Over the past few years our Horticultural team at the Royal Botanic Garden Sydney have trialled and tested over 200 cultivars of plants from across the globe in a new trial garden. The plants were tested for their flower power, vigour and pest resistance so that we can better understand what plants are best suited to the local Sydney climate and specifically within the Garden.
Our Horticultural Director, Jimmy Turner, created the Trial Garden in early 2017 to act as a source of garden information for us and our green-thumb visitors. This data is important as we are always looking to expand and add to displays throughout the Garden. More information about how and why we trial plants can be read here.
Now that the expirements are done and the results are in, we are pleased to share the Top 40 performing annuals, perennials and natives that survived and thrived the trial.
The Trial Garden is located within the Palace Garden precinct near the Conservatorium of Music and at any time, you will see a selection of annuals, perennials, grasses, natives, turf varieties and shrubs being added to see how they perform.
If you are feeling inspired, download your own copy of our Top 40 performing plants so that you can grow them at home and make your neighbours wish they had a garden like yours. All cultivars should be available from better retail garden centres.
Here are Jimmy’s top 5 favourites with his personal tips on how to grow them. Happy planting.
Lobularia Snow Princess
- From a distance this plant looks like drifts of snow in the landscape and the scent is phenomenal. Has been in full bloom for almost three years straight in the trial garden.
- This very easy to grow plant prefers full sun, but will tolerate a bit of late afternoon shade.
- Plants can be spaced at 45 cm and will fill in quickly.
- Water when wilted and apply fertiliser quarterly.
- Snow Princess is happy to reign royally in your garden at any time, so don’t worry about what time of year to plant her.
- Makes a wonderful carpet under roses are other shrubs with bare stems.
Buddleia ‘Wisteria Lane’
- A waterfall of weeping wisteria-like super-scented flowers will bring the bees and butterflies to your yard like a magnet, and probably a few envious neighbours.
- ‘Wisteria Lane’ is a woody shrub for full sun and prefers monthly feeding with fertiliser.
- I recommend pruning the plants each spring to 30 cm to keep the plants full and compact.
- Plants naturally stay under 1.5 m tall.
- There is no bad time of year to plant this lovely shrub.
Isotoma “Fizz and Pop” series
- This Australian native cultivar has giant nectar-rich blossoms in many different colours and withstands temperatures from 4 to 40 C.
- The feathery foliage creates 30 cm mounds dotted with 4 cm blossoms from mid-summer until the end of autumn.
- Works equally well in containers or in ground.
- Plants prefer full sun and once established require little supplemental watering.
- Best planted in early spring.
Salvia hybrid ‘Mystic Spires Blue’
- You can never have enough blue in your garden and this Salvia doesn’t disappoint.
- Easy to grow and always in bloom.
- Prefers full-sun to semi-shade and well-drained soil.
- Perennial in all but the coldest of gardens.
- The 30 cm flower spikes are constantly adorned with butterflies and bees.
- Once established just needs water when wilted.
- Plants will reach 40-70 cm tall by 30-60 cm wide when full grown.
- Best established when planted early spring.
- Hardy perennial in most areas.
Pelargonium ‘Calliope’ series also called ‘Big Red’ or ‘Big Pink’
View the Top 40 here.
- This is a geranium on steroids, and hasn’t stopped blooming in our trials for almost two years.
- You have your choice of 2 colours, glowing fuchsia pink or blazing scarlet red.
- A hybrid between the upright Zonal Geranium and trailing Ivy Geranium.
- The plants are sterile so none of that tedious dead heading!
- Grows equally well in container or in the ground.
- Seldom out of flower.
- Disease and pest resistant plants prefer full sun.
- Once established requiring little water or care.
- Wil eventually reach 45 cm tall and 55 cm across.
Trials to go west
Due to the success of the Trial Garden at the Sydney Garden this will now become an annual process for us.
We are looking to expand to the Australian Botanic Garden Mount Annan which will be dedicated to testing only native plant species and their suitability for home gardens.
Learn more about the trials at the Garden’s new talk In Trials We Trust which you can find more about here.
Tag your success
If you use any of the Top 40 plants share your garden successes with us on social media by tagging us with @rbgsydney #rbgsydney and #rbgtrialgarden.