Planting a tree sounds simple, and it can be. A well-planted tree takes about 30 minutes of work and rewards you for decades. This guide is written for the home gardener buying their first proper tree, or someone planting a new garden and wanting to set it up for success.
We will cover every step in detail, explain what is happening at each stage, and share the techniques our team uses every day in the nursery. No horticulture degree required.
One quick note before we dig: you do not need to add bagged potting mix, compost, or fertiliser to the planting hole. We explain why in Step 3.
Step 1: Dig wide, not deep
This is the single most important step in planting a tree.
Dig a hole twice as wide as the rootball, but only as deep as the rootball is tall. So if your tree comes in a pot that is 40 cm wide and 40 cm deep, your hole should be roughly 80 cm wide and 40 cm deep.
Why wide? Tree roots grow outwards, not down. They spread horizontally through the top 30 to 60 cm of soil. A wide hole with loosened soil around the edges gives those roots an easy path into the surrounding ground.
Why match the rootball depth? Matching the hole depth to the rootball keeps your tree at the perfect grade for strong, healthy growth and lets the root flare breathe.
If the soil at the bottom of your hole is firm, loosen it lightly with a fork without removing it. You want supportive soil under the rootball so the tree settles at the right height.
Step 2: Plant the tree level with the ground
The root flare is the point where the trunk widens out and joins the roots. It should sit at or just above the surrounding soil level when planting is finished.
To check, lift the tree gently out of its pot or bag and look at the rootball. Sometimes the flare is buried under a centimetre or two of potting mix from the nursery. Brush that off gently so you can see where the real flare starts. That is the line you want at ground level.
Place the tree in the hole and stand back. Check it from a few angles. Is the trunk straight? Is the root flare visible? Adjust before you start backfilling.
Planting level gives the tree the strongest possible start. The root flare can breathe, water moves correctly through the rootball, and the tree settles in quickly.
Step 3: Backfill with the soil you removed
This is the step that surprises most people. Use the same soil you dug out, not rich potting mix or bagged garden soil.
Why? Backfilling with native soil encourages roots to spread out into the surrounding ground, where they anchor the tree firmly for decades and find water and nutrients more efficiently.
Backfill in stages. Add a layer of soil, gently firm it down with your hands or foot, then add another layer. Do not compact it heavily, just enough to remove big air pockets. Keep going until the hole is filled to ground level.
If your soil is very poor (pure sand or rock-hard clay), you can mix in a small amount of compost (no more than 20%) with the backfill. The aim is to match the surrounding soil and let the roots adapt to where they are going to live.
Step 4: Water in deeply
Water slowly and deeply right after planting. Not a quick sprinkle, but a proper soak that reaches the bottom of the rootball.
Use a hose on low pressure and let it run at the base of the tree for several minutes, until the soil is saturated and the water starts pooling. This does two things: it settles the soil into contact with the roots (which is what they need to start drawing moisture) and it removes any remaining air pockets.
If the soil drops noticeably after watering, top it up with more backfill so the surface is level again.
Step 5: Mulch — keep it in a doughnut shape
Spread a layer of mulch 75 mm deep across the planting area, extending out roughly to the dripline of the foliage. Mulch holds moisture, keeps the soil temperature steady, suppresses weeds, and slowly improves the soil as it breaks down.
Keep mulch 5 to 10 cm clear of the trunk in a doughnut shape so the trunk breathes freely and the tree stays healthy.
Good mulch choices for Australian gardens include sugar cane, pea straw, lucerne, aged hardwood chip, or eucalyptus mulch. Sugar cane and pea straw are particularly easy to work with for home gardeners.
Step 6: Stake only if you need to
Most trees do well without staking. A little movement in the wind helps the trunk build strength. If the tree is tall, top-heavy, in an exposed windy site, or has a small rootball relative to its foliage, stake it.
Use two stakes positioned outside the rootball, one either side. Tie the tree with soft flexible ties (old stockings, hessian, or rubber tree ties). The tie should be loose enough that the trunk can sway a little, which builds strength.
Remove stakes after 12 months. A tree that is free to flex develops a strong, self-supporting trunk.
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