Posted on | October 25, 2008 | 1 Comment
Sadly, the end of the season has finally arrived here at the Exotic Garden with tomorrow afternoon’s opening being the last of 2008.
It was only a few years ago that I decided to keep the garden open until the end of October at the request of friends and visitors, and it was only five years ago that the garden was open every other weekend until the end of September. How things have changed.
Despite the distinct lack of warming sun this year, the garden has fared well, especially with all the rain we’ve had in recent months prompting much growth, particularly this month. In fact, autumn is one of the best times to see the garden in all its glory.
Many plants, such as the Brugmansias (Angels Trumpets) flower until the first frosts of autumn hailing the beginning of their forced dormancy. Specimens that were planted in the ground in late May will soon have to be dug up and over-wintered in large black plastic pots with much of their root system removed. They can be stored at any height as long as you have the room.
I prune mine back to about 7ft so that they fit comfortably in the conservatory. Equally, they can be cut back severely to within a few inches of the ground and put under a bench in a greenhouse or shed, where they do not need light as they will be dormant until the spring.
Container grown plants can be kept in bloom over winter at a temperature of 10C (50F) and higher if you have somewhere light to keep them going, otherwise a few degrees above freezing is adequate as long as they are kept on the dry side. I loathe having to put the garden to bed at this time of year as it is still so full of vitality, with many plants such as the bananas looking at their best and most vigorous, especially the purple Abyssinian banana Ensete ventricosum ‘maurelli’.
This fabulous banana is native to the Ethiopian plateaus where it enjoys cool weather though it is damaged by the slightest frost, unlike the much harder Musa basjoo which has been growing outside at the Exotic Garden for over two decades with – as yet – no loses.
Until five years ago the basjoos were surrounded in November by wooden pallets up to 3m (10ft) high, but now, due to much warmer winters and laziness on my part, they are left to the vagaries of our temperate winters. The heat-loving purple Abyssinian bananas do have to be over-wintered though if you wish to have even bigger specimens the following year.
This will be done here in the first week of November before the first frosts. Many, being very large now, require at least two people to dig up these colossal plants. Several have reached 3.5m (12ft) high this year with trunks up to 30cm (1ft) across. Hence, they’re very heavy. Most of the top growth is removed, leaving trunks up to 1.5m (5ft) high. The ground around them is sliced through, about 5-8cm (2-3ins) away from the trunk, and the root ball is then placed in large black plastic pot or dustbin liner.
Don’t worry about cutting so many roots off, these will re-grow next year This can be a messy job as, being so full of water, they tend to leak all over the place. The heavy trunks are then man-handled into a greenhouse where they are over-wintered at a minimum of 10C (50F). Smaller plants can be over-wintered in a cool bedroom if you do not have a greenhouse or conservatory.
Many of the so-called house plants that are grown in the garden are treated as throw-away plants because I don’t have room to store all of them through the winter. Thus, leaving them in the garden is a good chance to test if they have any hardiness. I have mentioned before that the supposedly non-hardy houseplant Tradescantia fluminensis (Wandering Jew) has been left outside through six winters now, where they grow as herbaceous perennials that re-emerge in April. The Spider plant Chlorophytum comosum is also a returning perennial at the Exotic Garden, dying back to a central tuft, to return with full vigour the following spring.
One set of houseplants that do have to be brought under cover are the bromeliads. These fabulous plants are over-wintered in a polythene tunnel at around 5C (40F) and warmer if possible.
The more tender forms go into a large propagating frame and are overwintered at around 15C (59F), keeping them nice and cosy on the coldest nights. Most of the cannas are left in position to enjoy the dwindling autumn sun until they are blackened by frost, usually in December, though in some years it has been Christmas before this has happened. They are then cut down to within 6in of the ground and the foliage placed over the crowns to keep the tubers from freezing.
Many of the gingers are hardy and can stay in the ground throughout the winter with a mulch of straw or something similar that will protect their crowns from the worst of whatever the winter throws at them. If you have wet, clay soil I would recommend potting them up for the winter and storing them in an out-house or under a greenhouse bench and keeping them on the dry side.
Many of the succulents, cacti and other spiky things will, in fact, take extremely low freezing temperatures well as long as water doesn’t collect in their crowns, thus causing rot in the damp days of mid-winter, and as long as they are planted in extremely well-drained sandy soil. If in doubt a temporary greenhouse can be made over them using horticultural polythene to keep out the worst winter weather.
For now, though, don’t forget that tomorrow’s your last chance to visit the Exotic Garden this year, unless, that is, you are one of the many volunteers who help out during winter.
The garden still boasts luxuriant growth and colour, so why not come along and have a final stroll through the garden before it goes into its winter slumber.
Meanwhile, have a good winter and enjoy reading those seed and plant catalogues!