Poolside planting: leaf litter, roots and salt

The pool is in, the paving is down, and the strip between the coping and the fence is still bare. It is hot, dry, awkward ground, and whatever goes in will spend the next twenty years either ignored or fished out of the skimmer. Poolside planting is a siting problem before it is a plant problem.

Three constraints decide whether a poolside bed works: where the shed litter lands and how fine it is, what the roots do to paving, coping and pool plumbing, and whether the foliage takes splash and reflected heat. Get the geometry right and a long list of ordinary plants will do.

Roots lift paving long before they reach the shell

The dramatic version, a root cracking a pool shell, is rarely what happens first. What happens first is a woody root thickening under the coping and lifting a paver ten or fifteen millimetres. The bedding sand shifts, the falls change, and water that used to run away from the coping runs towards it. Roots also track along skimmer lines, backwash lines and the hydrostatic valve, because that is where the moisture is.

The control that works is distance. A root barrier along the paving edge is worth installing while the ground is open, but it deflects rather than stops. Anything that builds a thickening woody trunk needs a setback scaled to what it will become, not to the pot in front of you. A raised bed with a masonry wall between soil and paving is the other answer, and it fixes drainage too.

What can sit close to coping is anything whose roots stay fibrous and never turn into timber. Palms qualify, because a palm root spreads rather than swells. So do strappy clumpers: lomandra, dianella, phormium, liriope, mondo grass and dietes all build a fibrous plate that holds soil without pushing anything sideways.

Fine litter costs more than big leaves

Every plant sheds, so the useful question is particle size. Large leaves float, drift to the skimmer and come out with a net in one pass. Fine material behaves differently. Needles, small leaves, tiny florets, stamens, spent petals and seed fluff pass through the skimmer and pump baskets, reach the filter medium and stay there, which means shorter runs between backwashes or cartridge cleans, rising pressure and less flow. Berries and hard capsules sink instead, and need vacuuming off the floor.

A broad-leaved plant near the water can therefore be less work than a fine-leaved one two metres back. Wind decides more than distance in most gardens: work out the prevailing summer breeze, then keep the fine shedders downwind so debris blows away from the water. If that breeze runs from the north east and the skimmer sits on the eastern wall, anything planted north east of the pool is planted in the filter.

Evergreen or deciduous

Deciduous makes thermal sense on the northern and western sides: shade over the paving in summer, sun onto the water in winter. The cost is one concentrated drop in autumn and a fortnight of netting. Evergreen spreads its shedding thinly through the year, but it also keeps the water cold in spring. Neither is clean, so choose on how you want the work distributed; the trade-offs in evergreen or deciduous apply here with the filter added.

Splash, salt and reflected heat

Chlorinated splash is dilute and intermittent, and hard foliage generally shrugs it off. Salt is the part that accumulates. A salt chlorinated pool is far less salty than the sea, but every splash that lands on a bed leaves its salt behind as the water evaporates, every day of summer. Rain flushes an open bed. Under an eave, behind glass fencing, or in a bed that never catches direct rain, salt concentrates in the top layer of soil and shows as burnt leaf tips.

The answer is drainage and flushing rather than species selection: free-draining soil, drip irrigation in the bed rather than reliance on rain a roof line or a fence may intercept, and an occasional deep soak to push salt below the root zone. Plants from exposed coastline handle the rest, which is why coastal planting: salt and wind transfers straight to a poolside strip.

Reflected heat is the other half. Pale paving and the water surface bounce light up into the foliage, and soil beside and under paving stays drier than the rest of the garden. Grey and silver foliage, thick-leaved succulents and hard-leaved natives handle it. Soft thin-leaved shade plants do not.

What to plant in the first two metres

Strappy evergreen clumpers do most of the work. Lomandra Lime Tuff is a compact green tuft that takes reflected heat, splash and neglect, and it runs from 75mm to 250mm, so a long line can go in small and close up. Blue Flax Lily gives a finer blue-green blade and blue flowers, then small berries that drop on paving; treat those as not for eating around children. The low maintenance range carries the same habit in other forms.

Wild Iris is the dependable filler for a hot bed, with the caveat that each white flower lasts a day and then drops, so it adds steady fine litter; keep it back from the coping. Phormium Bronze Warrior brings a bigger bronze strap for structure, takes salt well, and asks only that you pull the old leaves out once a year. Between pavers and stepping stones, Dwarf Mondo Grass sheds very little and takes occasional footfall, though not a daily route.

For heat and form, Foxtail Agave is the agave without terminal spines, which matters where people walk past barefoot; the sap can irritate skin and eyes, so wear gloves when you tidy it. The rest of the succulent range suits hot dry pockets between paving and fence, if the bed drains. Cordyline adds colour in the same conditions, though the Ti Plant forms are toxic to cats and dogs. Westringia clips into a low grey hedge and takes salt and wind, but sheds small leaves and flowers, so keep it downwind of the skimmer.

Palms, and where the fronds land

Palms suit poolside because the roots behave, they are evergreen, and the litter is large. The question is the drop zone. Kentia Palm is slow, takes shade or part sun, and sheds a whole frond now and then rather than a constant trickle. Lady Palm is a clumping palm for a shaded corner or a large pot. Both work close to paving.

Taller palms in the palm range want a setback, not for their roots but for what comes down. Foxtail, Bangalow and Alexandra shed heavy fronds cleanly, and a frond landing on glass fencing or in the water is a different problem from a leaf. Bangalow and Alexandra also carry large flower spikes and masses of small fruit, fine litter that stains paving, so site them as a backdrop. Golden Cane screens well but sheds panicles and fruit, so hold it back from the coping.

What not to do

Keep figs and ficus of any kind out of a pool yard: the roots are aggressive, they travel, and they find plumbing. Liquidambar combines surface roots with spiked seed capsules that sink. Silver birch and elms root at the surface and shed small leaves. Cocos Palm drops heavy fruit and frond and seeds itself through every bed. Gums over the water bring bark ribbons, gumnuts and limb drop. Lilly pilly works as a set-back screen but not at the coping, where the fruit stains paving and sinks.

Bottlebrush and grevillea upwind cause the same trouble: spent flowers are fine litter, and both bring birds and bees to the water's edge. Agapanthus at the coping is that story at scale, since one head is hundreds of florets, it seeds itself, and it is an environmental weed in some districts. Do not plant euphorbia where people walk barefoot, because the milky sap is a serious irritant to skin and eyes.

Two non-plant rules matter as much. Do not discharge backwash into a poolside bed; it is saline, chlorinated and repeated, and your council has rules about where it goes. And check the non-climbable zone outside your pool barrier before you plant or place a pot, because a shrub, branch or planter in that zone can make a compliant fence non-compliant.

Order of operations

Set the beds out before you buy. Mark the setbacks for anything woody, decide where the fine shedders can go, and put in edging, barriers and drainage while the ground is open. Then buy to the plan: strappy plants can go in at 140mm or 200mm because they close up quickly, while palms are slow, so buy those at the size you want. Every order ships farm-direct with flat $99 delivery in QLD, NSW, VIC, SA, ACT and WA, a $399 minimum order, and the 30-Day Healthy Plant Guarantee.