Apple trees generally have a lifespan of 25 to 50 years. While apple varieties have slightly different growth patterns, their growth timelines are identical.
Most apples are grafted to ensure high-quality fruits, but you can grow an apple tree from seed and use it as a beautiful ornamental tree.
Growing an apple from seed to a mature tree takes years but is a rewarding experience. Experts and home gardeners need to know the growth stages of the apple tree to contend with insects and diseases.
Germination
Seeds germinate around 60 to 90 days, depending on type and soil. The seed contains two large seed leaves and a thin layer of nutritious endosperm.
Damp, chilly weather is required for apple seeds to germinate. The radicle emerges first, anchoring the seedling and absorbing water and nutrients. Afterward, the round and fleshy seed leaves emerge at the stem’s tip, opposite one another.
The true leaves will appear after a couple of days. The apical stem grows between the two cotyledons, giving rise to elongated, oval true leaves with jagged edges. Until plants can produce their food through photosynthesis, the stored nutrients in the cotyledons help with seedling development.
Juvenile
The juvenile phase can span anywhere from three to 10 years, depending on the variety and cultural practices used. The young plant will resemble a thorny bush. During this period, the roots are also quickly growing.
The apple seedlings will begin rapid vegetative development once transplanted. The leaves and stems of young plants are smaller and finely serrated. When the plants mature, they produce larger dark green, ovate leaves. The leaf edges are curved and serrated.
The plant will respond to flowering signals as they mature. They generally bloom annually or biennially.
Flowering
The emergence of flower buds signifies the beginning of the plant’s mature stage. There is a transition time in which the bottom section of the plant is still a juvenile, and the top section is mature.
When the weather warms up in the spring, the dormant buds bloom, the buds first have silver, fluffy tissue before developing a green tip.
As the flower buds grow, they are surrounded by five green, hairy sepals. The white-pink flowers will fully open after a while. Bees travel from flower to flower, collecting pollen from anthers. The pollen they carry when they visit other trees rubs off on the flowers.
When pollen is released from flowers, the petals droop, and the anthers shrivel. The stigma enables pollen to reach the ovary so the fruit can form.
Once the tree has been fertilized, the tree’s petals will start to fall off. As the ovary expands, the flared sepals grow upright, and the stamens wither and dry up.
Below the sepals, the fuzzy apple begins to grow.
Fruiting
Apples develop into fruits from the base of the flower after pollination and fertilization. The flower walls that enclose the seed chamber form the fruit’s flesh. A few weeks later, the fine hairs on the developing apple disappear.
Apple seeds develop within the flower’s ovary, surrounded by a fleshy wall that transforms into a fruit. A large number of cells is necessary for good fruit size. The four stages of apple fruit growth include cell division, cell expansion, maturation, and ripening.
Cell division, a critical stage, occurs only in the first few weeks after flowering. The fruit swells via cell expansion in the next three to four weeks. The cells absorb a lot of starch, and the fruit will increase in size. Growing fruits start to store sugar, grow in size, turn green, and eventually turn red as they ripen.
The ripening process is triggered by ethylene, a natural hormone in plants. Generally, there is a 7 to 11-day window for picking high-quality fruit.
The apple tree will continue to bloom and bear fruit throughout its mature phase if cared for properly.
