Lomatia is a genus of evergreen shrubs and small trees in family Proteaceae, native to Chile, Argentina, Australia, and Tasmania. The species most commonly grown in UK gardens is L. ferruginea, the Chilean lomatia, and it is one of the genuinely extraordinary plants available to gardeners in mild parts of the country. The deeply divided, fern-like leaves have a rusty-red underside (the name "ferruginea" means rust-coloured), the new growth emerges bronzed, and the orange-red flowers that appear on mature plants are unlike anything else in a temperate border. When those leaves begin to curl, the plant is usually pointing toward one of two problems that need prompt attention.
Cause 1: Cold wind damage and frost
This is the primary cause of curling leaves on lomatia in the UK, and it is worth understanding clearly because lomatia's reputation can mislead gardeners in both directions. It is hardier than most Proteaceae: while grevillea, hakea, and many proteas are marginal even in the south-west of England, L. ferruginea carries an RHS hardiness rating of H3 to H4 depending on the site, and established specimens grow successfully in Cornwall, Devon, west Wales, sheltered coastal positions, and throughout much of southern Ireland. However, "hardier than most Proteaceae" does not mean it will tolerate a cold exposed position without consequence.
The immediate problem is almost never the temperature alone. It is cold, drying wind combined with frost. The deeply divided, fern-like leaves have a much greater surface area relative to their stem than a simple broad leaf, which means they lose moisture to cold air faster. A hard easterly or northerly wind in January or February will cause the leaves to curl inward, turn brown at the margins, and hang limp even when the air temperature has not dropped to a damaging level. If a hard frost follows, damage to unprepared plants can be severe: frosts below approximately -7°C to -8°C will damage or kill specimens that are not well-established and sheltered.
Young plants are the most vulnerable. A freshly planted L. ferruginea going into its first winter needs shelter from cold winds above all else. A south or west-facing wall provides useful protection in marginal areas, and this wall-trained approach can extend the range of the plant considerably into parts of England where it would otherwise be unreliable. Mulch the root zone generously in autumn to protect against ground frost, using a thick layer of bark or well-rotted leaf mould kept a few centimetres clear of the stem.
If cold damage has already occurred, do not cut back until mid-spring. Lomatia can be slow to show signs of recovery, and stems that appear dead in February may still push new growth from lower down. Scratch the bark below the damaged section: green and slightly moist underneath means the stem is alive. Prune to just above the highest live bud once you are confident, and give the plant the rest of the growing season to rebuild.
Cause 2: Phosphorus toxicity
This cause is critical to flag because many UK gardeners who encounter lomatia do not immediately connect it to grevillea, banksia, hakea, or protea. The plants look very different and come from different continents, but they all belong to Proteaceae, and the family carries an absolute sensitivity to phosphorus that applies equally to every genus within it.
Lomatia evolved in phosphorus-poor South American and Australian soils. Its roots developed specialised cluster-root structures capable of extracting the tiny quantities of phosphorus available in those ancient, depleted substrates. Those same roots have no mechanism for shutting out phosphorus when it is abundant. Apply a standard garden fertiliser, bone meal, blood fish and bone, a balanced slow-release granule, or even enrich the soil with compost that has been fed with a general-purpose fertiliser, and the plant absorbs phosphorus at a rate it cannot process. The result is toxicity that progresses from leaf curling and tip browning through to general decline and death.
The rule for lomatia is the same as for every other Proteaceae: never use any product containing phosphorus. Use only fertilisers specifically labelled for Proteaceae, Australian natives, or South African plants, which are formulated with negligible or zero phosphorus. A dilute seaweed extract in spring provides potassium and trace elements without significant phosphorus and is a safe option. In practice, lomatia planted in a suitable acid soil in a UK woodland garden rarely needs feeding at all, and leaving it alone is often the safest approach.
If you suspect phosphorus toxicity has already occurred, flush the root zone with plain water over several days to leach out what you can, switch immediately to a phosphorus-free product, and accept that recovery will be slow. In a container, repotting into fresh ericaceous compost mixed with extra grit may be more effective than flushing alone.
Other causes to consider
Drought in newly planted specimens. Lomatia is different from most Proteaceae in this respect: it comes from moist Chilean forest rather than the dry Australian bush, and it needs consistently moist conditions. A newly planted specimen that dries out at the root in its first summer will respond with curling and wilting leaves. Water thoroughly and regularly in the first two seasons, and maintain a moisture-retentive mulch. Once established in suitable soil, lomatia copes better, but it will not tolerate the dry summer conditions that grevillea handles without difficulty.
Waterlogging in compacted soils. Moist does not mean waterlogged. Lomatia needs good drainage as well as consistent moisture, and heavy clay soils that sit wet through winter will cause root problems. Incorporate grit when planting on heavier soils, or raise the planting level slightly to improve drainage around the root zone.
Root disturbance. Lomatia resents having its roots disturbed, as do most Proteaceae. If a plant has been moved, divided, or had significant root damage during planting, leaf curl and general stress can follow. Choose the permanent position carefully before planting, and handle the root ball gently to avoid breaking it apart. Once established, leave the plant undisturbed.
Slug damage on young growth. The delicate new leaves that emerge in spring are particularly attractive to slugs. The divided, soft new growth is much more palatable than mature foliage, and slug damage on emerging leaves can cause them to curl and distort as they develop. Check young growth on mild, damp nights in spring and protect with slug controls if damage is occurring.
Lomatia in UK gardens: a plant that deserves wider recognition
L. ferruginea is one of the finest foliage plants available to UK gardeners and is significantly underplanted compared to its merit. The fern-like, deeply divided leaves with their rusty undersides bring a genuinely exotic quality to sheltered woodland gardens, and the plant grows into an impressive large shrub or small tree over time in mild conditions. In Cornwall, Devon, the west coast of Scotland, and throughout mild parts of Ireland, established specimens demonstrate what the plant can do when it is sited correctly. It pairs beautifully with tree ferns, large-leaved rhododendrons, and other architectural plants that share its preference for shelter, acid soil, and dappled light.
The three rules that cover almost every UK failure are: protect from cold drying winds without exception, never use phosphorus-containing fertiliser, and keep the soil consistently moist but freely draining. Get those right and lomatia is a more reliable garden plant than it might appear, and more rewarding than almost anything else you can plant in the same conditions.
Frequently asked questions
Does the phosphorus rule apply to lomatia as well as other Proteaceae?
Yes, exactly the same rule applies. Lomatia is a true member of Proteaceae and shares the family's critical sensitivity to phosphorus. It evolved in nutrient-poor South American and Australian soils where phosphorus is almost entirely absent, and its roots cannot regulate uptake when the element is present in normal garden concentrations. Standard balanced fertilisers, bone meal, blood fish and bone, and most slow-release granules will cause leaf curling, tip dieback, and progressive decline. Use only fertilisers labelled for Proteaceae, Australian natives, or described explicitly as phosphorus-free.
How is lomatia different from other Proteaceae when it comes to watering?
This is the key practical difference. L. ferruginea comes from moist Chilean forest, not the dry Australian bush that grevillea, hakea, and banksia evolved in. It needs consistently moist but well-drained soil and will not tolerate the extended dry periods that those Australian genera handle without difficulty. In the UK this actually works in its favour: our wet climate suits lomatia better than it suits its Australian Proteaceae relatives. Do not let newly planted specimens dry out at the root, and maintain a generous mulch layer to retain moisture during dry spells.
Can lomatia ferruginea survive UK winters?
In mild sheltered gardens, yes. L. ferruginea carries an RHS hardiness rating of H3 to H4 depending on siting, meaning it tolerates short periods to around -5°C to -8°C with shelter. It grows successfully in Cornwall, Devon, west Wales, southern Ireland, and other mild coastal or sheltered positions. A south or west-facing wall provides useful protection in marginal areas. Young plants are significantly more vulnerable than established ones, and hard frosts below -8°C in an unsheltered position will cause serious damage or kill the plant outright. Cold drying winds are often more damaging than the raw temperature.
Why does lomatia resent being moved or disturbed?
Like many Proteaceae, lomatia develops a specific root architecture adapted to its planting site and forms associations with soil microbes that help it extract nutrients from poor soil. Root disturbance breaks these associations and sets the plant back severely. The practical consequence is that you should choose the permanent position carefully before planting and not attempt to transplant an established specimen. If a plant is in the wrong spot, it is generally better to take a cutting and start fresh than to risk moving it.
What other plants grow well alongside lomatia in UK woodland gardens?
Lomatia ferruginea looks extraordinary alongside tree ferns (Dicksonia antarctica is the most reliably hardy), which share its preference for shelter, moist conditions, and dappled light. Large-leaved rhododendrons and other acid-soil shrubs suit the same conditions. Melianthus major provides bold contrasting foliage in similar sheltered settings. For underplanting, shade-tolerant ferns such as Dryopteris or Polystichum echo the divided leaf texture of lomatia without competing for resources. Avoid combining with plants that need full sun and dry soil, as those requirements are incompatible with what lomatia needs to thrive.