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7 Garden design lessons from the Rock Garden at RBG (Royal Botanical Gardens, Hamilton, ON)


Recently, we visited the famous Rock Garden at the Royal Botanical Gardens (RBG) in Hamilton, Ontario. The Rock Garden re-opened to the public after a four year, $20 million renovation on May 20, 2016 to huge accolades and we wanted to see it for ourselves.


The RBG is the largest botanical garden in Canada and was patterned after the Kew Gardens in Richmond-upon-Thames west of London, England. The Rock Garden was originally built in an abandoned gravel pit in 1930-31, giving the sunken garden a “bowl” shape. In the Depression, the construction of the Rock Garden was actually an important employment opportunity for Hamilton labourers.

The 5.5 acre bowl of the Rock Garden kept 39 original trees and large shrubs and added thousands. The total number of plants is now an astonishing 143,800. So, it’s good to refurbish a garden—at least every 80 years, or so.


Janet Rosenberg and Studio in Toronto was handed the challenge of updating the landscaping at the RBG's rock garden.


The Rock Garden embraces environmentally friendly trends in garden design and management while respecting the integrity of its heritage setting. It incorporates principles of sustainability in its plant selection and layout including pollinator-friendly plants, species native to Ontario, and a palette of drought-tolerant perennials that provides broad sweeps of changing colour and texture through the seasons. Inspired by the work of Dutch landscape designer Piet Oudolf, the garden evokes a natural settings using ornamental species that grow together harmoniously.


From a garden design perspective, the Rock Garden contains great lessons in how to design a garden that has flow, mystery, and delights around every corner. Here are seven garden design lessons from the Rock Garden:


The use of natural stone in the garden. Yes, it is a ROCK garden. Rocks give a garden instant “age” and “permanence.” Rocks and plants are a natural pairing. We have written about this before and we will write about it many more times. Boulders, cut stones, or river rocks—all work great in gardens.

Water features make a garden come alive CREDIT -

Water features. The Rock Garden has several water features including fountains, a waterfall, and a man-made water course running through it. The sound of water in a garden is always pleasant and restful. Equally important, a water source is critical if you want to attract birds to your garden. A simple water feature can be a bird bath, or a half-barrel that acts like a very small pond. There are 277 bird species that visit the Rock Garden.


Changes of levels. Situated in a former quarry, the Rock Garden has many natural level changes. Level changes give the garden visitor many places to focus on, many elements to take in. If you look at a horizon, it is all flat. Put in some verticals to break it up, and you’ve created changes of levels. In a garden, level changes are an invitation to walk around and experience it. The main idea is that the garden visitor has to walk around to see and appreciate the entire garden.

Simple ways you can create level changes in a small backyard garden: add tall planters or construct 12-inch or 24-inch high plant beds using wood or stone; underplant trees and shrubs with shorter perennials and annuals, and install trellises and climbers (such as clematis or ivy) to draw the eye upward.


Garden design and landscaping consulting in Oakville, Milton, Burlington, Mississauga, Etobicoke, and Toronto.

In nature, all lines are curves. There are no straight lines in nature; straight lines are 100% man-made. The Rock Garden is all curved lines and paths. Even the water course that runs through it is full of curves. Curves are much more interesting than straight lines. Curves slow down the eye and make you look at what is actually in the garden. Curves say “stop and look” while straight lines say “keep going.”


Select uncommon trees as focal points. The Rock Garden has a micro climate and has a number of exotic species of trees such as a ‘Cobra’ Norway Spruce, European Larch ‘Varied Directions’, and a Swiss Mountain Pine. If you have a small garden and only have room for one tree—a specimen tree that acts as a focal point in the garden—it is worth the effort to select and hunt down an uncommon tree.


Mass plantings of perennials make huge impact in a garden design. There are mass plantings of hostas, astilbe, bergenia, and Siberian iris. Many garden designers believe that in order to get a good look at a plant, you actually need a mass planting so you can appreciate the leaves and flowers. And it is true!


In garden design, odd numbers work better than even numbers. If you want to do a grouping of trees, shrubs or perennials, odd numbers like 3, 5, 7, 9, and so on look much more natural than even numbers.

VISITOR INFORMATION:  Located at 1210 York Blvd., Hamilton, the Rock Garden at the RBG is open daily from 10 a.m. to 8 p.m. For more information, go to, or call 905-527-1158; toll free 1-800-694-4769.

A mass planting of Siberian iris at the Rock Garden, Royal Botanical Gardens, Hamilton, Ontario
A European larch 'Varied Directions' at the Rock Garden, Royal Botanical Gardens, Hamilton, Ontario.
A panoramic view of the new Rock Garden, Royal Botanical Gardens, Hamilton, Ontario.
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