HIBISCUS
Hibiscus are a huge and varied family containing 300 species of hardy and tender annuals, evergreens and deciduous shrubs. Of these, three tender evergreen are in general cultivation, but in Great Britain they will require protection so should be treated as houseplants.
Native to much of Asia, hardy hibiscus has been been grown as a garden shrub in Korea since time immemorial. In fact, it has become the national flower of South Korea where its flowers are eaten and the leaves are brewed for a tisane - whatever that is (fancy herbal tea apparently)!
For general hardiness, the strongest species is Hibiscus syriacus and luckily for gardeners, this species comes in at least a couple of dozen colour forms. These include double flowered forms as well as some varieties which display variegated leaves!
How to grow the hardy Hibiscus
Hibiscus syriacus and its numerous varieties will thrive in any well drained, fertile soil. Fertile is the key here as this species is incredibly hungry. Even the spring new growth will emerge looking nitrogen deficient so regularly top dress with a rich compost. Failing that, give them a regular liquid feed.
If your hibiscus plant is container grow then it can be planted at ant time, just be aware that you will need to keep an eye on the watering if you decide to plant during the height of summer.
Plant in a sheltered border, but make sure that it is in a position that takes full advantage of the sun. As hardy hibiscus are late flowering, it is advisable to protect them further by growing them against a wall or the side of a house in northern gardens.
Once established, there is no need to prune your hardy hibiscus, but long shoots can be trimmed back after flowering.
Be aware that drought conditions and low night temperatures can cause bud drop
Propagation
Hibiscus are easily grown from seed, in fact you will normally see hundreds germinating in the spring beneath the parent plant. However, these seedlings are unlikely to grow true to the parent plant, so you will need to propagate hibiscus as cuttings in the summer to ensure that you grow the same cultivar as the parent plant.
The next step before potting is to apply a rooting hormone in powder, liquid or gel form. This step is optional but, if used, will promote earlier root initiation and a more vigorous root growth. The cuttings are then placed in individual propagating tubes or small pots.
Place your hibiscus cuttings in the shadehouse to protect them from wind and to prevent their drying out. Cuttings will root quite well in coarse river sand but the risk of this drying out is high and it is safer to add a little peat or perlite to the medium to hold moisture. However, various mixtures of perlite, peat and perlite, peat and sand, etc., have all been successful.
Once the cuttings have struck, they can be potted on into larger pots using a good quality potting mix.
Hibiscus are a huge and varied family containing 300 species of hardy and tender annuals, evergreens and deciduous shrubs. Of these, three tender evergreen are in general cultivation, but in Great Britain they will require protection so should be treated as houseplants. Native to much of Asia, hardy hibiscus has been been grown as a garden shrub in Korea since time immemorial. In fact, it has become the national flower of South Korea where its flowers are eaten and the leaves are brewed for a tisane - whatever that is (fancy herbal tea apparently)!
For general hardiness, the strongest species is Hibiscus syriacus and luckily for gardeners, this species comes in at least a couple of dozen colour forms. These include double flowered forms as well as some varieties which display variegated leaves!
How to grow the hardy Hibiscus
Hibiscus syriacus and its numerous varieties will thrive in any well drained, fertile soil. Fertile is the key here as this species is incredibly hungry. Even the spring new growth will emerge looking nitrogen deficient so regularly top dress with a rich compost. Failing that, give them a regular liquid feed.If your hibiscus plant is container grow then it can be planted at ant time, just be aware that you will need to keep an eye on the watering if you decide to plant during the height of summer.
Plant in a sheltered border, but make sure that it is in a position that takes full advantage of the sun. As hardy hibiscus are late flowering, it is advisable to protect them further by growing them against a wall or the side of a house in northern gardens.
Once established, there is no need to prune your hardy hibiscus, but long shoots can be trimmed back after flowering.
Be aware that drought conditions and low night temperatures can cause bud drop
Propagation
Hibiscus are easily grown from seed, in fact you will normally see hundreds germinating in the spring beneath the parent plant. However, these seedlings are unlikely to grow true to the parent plant, so you will need to propagate hibiscus as cuttings in the summer to ensure that you grow the same cultivar as the parent plant.
The next step before potting is to apply a rooting hormone in powder, liquid or gel form. This step is optional but, if used, will promote earlier root initiation and a more vigorous root growth. The cuttings are then placed in individual propagating tubes or small pots.Place your hibiscus cuttings in the shadehouse to protect them from wind and to prevent their drying out. Cuttings will root quite well in coarse river sand but the risk of this drying out is high and it is safer to add a little peat or perlite to the medium to hold moisture. However, various mixtures of perlite, peat and perlite, peat and sand, etc., have all been successful.
Once the cuttings have struck, they can be potted on into larger pots using a good quality potting mix.
