Plant Selection and Display
In more recent years we have found that retailers are experiencing greater difficulties in maintaining healthy stock of Calluna varieties on their sales benches due to foliar browning and dieback. This can be due to wetter Summers or conversely increased irrigation requirements in drier years.
This is mainly due to fungal infection which gains a hold where the plants kept in an environment that is unnatural to their requirements. Calluna cultivars generally require an open sunny situation, well-drained root area and dry or well-ventilated foliage.
The market demand for a pot full of bushy dense foliage coupled with daily summer irrigation regimes providing excess water and moist humid air does nothing to aid the plants well-being for survival. To keep the plants at their best the only way forward is to utilise regular control sprays.
Here at Forest Edge, as with most other heather growers, we utilise a routine control programme ensuring that only healthy stock leaves the nursery. However we appreciate that this is not a method that retailers can always maintain.
We are therefore reducing the quantity of our Calluna production and increasing the numbers of alternative species such as Daboecia, Erica Cinerea, Tetralix and Williamsii which provide for attractive extended flowering and foliage potential for summer sales.
Situation of the Sales Area
A light open airy situation is best where air movement can keep the plants well ventilated. Site plants on a bench preferably at waist height with taller plants at the back or centre of the bench. Remember that customers’ arms do not extend very far.
Avoid a site where the bench is shaded as this will encourage plants to lose their colour. A shaded bench is often in a damp airless situation that encourages the growth of fungal diseases. It is most important that the bench should be regularly (at least once a year) drenched with a horticultural disinfectant to prevent the build up of fungal pathogens.
It is essential that the compost of heathers is kept moist. They will not tolerate drought, which is the visible wilting of the young shoots followed by death of the branch tips and subsequent death of the whole plant.
Over-watering will result in airless compost, encouraging the growth of pathogenic fungal diseases in the compost causing root and stems to die. The symptoms can be similar to drought in severe cases but can also be the initial cause of fungal infection gaining a hold at soil level and causing browning of the basal foliage spreading upwards throughout the plant.
Prior to watering feel the compost to see whether watering is necessary. Do not apply if the compost is already moist. If in doubt take the pots off some of the plants and inspect the compost to assess water requirement. Apply water in regular small quantities rather than drenching excessively occasionally.
Excessive application of water with a high PH (lime content) will place plants under stress and cause early deterioration of summer flowering varieties.
Heathers benefit from a regular fungicidal application to avoid or control foliage browning. A routine application at two week intervals should suffice throughout late Spring, Summer and early Autumn. Alternate or vary the type of fungicide to be applied to avoid build up of resistance and ensure that the spray penetrates throughout the plant. Contact your heather supplier for further up to date information.
Plants on the sales bench should be spaced so that the foliage of one plant is barely touching its neighbour. Young plants may be displayed pot thick in trays but remember to space as they grow.
To keep the plants looking at their best trim off dead flowers to the base of the flowering spike.