The right tree in the right soil thrives. Match tree to soil and they do their own thing for decades.
Here is the practical soil-to-tree guide for Australian conditions, with five workhorse picks for the main soil types you'll meet.
Test before you plant
Dig a 30cm hole. Squeeze a handful of moist soil. If it crumbles freely, you have sand or sandy loam. If it forms a tight ball and stays sticky, you have clay. Somewhere in between is loam.
Fill the hole with water and time how long it drains. Under four hours is great drainage. Over twelve hours is on the slow side. This determines the easiest tree picks for long-term planting.
Sandy soils
Drains fast, nutrients leach. Pick natives that evolved in sand. Banksia integrifolia thrives where most trees would prefer richer ground. Add Eucalypts and Olives for variety. Magnolias and most ornamental flowering trees love a richer soil profile, so a layer of compost gets them off to a flying start.
Clay soils
Holds water, holds nutrients with workable drainage. Waterhousea is the native pick. Liquidambar and London Plane love clay with workable drainage. Improve with gypsum and compost, mound up if drainage is slow.
Poor or rocky soils
Mediterranean trees and tough natives. Olives are the champion. Banksias, Eucalypts and Brachychitons all manage. Moisture-loving species prefer richer ground, so save them for a more enriched bed.
Adaptable across most soils
Ficus Hillii performs reliably across sandy, loam and improved clay. The default pick when soil is variable, unknown or you want a workhorse evergreen.
Rich loam
The dream soil. Magnolias, Crepe Myrtles, Japanese Maples, Camellias all thrive. Magnolia Coolwyn Gloss rewards rich loam with the heaviest flowering.
Improve what you have
Heavy clay improves with gypsum and compost. Sandy soils improve with compost and well-rotted organic matter. Poor soils take longer but every load of organic matter helps. Most established trees can handle slightly imperfect soil if drainage is workable.
Frequently asked questions
Can I plant trees in pure clay?
Yes, with care. Open up drainage, mound up and pick tolerant species. Waterhousea, Liquidambar and London Plane all love it.
What about hydrophobic sand?
Water-repellent sandy soils respond to a wetting agent and deep organic matter before planting. Banksias and Eucalypts love it most.
How much soil improvement is too much?
Don't backfill a planting hole with pure compost or potting mix. Improve the wider area, not just the hole, so roots head outward into the surrounding soil.
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