Who hasn’t bought a plant, nurtured it for months, only to watch it become too big, spread too wide, struggle in the chosen spot, or simply die?
I certainly have.
When I first started gardening, I was convinced I could grow a productive vegetable patch beneath my crepe myrtle. During winter, everything seemed to be going beautifully. The tree was dormant, my vegetables were growing, and I was feeling rather pleased with myself.
Then spring arrived.
As the crepe myrtle came back to life, its shallow, vigorous roots quickly claimed the surrounding soil. My vegetables didn’t die, but they became visibly unhappy. Growth slowed, leaves lost their vigour, and harvests were disappointing. The vegetables and the tree were competing for the same water and nutrients, and the tree was winning.
It was an important lesson: successful gardens aren’t created by choosing plants we love. They’re created by choosing plants that suit the conditions we have.
So before heading to the nursery, here are four things to consider.
1. How much sunlight does the area receive?
This is the most important factor.
You can improve your soil. You can adjust watering. But there is very little you can do to change how much sunlight a particular part of your garden receives.
Spend a few days observing the space. How many hours of direct sun does it get? Sunlight can vary by season so you must keep track or you can download an sun tracker app.
Identifying your garden’s light conditions
- Full sun: 6 or more hours of direct sunlight
- Part sun or part shade: 3–6 hours
- Full shade: less than 3 hours
A plant that requires full sun is unlikely to thrive in shade, no matter how much care you provide. Likewise, a shade-loving plant may struggle in hot afternoon sun.
Matching plants to available light is one of the easiest ways to improve your chances of success.
2. Understand your soil
Soil is the foundation of every garden.
Different plants prefer different soil conditions. Some enjoy free-draining sandy soils, while others prefer richer soils that retain more moisture.
Before choosing plants, consider:
- Is the soil sandy, clay-based, or somewhere in between?
- Does water drain quickly or remain wet after rain?
- Is the soil rich in organic matter?
The good news is that soil can usually be improved over time with compost, mulch, and organic matter. Understanding your starting point simply helps you choose plants that are more likely to thrive.
3. Consider existing vegetation
Plants don’t grow in isolation.
Trees, shrubs, hedges, and even neighbouring plants can have a significant impact on growing conditions.
Large trees may create shade, compete for water, or develop extensive root systems. Fast-growing shrubs can crowd out smaller plants. Dense vegetation can also affect airflow and moisture levels.
My experience with the crepe myrtle taught me that understanding what is already growing in a space can be just as important as deciding what to add.
4. What do you want the plant to do?
Before selecting a plant, ask yourself a simple question: What job do I want this plant to perform? Your answer will help narrow down the options.
For example:
Add colour and interest: Ornamental plants provide colour, texture and seasonal interest.
Grow food: Edible plants produce fruit, vegetables, herbs and edible flowers.
Create privacy: Screening plants help block unwanted views and define outdoor spaces.
Provide shade: Trees and large shrubs help cool outdoor areas and protect plants from harsh afternoon sun.
Support wildlife: Habitat plants attract birds, bees, butterflies and other beneficial insects.
Suppress weeds: Groundcovers help cover bare soil and reduce weed growth.
Create structure: Feature plants provide form, height and year-round interest in the garden.
Stabilise slopes: Plants with extensive root systems can help reduce erosion on embankments and sloping sites.
Once you’re clear about the purpose (many plants can serve more than one purpose), choosing suitable plants becomes much easier.
Creating your plant list
After considering sunlight, soil, existing vegetation, and purpose, you can begin creating a shortlist of plants that suit your conditions.
Let’s imagine a small east-facing garden in Hornsby Shire that receives around four hours of direct morning sun. The soil is sandy and free-draining, and there are mature trees nearby creating some root competition and afternoon shade.
Depending on the purpose of the garden, suitable plant choices might include:
Edibles: Coriander, kale, lettuce, parsley, rocket, silverbeet, spring onions, strawberries
Australian Natives:Correa alba, Crowea exalata, Dianella caerulea, Goodenia ovata, Indigofera australis, Scaevola aemula, Viola hederacea
Ornamental Plants: Azaleas and rhododendrons, camellias, hellebores, heucheras, hydrangeas, loropetalum, Plectranthus ‘Mona Lavender’
Every garden is unique. Even within Hornsby Shire, factors such as soil depth, tree roots, drainage, aspect and maintenance preferences can significantly influence plant selection. That’s why I always start with a site assessment before making recommendations.
The right plant in the right place
One of the most valuable lessons gardening has taught me is that plant selection isn’t about finding the “best” plant.
It’s about finding the right plant for the right place.
When you understand your garden’s conditions and choose plants accordingly, you’ll spend less time replacing struggling plants and more time enjoying a healthy, thriving garden.