It is always great to have an early Autumn surprise in the garden, particularly after the second dreadful summer in succession. Those who still talk of water shortages and the need for ‘dry’ gardens to counter the predicted hot dry summers should surely reconsider their views as global warming seems to be going to extemes with periods of volatile, unseasonal weather, instead. The sunshine of the last few weeks has encouraged plant I was not expecting to flower, to produce a beautiful cluster of blooms as usual, that should last well into October. Hedychium gardenerianum forms giant clumps in mild parts of Britain or warm temperate climates but is not hardy in Hertfordshire so I grow it in a pot of peat substitute compost and over-winter it in a frost free greenhouse. As the image shows, this plant certainly creates the ‘tropical’ look. Named for Edward Gardner, a collector or Botanical Specimens for Calcutta Botanic Gardens and the East India Company’s resident in the Nepalese Court from 1816-29, it is a native to the Himalayas in Nepal, Sikkim to Assam growing at altitudes up to 6600 feet. In certain parts of the world like New Zealand and the Azores, it has become an invasive weed – I wonder how we would have felt if this had been planted instead of ‘Japanese Knotweed’?
Other hardier gingers like the cultvars of Hedychium densiflorum create an attractive show, too, even though the flowers are not as large. A selection from the first ever plants to be introduced into Britain was tried outdoors in the 1970’s after decades of glasshouse cultivation, found to be hardy and named ’Assam Orange’ it is a fabulous plant though not as gorgeous as the cultivar ‘Sorung’ which is a soft apricot pink. Try them permanently outdoors in a sheltered spot in dappled shade in organic rich soil and mulch over winter to protect the rhizomes from frost and plant in containers or keep them overwinter in a cool frost free place, planting them out once the danger of frost has passed then lift and store them indoors before the onset of cold winter weather. Water well if necessary when they are growing and feed in spring with slow release fertiliser, giving them a boost with liquid fertiliser later in the season, if required.
Don’t forget to check you greenhouse heater to make sure that it works before the cold nights set in. There is nothing worse than hearing predictions of frost and being unprepared. Having a roll of horticultural fleece available helps too, not only to protect tender plants outdoors but those in the greenhouse. I put some of my tender plants under the benches for added protection and make sure the compost has dried out too. Ventilate the greenhouse during sunny autumn days, shutting the windows by the middle of the afternoon to retain the warm air so it cools down slowly as the day draws on.
Remember to cover your pond before the leaves start to fall in great numbers. Spread fine netting over the surface to prevent smaller leaves from getting through – netting used to cover raspberries and other fruit crops is ideal and gives it a dual use in the garden. Happy gardening!