How to grow Greenhouse Carnations

Perpetual Flowering Carnations (The Greenhouse Carnation)

Plant in a good free draining compost, we use Arthur Bowers Multi-Purpose potting compost for all our potted plants. Place the plants in a sunny position, they can cope with heat and as much light as possible. While they are still small keep them frost free - this is a precaution more than a requirement.

Well rooted cuttings should be potted into 3½" (9cm) pots, then moved up to a 6" (15cm) pots, in which they can remain. As the plant grows it will require supporting, Allwoods Plant Supports No. 2 are ideal for this. Make sure each plant has good air circulation and plenty of light as this is essential for good growth and healthy plants.

Stopping: As the plant grows you need to encourage it to bush out with new side shoots. To do this we carry out ‘stopping’. This means the removal of the growing tip of the young plant. (Plants left unstopped would produce a tall single stem without any side growth and will only prouduce the one flower at the tip. By making the plant bush, you get a more attractive looking plant and also more flowers.) To do this simply bend the growing tip sideways until it snaps, usually best done early in the day and you will find the plant snaps out easier. Normally plants supplied will have had their first ‘stop’ on our nursery. Where to ‘stop’ them is entirely your choice - bear in mind, where you stop the plant is where it will shoot from. Usually by keeping it quite short, about 6" from pot level, you will find this is a manageable height. Once the plant is nice and bushy looking you can leave shoots to grow up into flower. By ‘stopping’ one or two shoots each time, you can stagger the flowering production and ensure continuous blooms. Plants left unstopped will flower earlier, but will produce less blooms. Flowers can reach heights of between 1 to 3 feet.

Watering & Feeding: Watering needs to be done on a regular basis to maintain a moist but NOT wet compost. Feeding should commence soon after potting into larger pots and continue throughout the season. Our balaced plant food is ideal for this or alternatively a general liquid feed such as Phostrogen is satisfactory.

Flowers: When the flower bud develops, other buds will form lower down the stem and these should be removed, as the only bud required is the main one at the tip of each stem. They will grow happily in an unheated greenhouse, but if you want flowers all year round then a heated greenhouse during the winter months is required. Maintain a temperature of 7ºC (45F), please note winter flowers are less abundant due to the low light levels. When flowers are finished, dead-head and remove the stem down to near the base of the plant. This will keep it at an ideal height and be more manageable, if left the plant can quickly get out of control and reach heights of up to 6ft!


Further reading we recommend "How to grow Perpetual Carnations" booklet written by the British National Carnation Society, it can be found in our Gardening Aids section priced at £4.95.