Hartley Magazine

All the latest news, hints, tips and advice from our experts

Hydrangeas are high-value plants for a greenhouse

When thinking of a new plant to grow in a greenhouse, it is easy to be completely overwhelmed by the wide range of choices available. 

Far more than any other gardener, greenhouse growers are totally spoilt for choice – and there are many reasons for this. 

The fact that a greenhouse grants a degree of control over the climate conditions the plants are exposed to is something of a boon, as a much wider variety of things can be grown. Being able to manipulate climate conditions means things can be grown that are not native to the region – and certain plants can even be nurtured out of their usual season. 

However, the hydrangea is one plant that offers value as a cut flower or potted plant – and it is ideal for greenhouse propagation. It can also be referred to as hortensia and is a genus of somewhere between 70 and 75 flowering plants. 

It is native to southern and eastern Asia and the Americas, but has long since become much more widely distributed all over the world. It is characterised by shrubs that can be anywhere between one and three meters tall – although some of the plants in the category are technically trees – and some lineas can reach up to 30 meters by climbing up other growths. 

The flowers of the hydrangea are produced over the course of a long summer – from early spring to late autumn. They grow in flowerheads at the end of stems – and two types of these can feature in many of the various species. 

Juergen Steininger, grower at Longwood Gardens in Kennett Square, Pennsylvania, argued that the hydrangea is underused – particularly as it has a great deal to offer as both a cut flower or potted plant. In an article for Greenhouse Grower, he noted that cut flower hydrangeas frequently stay in containers for several years, unlike the majority of standard pot crops. 

The expert underlined the importance of proper water management in order to make the most of hydrangeas. However, he added that the line between the ideal amount of water and too much is a very thin one. 

"At best, excessive water will lead to blind stems and flower bud abortion. Drip irrigation is preferred and avoid overhead irrigation," Mr Steininger suggested, adding: "Keep irrigation zones small to allow custom watering schedules. Make sure your containers are free-draining and have plenty of drainage holes." 

Andy Sturgeon, an acclaimed landscape and garden designer who has been awarded no less than six Gold Medals – as well as Best in Show – at the UK's prestigious Royal Horticultural Society Chelsea Flower Show, said that hydrangeas are ideal for brightening up a green space. 

"Most hydrangeas are essential garden plants as they flower for weeks and weeks and provide plenty of colour when not many other flowering shrubs are up to much," he stated in an article for UK national newspaper the Guardian. 

"If you have a dry soil, planting in a little shade is the best solution," Mr Sturgeon continued. "Hydrangeas hate being moved, though, so relocating isn't really an option."