Oxalis Vulcan Red Plants - Outdoor GROW TROPICALS
Firefern (Molten Lava Sorrel)

Oxalis Vulcan Red

£9.99
Overwinter under coverSun-loving
Pot size
10cm / 0.5L £9.99

FREE tracked delivery on orders over £60

Complete the set up
Simply Houseplant - Tropical Houseplant Potting Mix
The perfect soil Simply Houseplant - Tropical Houseplant Potting Mix · 2.5L · £3.99
Description

Turn up the heat with the Oxalis Vulcan Red, a firefern or molten-lava sorrel (Oxalis vulcanicola) grown for its smouldering leaf colour. The small, clover-shaped leaves are a deep red that darkens to rich burgundy in strong light, mounding into a low cushion of colour, while cheerful little yellow flowers dance above and contrast beautifully with the dark foliage. Drama and glow in one easy pot.

A frost-tender firefern (around RHS H1c to H2), it earns its keep outdoors through the warmer months and comes inside for winter, so its fiery colour returns summer after summer.

That tenderness is really versatility: Vulcan Red is equally at home as a striking houseplant or a summer garden showpiece. It loves bright light, so give it the high light of a conservatory, greenhouse or sunny windowsill indoors, or a bright, sheltered spot outdoors once nights stay reliably above about 10C.

Care is simple and rewarding: keep the compost evenly moist and feed every couple of weeks through summer for the richest colour, trimming lightly now and then to keep the mound full and bushy. It looks superb at the front of exotic borders, spilling from baskets, and even in coastal and exposed gardens given shelter from frost. Pair it with the rosy Oxalis Vulcan Pink or explore more of our hardy exotics, and see what to expect from these vivid summer performers.

Every plant is nursery-grown and hand-selected for strong colour and healthy roots, then packed with care to arrive in top condition.

Live Arrival Guarantee

All plants are covered by our 7-day live arrival guarantee. We pack every order in protective, sustainable packaging designed to keep your plants safe in transit, and every plant is checked before it ships. On the rare occasion something is not right on arrival, we will make it good, provided the plant is still in its original nursery pot.

Find out more

What to Expect

Seasonal by nature: what to expect

  • Grown outdoors, the way nature intended. Weather-tested and hardened in real UK conditions, so they thrive in your garden. A few marks on the older leaves are normal, the sign of a tough, real plant rather than a flaw.
  • It follows the seasons. Depending on when you order, your plant may arrive cut back, dormant or leafless. That's healthy: dormancy is the ideal time to plant.
  • Posted, not posed. Big leafy plants like bananas and gingers may be trimmed or gently folded to travel safely. It does the plant no harm, and it powers away again in spring.

Not sure what to expect from yours? Dormant, cut-back or weather-marked plants are all perfectly healthy and normal. Read what to expect through the seasons

Delivery & returns

Order by 1pm Monday to Friday for same day dispatch. Every plant travels in protective, plant-safe packaging with tracked delivery.

Changed your mind? See our Return Policy.

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How to care for Firefern (Molten Lava Sorrel)

Plant me in full sun and bring me under cover before the frosts.

In their words

What our customers say

Arrived just like the photos - maybe even fuller. Healthy, well-acclimated, and straight into my collection with no issues.

Emily P.

Flawless leaves, stunning variegation, and clearly cared for by experts. It’s already a talking point in my home office.

James R.

Hard to find rare plants that are pet-safe. Ours arrived in perfect condition and looks amazing without any worry.

Sophie L.
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About Firefern (Molten Lava Sorrel)

Oxalis Vulcan Red needs full sun or partial shade and moist but well-drained soil. It is frost tender and must come under cover for winter.

Good for

Coastal & Exposed Exotic Borders Pots & Containers

Hardiness

TenderVery hardy

RHS H1c-H2 · Tender · frost-free only

tender (around RHS H1c to H2); overwinter frost-free at a minimum of around 10C, or take easy cuttings to carry it over.

Position

Full sunPartial shadeSouth-facingEast-facingWest-facingExposedSheltered

full sun for the deepest, darkest red, and it tolerates a little light shade too.

Soil

ChalkClayLoamSandMoist but well-drainedAcid pHAlkaline pHNeutral pH

any fertile, moist but well-drained compost; brilliant in pots and containers and hanging baskets.

Watering

Keep the compost evenly moist through the growing season and feed every couple of weeks with a balanced liquid feed for the best colour. Ease off watering in winter while growth slows. Trim lightly through summer to keep the mound bushy and full. Read moreShow less

Keep the compost evenly moist through the growing season and feed every couple of weeks with a balanced liquid feed for the best colour. Ease off watering in winter while growth slows. Trim lightly through summer to keep the mound bushy and full.

Mature size

Height15-25 cm
Spread20-30 cm

Reaches full size in 1-2 years

Growth habit

Bushy

Flowering

Jun-Sep

Seasonal colour

Foliage

Evergreen (stays evergreen only when kept frost-free over winter)

Pruning

Trim to shape and tidy through summer to keep it bushy; it is not frost hardy, so overwinter it under cover or take cuttings.

Toxicity

Oxalis contains oxalic acid and soluble oxalate salts, so it can cause stomach upset if eaten in quantity and is best kept away from pets and young children. Handling is fine, with no contact toxicity.

Native range

Central America

Family

Oxalidaceae

Also known as

Oxalis Vulcan Red

Genus

Oxalis →
Good to know

Frequently Asked Questions

Is Oxalis Vulcan Red hardy in the UK?

No. It is a tender foliage perennial (around RHS H1c to H2) grown for its deep red foliage, not a hardy plant. Treat it as a summer patio plant: stand it outside once nights stay above about 10C and bring it under cover before the first frosts. See our note on what to expect.

Can I grow it outdoors?

Yes, through the warmer months. It is a classic summer bedding, container and hanging-basket foliage plant. Grow it in pots and containers on a sunny patio, then overwinter it frost-free.

Where should I position it for the best colour?

Full sun brings out the deepest red to burgundy tones, though it tolerates a little light shade. A warm, sheltered spot suits it well, including coastal and exposed gardens once the frosts have passed.

How do I overwinter Oxalis Vulcan Red?

Bring it indoors before the frosts and keep it frost-free at a minimum of around 10C on a bright windowsill or in a heated greenhouse. Water sparingly over winter. Taking a few cuttings in late summer is a good insurance policy.

Is it suitable for pots and hanging baskets?

Ideally so. Its low, mounding and gently trailing habit spills over the edge of a container, making it excellent in pots and baskets and at the front of exotic borders.

Does it flower?

Yes, it carries small yellow flowers through summer that contrast beautifully with the leaves, but it is grown mainly for its deep red foliage rather than the blooms.

Does my plant come with a pot?
Your plant will arrive in its nursery grow pot — the plastic pot it's been growing in. We don't include a decorative pot as standard, and there's a good reason for that: it means you get to choose one that fits your space and style, rather than being stuck with something that doesn't suit your home.

It also means you're not paying extra for a pot you might not want. The nursery pot is perfectly fine to keep your plant in for a while, just pop it inside a decorative cover pot or cache pot and you're good to go. When you're ready to repot (usually after a growing season or when roots start poking out the bottom), you can move it into something more permanent with fresh soil.

If you're not sure what size cover pot to go for, check the pot selector tool listed above, you'll want a decorative pot that's a centimetre or two wider than that to give it a comfortable fit.
How big will my plant be when it arrives?
Every plant on our site includes the pot size (e.g. 12cm) and, where possible, an approximate height. That's the most reliable way to set your expectations, photos can sometimes make a plant look larger or smaller than it really is.

If you're thinking "that sounds quite small for the price," here's something worth knowing: younger, smaller plants almost always adapt better to your home than larger ones. They adjust faster to your light and humidity, put out new growth more quickly, and tend to establish stronger root systems long-term. A plant that grows into your space will usually outperform one that was already big when it arrived.

That said, every plant is an individual. The one you receive may vary slightly in height, shape, or fullness compared to the photo, that's the nature of living things, not a quality issue. We select healthy, well-established specimens, and if you ever feel your plant doesn't match what you were expecting, just get in touch and we'll take a look.
What makes your plants different from the supermarket or garden centre?
There's a big difference between a plant that's been sitting under on a retail shelf and one that's been looked after and cared for by people who specialise in exactly this.

Our plants are grown in house or sourced from specialist nurseries, many of them varieties you simply won't find at your local garden centre or supermarket. Before anything leaves us, it's checked over by our horticultural team to make sure it's healthy, well-rooted, and ready to thrive in your home. We're not shifting volume off a pallet, we're choosing plants we'd want to keep ourselves.

When you buy from a supermarket, you get a plant and a generic care label. When you buy from us, you get the knowledge that comes with it, detailed care guidance, a team you can actually contact if something isn't going right, and the confidence that what's arriving has been looked after properly from the moment it was grown to the moment it reaches your door.

We're a specialist nursery first, not a retailer that happens to sell plants. That's the difference, and you'll see it the moment you open the box.
What should I do when my plant arrives?
First things first, unbox it as soon as you can. Plants don't love being in dark boxes any more than you would, and the sooner yours is out and breathing, the better.

Remove all the packaging carefully, give the soil a check with your finger, and water lightly if it feels dry. Then find it a spot with appropriate light, but avoid putting it straight into harsh direct sun or next to a radiator. Think of it like arriving somewhere new after a long journey: it needs a moment to adjust.

It's completely normal for your plant to look a little tired or droopy after transit. This is called transit stress, and most plants bounce back within a week or two. You might see a yellow leaf or some drooping, don't panic, and resist the urge to overwater or start repotting straight away.

Our advice for the first couple of weeks: leave it in its nursery pot, water it only when the top layer of soil feels dry, and let it acclimatise to your home's light, temperature, and humidity. Once it's settled in and showing signs of new growth, you can think about repotting or moving it to its permanent spot.

Every plant we sell comes with a care guide on the product page so you'll know exactly what it needs going forward. And if anything doesn't look right, get in touch with our team, we're always happy to help.
Will my plant survive being shipped?
Yes! and we go to serious lengths to make sure of it. Every plant is hand-packed by our team with protective wrapping and secure, custom-designed boxes to keep it stable and safe in transit. We've shipped hundreds of thousands of plants across the UK and our packaging methods have been refined over years to handle the bumps and jolts of delivery.

During colder months, we monitor weather forecasts and offer heat packs where needed to protect against frost. In extreme conditions, we may hold your order for a day or two rather than risk sending it out, we'd rather you wait an extra day than receive a stressed plant.

That said, plants are living things, and the occasional transit wobble can happen. If your plant arrives damaged or isn't in the condition you'd expect, just get in touch within 48 hours with a photo, and we'll make it right, whether that's a replacement or a full refund. No fuss.

The short version: we treat every box like it's going to someone who really cares about what's inside, because it is.
Meet the family

Everything about Oxalis

Oxalis, commonly known as Wood Sorrel or the Shamrock Plant, is a diverse genus of plants with over 800 species found worldwide. Many popular houseplant varieties, such as Oxalis triangularis and Oxalis deppei, originate from South America, Africa, and part...

More about Oxalis care
Oxalis Care Guide
Why Grow Tropicals

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Packaged with Care

Packaged with Care

Every order is hand-packed in eco-friendly, protective packaging - refined through thousands of deliveries to ensure your plant arrives healthy, hydrated, and looking its best.

Backed by our Live Arrival Guarantee.

Perfect for Gifting

Perfect for Gifting

From rare collector’s pieces to easy-care favourites, our plants arrive fully potted and ready to enjoy. Add a personalised note at checkout for a thoughtful finishing touch.

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Sustainability at Heart

Sustainability at Heart

All plants are ethically sourced from trusted growers, never wild-collected. Every order ships carbon-neutral in minimal-waste packaging.

Good for your home - and the planet.

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£9.99