Hibiscus syriacus marina is a species of hibiscus native to China. It is a deciduous shrub growing to 25 m tall. The leaves are alternate, ovate to lanceolate, 1020 cm long and 58 cm broad. The flowers are white with purple veins, 58 cm diameter with 5-7 petals. The fruit is a dark brown capsule 58 cm diameter, containing numerous small seeds.
Related plant:
Hibiscus Blue Chiffon
About soil condition, Hibiscus syriacus marina liked the well-drained, moist, and slightly acidic soils with a pH of 6.0 to 7.0. They didn't like the chalky or alkaline soils. They also didn't like the very dry or waterlogged soils.
Just like other hibiscus syriacus, the Marina hibiscus need full sun to partial sun. Without enough sun, the plant will not bloom as often. The plant will also become leggy, with fewer leaves and branches. So, if you want your Marina hibiscus to look its best, make sure it gets plenty of sun.
The temperature conditions that are required for hibiscus syriacus marina to grow are not very specific. This plant can tolerate both hot and cold weather conditions. However, it should be protected from freezing temperatures. It prefers to grow in full sun or partial shade.
Ideal humidity condition for this plant is 50% or above. The Hibiscus Syriacus Marina doesn't do well in extremely dry or cold conditions. If the air is too dry, the leaves will become dry and start to fall off. If the temperature gets too cold, the leaves will turn brown and drop off.
Discussing fertilizer, this plant does best with a balanced fertilizer applied monthly. A nitrogen-heavy fertilizer will encourage lots of leaves at the expense of flowers. A phosphorus-heavy fertilizer will encourage lots of flowers at the expense of leaves. The best way to encourage both lots of leaves and flowers is to use a balanced fertilizer. Be careful not to over-fertilize, which can burn the roots.
Pruning is an important part of maintaining your hibiscus syriacus marina plant. While it's not necessary to prune every year, it's a good idea to do so every few years to keep the plant healthy and encourage new growth. When pruning, be sure to remove any dead or dying branches, as well as any branches that are crossing or rubbing against each other. This will help to keep the plant looking its best and prevent any potential damage.
Propagation of hibiscus syriacus marina is best done through softwood or semi-hardwood cuttings taken in late spring or early summer. The cuttings should be 4-6 inches long and taken from new growth. Cuttings should be placed in a well-draining rooting medium and kept moist until roots have formed. Once roots have formed, the newly rooted plants can be transplanted into individual pots or outdoors into the garden.
Usually, the plant growth rate during the vegetative stage is determined by the rate of cell division within the root, shoot, and leaves. While the average growth rate of the hibiscus syriacus marina is relatively fast, the maximum growth rate is determined by the environment and the amount of available resources. The average hibiscus syriacus marina plant will grow to be about 3 feet tall with a spread of 2-3 feet.
Common problems for this kind of plant are fungal diseases, such as powdery mildew and leaf spot. Other problems include aphids, scale, and whiteflies. These pests can be controlled with regular applications of insecticidal soap or horticultural oil.
Source:
Common Hibiscus (Hibiscus syriacus) UIC Heritage Garden
Hibiscus syriacus 'Variegata' - Oregon State University
Rose of Sharon - Hibiscus syriacus - PNW Plants
