Well it’s the middle of summer and there is no better time to consider adding a touch of the exotic to your garden because even a casual glance around your neighborhood will likely reveal a grove of hardy bananas, variegated canna lilies in full bloom or even the odd Passion Flower. Some of these tropical-looking plants are perfectly hardy, others are quite tender and need to be overwintered indoors, while many just require specialised protection to get them through the colder weather. Knowing your plant’s zone hardiness and seasonal appeal can be the difference between a successful tropical garden and one that has no aesthetic allure from late fall until early summer; so I am going to provide you with a few tips to point you in the right direction.
The Big Three
The bones of almost every tropical landscape include three plants; palms, bananas and bamboo. For truly hardy palms there are only two choices here, Chinese Windmill Palm or Trachycarpus fortunei (Z7) and the rare Chusan Windmill Palm ‘Wagnerianus’ (Z7). They get hardier with age, so I prefer palms that are at least 3’ tall before I commit from container to in-ground planting and if you can find those that have been seed-grown here in BC, even better. The reason for the latter is that quite often our palms are imported from California and these plants are not acclimated and easily lost in their first Canadian winter. The Japanese Fiber Banana or Musa basjoo (Z6) is an easy find here but many people forget that it will eventually form a multistem grove with quite a large spread. Another issue is overwintering, as the corm or root must be mulched to protect from frost and above ground stems insulated (using insulated sleeves) if you want to retain them and this can look a little ugly through the dormant season, so place these carefully. Mature stems will eventually bear a football-like flower and tiny bananas, after which it will die down but by that time it will be surrounded by younger pseudostems. The world of bamboo is vast, so I am going to stick to the basics. There are both running and clumping bamboos and the former need to be contained with a plastic barrier set in-ground to a minimum of 30”, otherwise your garden will transform into a bamboo forest in no time at all. Typical running bamboos include Black (Phyllostachys nigra Z7), Golden (Phyllostachys aurea Z7), Phyllostachys bissetii (Z6) and Yellow Groove (Phyllostachys aureosulcata (Z6) which can produce elegant zig-zag stems. All of these grow well in above-ground containers (think half-barrel size) if you are concerned about planting them. Clumping bamboos such as Fargesia require no containment as they spread only a few inches every year. Your best choices here are Fargesia rufa (Z6), Fargesia nitida ‘Jiuzhaigou’ (red stems Z5) and Fargesia robusta (Z7).
Fargesia robusta, Musa basjoo, Musa basjoo flower, Trachycarpus Wagnerianum
There are actually a lot of exotic-looking edibles that fit right into a tropical landscape and in my own garden I grow Golden Bay Laurel (Z8), Dwarf Pomegranate (Z7) with its flurry of bright reddish-orange late summer blooms and Chilean Guava (Ugni molinae Z8), although it is still in the process of recovering from last winter. Another of my favourites is the Contorted Hardy Orange (Poncirus trifoliata ‘Flying Dragon’ Z5) which has great fall colour and if you like lemons, keep an eye out for the self-fertile Yuzu (Citrus junos Z7) which can grow outdoors here. The variegated kiwi (Actinidia kolomikta Z4) with its attractive pink, white and green leaves and small edible fruits is a solid choice for vines, while any of the edible figs (Ficus carica Z6) already have that Mediterranean look. Last on my list is the hard to find Pineapple Guava (Acca sellowiana Z7-8) which needs a very long summer to produce fruit but whose edible flowers have an unusual cotton candy flavour.
Acca sellowiana, Actinidia kolomikta, Dwarf Pomegranate, Golden Bay Laurel, Poncirus Flying Dragon, Yuzu Hardy Lemon
Frost-tender exotics are a mainstay of the tropical landscape and many of these can be grown in large containers and overwintered in a small greenhouse (heated only when the temperature drops to below freezing) or cool sunroom. Angel Trumpets or Brugmansia (Z9) produce huge pendulous blooms of white (B. suaveolens), reddish-orange (B. sanguinea), pink (‘Frosty Pink’) and variegated peach (‘Peaches & Cream’), many of which are fragrant. Princess Flower or Tibouchina urvilleana (Z9) can provide tree-like proportions with large 3-4” wide deep purple blooms, while Flowering Maples (Abutilon x hybridum Z9) can also be trained into a standard form with pendulous flowers of almost any hue. Non-hardy vines or climbing shrubs such as Passiflora ‘Amethyst’ (Z8) or Bougainvillea (Z9) can be grown in large containers and trained to a mini-trellis to accommodate overwintering, but expect the latter to drop a lot of leaves when moved indoors. The black-leaved dahlias such as the Bishop Series provide a backdrop of jet foliage with a myriad of flower colour from June to October, with my favourite being ‘Bishop of Llandaff’. Last but not least are standard bedding plants with a truly tropical flare such as Osteospermum ‘Astra Purple Spoon’ which thrives in the cool of spring to early summer, while Joseph’s Coat (Amaranthus tricolor) will really come into its own in the heat with its lively red, green and yellow foliage.
Amaranthus tricolor, Bougainvillea Delta Dawn, Brugmansia Frosty Pink, Dahlia Bishop of Llandaff, Osteospermum Astra Purple Spoon, Passiflora Amethyst, Tibouchina urvilleana
Once you’ve got your major plant features installed, there are always small spaces that need to be filled or accented. Depending on how much maintenance you want to handle you can choose either exotic-looking hardy plants or those on the tender tropical fringe. For hardy perennials I like to use Cape Fuchsia (Phygelius Z7), Euphorbia polychroma ‘Bonfire’ (Z5) or the ground-hugging Ice Plant Delosperma ‘Fire Spinner’ (Z5). California Lilac (Ceanothus ‘Victoria’ Z7) and Sambucus ‘Black Lace’ (Z4) are two larger shrubs that also fit right into this aesthetic. On the more tropical side Fremontodendron ‘California Glory’ (Z8) will gladly fill any sunny vertical space, while the novel Honey Bush (Melianthus major Z9) will intrigue the children (or big kids, like me) with its peanut butter scented foliage. New Zealand Flax or Phormium (Z8) makes a bold focal point for any planter and for partial shade to sheltered sunny patches below your palms, try Kahili Ginger or Hedychium gardnerianum (Z8).
Delosperma Fire Spinner, Euphorbia Bonfire, Fremontodendron California Glory, Hedychium gardnerianum, Melianthus major, Phormium Pink Stripe, Phygelius Cherry Ripe, Sambucus Black Lace
While this ends my blog this week, I have to admit that I have only scratched the surface of potential plant material for a tropical landscape. If I could leave you with one piece of advice it would be to be patient in your search for the more exotic features, as the supply of these is not as plentiful as it was in the peak of this trend which was several decades ago.
All Images Copyright 2020 MK Lascelle