, clean secateurs or pruning shears are essential for making clean cuts that heal quickly and resist infection. Dull blades crush stems, damaging tissue and reducing rooting success. Sterilise your cutting tools with methylated spirits or a dilute bleach solution between different trees to prevent spreading any diseases.
A quality propagating mix provides the ideal balance of moisture retention and drainage. Commercial seed-raising or propagation mixes work well, or create your own by combining equal parts perlite and peat moss (or coco coir as a sustainable alternative). Avoid standard potting mix, which holds too much moisture and can cause cuttings to rot before rooting.
Rooting hormone powder or gel significantly improves success rates, particularly for hardwood cuttings. Products containing IBA (indolebutyric acid) at 0.1-0.3% concentration suit crepe myrtles well. Dip the cut end in hormone before planting, tapping off excess powder to prevent fungal issues.
Small pots or propagation trays with drainage holes contain your cuttings during rooting. Tubes or individual cells work better than community trays as they minimise root disturbance when transplanting. Clear plastic bags or propagation domes maintain humidity around softwood cuttings. A spray bottle for misting and labels to track varieties and dates complete your kit.
Taking and Preparing Cuttings
Select cutting material from healthy, disease-free trees showing vigorous growth. Avoid stems with pest damage, discolouration, or signs of stress. The best cuttings come from the current season's growth on younger branches rather than old, woody stems near the trunk.
For softwood and semi-hardwood cuttings, select stems 10-15cm long with several leaf nodes. Make a clean cut just below a node (the bump where leaves attach), as this area contains concentrated growth hormones that encourage rooting. Remove leaves from the lower half of the cutting, keeping two or three leaves at the top. If remaining leaves are large, cut them in half to reduce moisture loss through transpiration.
For hardwood cuttings, select pencil-thick dormant stems 15-20cm long. Make a straight cut at the bottom and an angled cut at the top so you can remember which end is up when planting. Some propagators wound hardwood cuttings by scraping a thin layer of bark from the bottom inch to expose more cambium tissue and encourage rooting.
Key Takeaway
Take more cuttings than you need, as not all will root successfully. A 70-80% success rate is excellent, so if you want ten new plants, take fifteen cuttings to account for losses.
Planting and Care During Rooting
Fill your containers with moistened propagating mix, firming it gently to eliminate air pockets. Use a pencil or dibber to create planting holes slightly larger than your cutting diameter, preventing rooting hormone from scraping off as you insert the stem.
Dip the bottom 2-3cm of each cutting in rooting hormone, shake off excess, and insert into the prepared hole. Firm the mix gently around the cutting to ensure good contact. Space cuttings so leaves don't overlap, allowing air circulation that reduces fungal problems. Water lightly to settle the mix around stems.
For softwood cuttings, maintaining high humidity is critical during the first few weeks. Cover containers with clear plastic bags supported by stakes to keep plastic off the foliage, or use propagation domes. Place in bright, indirect light rather than direct sun, which can overheat enclosed cuttings. Open covers briefly each day to provide fresh air and check moisture levels.
Hardwood cuttings need less intensive care. Keep them in a sheltered position outdoors, protected from extreme cold and direct summer sun. Water only when the top centimetre of mix dries out. Patience is essential as roots develop slowly during the cooler months.
Bottom heat from heat mats designed for propagation accelerates rooting for all cutting types. Maintaining soil temperature around 20-25°C encourages root growth while cooler air temperatures reduce moisture loss from leaves. This approach is particularly valuable for early-season softwood cuttings when ambient temperatures remain cool.
Signs of Rooting and Transplanting
Checking for root development requires patience and gentle handling. After the expected rooting period for your cutting type, look for signs that suggest success. New leaf growth from the stem tip is the most obvious indicator, though some cuttings produce leaves before developing adequate roots for transplanting.
Gently tug the cutting, feeling for resistance that indicates roots have formed. If the cutting pulls out easily with no root development, replant it and continue care. Softwood cuttings may root in as few as three weeks under ideal conditions, while hardwood cuttings typically require the full dormant season before showing significant root development.
Once roots are 2-5cm long, cuttings are ready for potting into larger containers with standard potting mix. Handle transplants carefully, as new roots are fragile and easily damaged. Water well after transplanting and keep in a sheltered position for several weeks while plants establish in their new containers.
Hardening Off New Plants
Rooted cuttings grown under covers need gradual exposure to outdoor conditions before planting out. Increase ventilation over two weeks, then move plants to a sheltered outdoor position for another two weeks before planting in their permanent location. This process prevents transplant shock and leaf burn.
Common Problems and Solutions
Even experienced propagators encounter setbacks. Understanding common problems helps you diagnose issues early and adjust your technique for better results.
Wilting cuttings indicate insufficient humidity or excessive heat. Move containers to a cooler position and ensure humidity covers are properly sealed. Misting more frequently can help, but avoid waterlogging the propagation medium. Remove any cuttings that collapse completely, as they're unlikely to recover and may harbour fungal spores.
Black, mushy stem bases indicate rot from excessive moisture or contaminated cuttings. Improve drainage by adding more perlite to your propagation mix and reduce watering frequency. Always take cuttings from healthy growth and sterilise tools between different parent plants.
Cuttings that remain green but never root may simply need more time, particularly hardwood cuttings taken late in the season. However, if softwood cuttings show no progress after eight weeks, they've likely failed. Try again with fresh material, perhaps adjusting your timing or rooting hormone strength.
Fungal growth on leaves or the medium surface suggests poor air circulation or excessive humidity. Remove affected cuttings immediately, improve ventilation, and consider applying a fungicide to remaining plants. A light dusting of cinnamon, a natural antifungal, on the medium surface can help prevent further issues.
Growing On Your New Trees
Successfully rooted cuttings need continued care to develop into strong, well-shaped trees ready for permanent planting. Pot rooted cuttings into progressively larger containers as their root systems develop, typically moving from tubes to 15cm pots to 20cm pots over the first growing season.
Begin light fertilising once new growth appears, using diluted liquid fertiliser at quarter strength every two weeks during the growing season. As plants establish, transition to slow-release fertiliser appropriate for flowering plants. Avoid over-fertilising young trees, which promotes weak, spindly growth.
Young crepe myrtles benefit from early training to establish good branch structure. Remove any crossing or inward-facing branches and encourage a strong central leader or multi-trunk form depending on your preference. Our pruning guide covers shaping techniques in detail.
Most propagated crepe myrtles can be planted in their permanent garden position after one to two growing seasons in containers. Choose your planting site carefully using our variety comparison tool to ensure you select a position that accommodates the mature size of your chosen variety. With patience and care, your home-propagated crepe myrtles will provide decades of beautiful summer blooms.