Crabapple trees, with vibrant spring blossoms, colorful autumn fruits, and attractive form, are a delightful landscape addition. Propagating them allows gardeners to expand collections, share varieties, or preserve a favorite specimen’s unique characteristics.
Propagating from Seeds
Propagating crabapples from seeds begins by collecting ripe fruits in late summer or early autumn. Remove the fleshy pulp from the seeds by crushing the fruit and rinsing them under running water. Cleaning prevents mold and fungal growth during stratification.
Crabapple seeds require cold, moist stratification to break dormancy for germination, mimicking winter conditions. Place the cleaned seeds in a moist medium, such as peat moss or sand, in a sealed plastic bag or container. Refrigerate them at 35-40°F (1-4°C) for 60 to 90 days.
After stratification, sow the seeds in early spring in well-draining potting mix, about 1/4 to 1/2 inch deep. Maintain consistent moisture and indirect light for germination, taking several weeks. Trees grown from seed may not exhibit the exact characteristics of the parent plant due to genetic recombination.
Propagating from Cuttings
Cuttings produce a clone, genetically identical to the parent tree. Softwood cuttings, taken from new growth in late spring to early summer, are the most successful. Select healthy, non-flowering shoots that are about 6 to 8 inches long and have at least three to four nodes.
Make a clean cut just below a node, and remove the leaves from the lower half of the cutting to expose rooting sites, preventing moisture loss. Dipping the cut end into a rooting hormone, specifically one containing indole-3-butyric acid (IBA), enhances root development. It stimulates cell division and root initiation.
Insert the prepared cuttings into a well-draining rooting medium, such as perlite and peat moss, ensuring at least one node is buried. Create a humid environment by covering them with a clear plastic dome or bag, and place them in a location with bright, indirect light. Maintaining consistent moisture and warmth, around 70-75°F (21-24°C), encourages root formation, which occurs in several weeks to a few months.
Propagating by Grafting
Grafting joins a desired crabapple variety (scion) onto a rootstock, ensuring the new tree possesses the scion’s specific traits. This method controls mature tree size, achieves faster fruit production, or propagates specific cultivars that may not grow true from seed. Grafting success relies on precise alignment and union of the cambium layers (growth tissue just beneath the bark) of both the scion and rootstock.
Select dormant scion wood from the desired crabapple variety in late winter or early spring, ensuring health and disease-free status. Rootstocks are chosen for their disease resistance, hardiness, or dwarfing characteristics. Common grafting techniques for crabapples include whip-and-tongue grafts for young, similarly sized wood, or cleft grafts for joining a smaller scion to a larger rootstock.
During grafting, make clean, precise cuts on both the scion and rootstock for maximum cambium contact. Secure the union tightly with grafting tape or parafilm to hold them and prevent desiccation. After grafting, apply a grafting wax or sealant to cover all cut surfaces, protecting against moisture loss and pathogens.
Caring for Young Crabapple Trees
Consistent care promotes healthy development once crabapple seedlings, rooted cuttings, or grafted plants establish. Provide young plants with adequate moisture, watering regularly to keep soil damp but not waterlogged, especially during dry periods. Ensure sufficient sunlight (at least six hours daily) for robust growth.
Monitor young crabapple trees for pests and diseases, addressing issues promptly with appropriate treatments. Apply a balanced, slow-release fertilizer in spring to support initial growth, but avoid over-fertilization, which can harm tender roots. As young trees mature and develop a strong root system, transplant them to their permanent location, ideally during their dormant season.