Trimming rose of sharon is a simple process that can be done to improve the appearance of your plant. By trimming off the dead or diseased leaves, you will allow the plant to focus its energy on new growth. This will also help to improve air circulation around the plant, which can help to prevent fungal diseases.
Related plant:
Trimming Holly Bushes
Related plant:
Trimming Overgrown Evergreen Bushes
About soil condition, the rose of sharon prefers well-drained soil that is high in organic matter. The soil should be moist but not wet. If the soil is too wet, the roots will rot. If the soil is too dry, the plant will not be able to absorb enough water.
Just like other members of the hibiscus family, rose of sharon requires full sun to produce the most flowers. It will grow and bloom in partial sun, but the overall plant size may be smaller and the number of flowers reduced. You can expect rose of sharon to flower from mid-summer to early fall when little else is in bloom.
The temperature condition for rose of sharon is important. If it is too hot, the rose of sharon will not bloom. If it is too cold, the rose of sharon will not bloom. The ideal temperature condition for rose of sharon is between 70-80 degrees Fahrenheit.
Ideal humidity condition for this plant is 50% or below. Plants grown in higher humidity are more likely to suffer from foliar diseases, such as powdery mildew and gray mold. If you live in an area with high humidity, you can still grow rose of sharon, but you'll need to take extra care to keep the plant healthy.
The fertilizer, this family of plant foods provides essential nutrients to promote healthy growth in plants, including roses of sharon. The three primary nutrients found in fertilizer are nitrogen, phosphorus, and potassium (often referred to as NPK). Nitrogen is responsible for leaf growth, phosphorus promotes root development, and potassium strengthens the overall plant.
Pruning your rose of sharon helps to ensure that it remains healthy and blooms abundantly. While the plant can tolerate some pruning, it is best to prune it back hard every few years to encourage new growth. When pruning, be sure to remove any dead or diseased wood, as well as any branches that are crossing or rubbing against each other.
Propagation is usually done by rooting stem cuttings taken from the desired plant. The cuttings should be taken from new growth and be at least 4 inches long. Cuttings should be taken from the desired plant in late spring or early summer. The bottom leaves of the cutting should be removed, and the cutting should be placed in a pot filled with moistened potting mix. The pot should be placed in a location with bright, indirect light. Keep the potting mix moist but not soggy. Once the cutting has rooted, it can be transplanted to a larger pot or outdoor garden.
Usually, the plant growth rate is rapid during the first 2 to 3 years after planting. After that, the rate slows some but is still fast for another 2 to 3 years. Then, it slows even more and levels off. Some varieties, such as 'Dazzle' and 'Fancy Feathers', continue to produce new growth even after 20 years.
Common problems for this kind of plant are listed below. If you have any of these problems, consult a professional before attempting to trim your plant. -The plant is too tall and is in danger of toppling over. -The plant has become so leggy that it no longer has a pleasing shape. -The plant is producing few or no flowers. -The plant is infested with pests or diseases.
Source:
Hibiscus syriacus (Hibiscus, Rose of China, Rose of Sharon, Rose
Guide to Pruning Roses | University of Maryland Extension - UMD
Althea (Rose of Sharon) | Texas Plant Disease Handbook
