Crocosmia ‘John Boots’ (Montbretia): Complete Growing Guide

A Compact Montbretia with Starry Yellow Charm

If you’ve grown Crocosmia ‘Lucifer’ and found it slightly overwhelming — those towering scarlet stems muscling out everything in the border — then ‘John Boots’ might be exactly what you need. It’s a gentler, more compact montbretia with canary-yellow, starry, flat-faced flowers that bloom on graceful arching stems from midsummer into early autumn. Where ‘Lucifer’ shouts, ‘John Boots’ hums quietly — but it’s no less effective.

Introduced around 2000 by Dutch nurseryman Willem Heemskerk, ‘John Boots’ is a Crocosmia × crocosmiiflora hybrid — the same cross between C. aurea and C. pottsii that French breeder Victor Lemoine first created in 1880. The cultivar name likely honours Paul Boots, a figure in Dutch horticulture. What sets it apart from other yellow-toned montbretias like ‘George Davison’ is its flower form: the petals are wider-spaced and more starry, giving each bloom a lighter, more open appearance rather than the typical funnel shape. The flowers also have paler centres with golden undersides, and the burnt-orange seed heads that follow extend ornamental interest well into autumn.

At just 50–100 cm (20–40 inches) tall, ‘John Boots’ fits comfortably in the middle of a border, in containers, or threaded through a cottage garden without dominating. It’s hardy to RHS H4 (roughly USDA zones 6–9), deer resistant, and attractive to bees and butterflies — an easy, reliable plant that earns its space without demanding constant attention.

Quick Reference

Care Guide

Light

Full sun — at least six hours of direct light daily — produces the strongest flowering and the sturdiest stems. ‘John Boots’ tolerates partial shade (four to six hours), but expect fewer flowers and slightly leggier growth. An east-, south-, or west-facing position suits it well.

In zones 8–9, a touch of afternoon shade actually benefits the flowers by preventing bleaching. In cooler zones (6–7), give it the sunniest spot you have — the extra warmth encourages earlier emergence in spring and better corm ripening in autumn, both of which improve winter survival and next year’s display.

Planting Corms

Plant corms in spring after the last hard frost — typically March to April in most zones. Spring planting gives the corms a full growing season to establish roots before their first winter, which significantly improves survival rates in zones 6–7.

Depth: Plant corms 8–10 cm (3–4 inches) deep, measured from the top of the corm to the soil surface. The RHS recommends this depth for adequate frost protection while allowing shoots to emerge without too much resistance [1].

Spacing: Set corms 10–20 cm (4–8 inches) apart. Closer spacing creates a denser display from year one; wider spacing gives clumps room to naturalise over several years without needing division as quickly.

Orientation: Point the slightly pointed end upward. If you can’t tell top from bottom — and with Crocosmia corms this is genuinely tricky — plant them on their side. The shoot will find its way up.

I’ve found that planting in groups of at least seven corms gives the best visual impact — a single corm looks sparse, but a cluster of seven or more creates the drift effect that makes montbretia so effective in borders.

Soil

Crocosmia thrives in fertile, humus-rich, moist but well-drained soil. ‘John Boots’ is more soil-tolerant than many bulbous plants — the RHS notes it handles clay, loam, sand, and even chalk [1]. The critical requirement is that winter waterlogging must be avoided, as sitting in cold, wet soil is what kills corms.

For heavy clay, work in coarse grit or perlite before planting to improve drainage. In very sandy soil, add plenty of garden compost or well-rotted manure to improve moisture retention during the growing season. A neutral to slightly acidic pH (6.0–7.0) is ideal, though ‘John Boots’ adapts happily up to pH 8.0.

Watering

Keep the soil evenly moist during the active growing season — spring through flowering — particularly during bud formation. Water stress at this stage reduces both flower quantity and quality. One or two deep soakings per week during dry spells is more effective than frequent light watering.

Once established (after two to three growing seasons), ‘John Boots’ develops reasonable drought tolerance thanks to its corm-based water storage. However, it flowers noticeably better with consistent moisture — the University of Florida IFAS notes that Crocosmia is drought-tolerant once established but performs best with regular watering [2].

After flowering, as the foliage yellows and dies back, reduce watering. The corms are dormant in winter and need relatively dry conditions — overwatering during dormancy is the fastest route to corm rot.

Temperature and Climate

Hardy in USDA zones 6–9, ‘John Boots’ handles temperatures down to approximately −10°C (14°F). In zones 6–7, a thick winter mulch (8–10 cm / 3–4 inches of straw, bark chips, or garden compost) applied in late autumn provides crucial insulation. Remove it gradually in early spring as temperatures rise to prevent the shoots rotting under damp mulch.

In zones 8–9, no winter protection is needed — corms overwinter happily in the ground. In the coldest parts of zone 6 or exposed gardens, consider lifting corms in late autumn as insurance: dig them after the foliage has fully died back, dry for two to three days in a cool, airy spot, and store in paper bags or trays of barely damp sand at 5–10°C (40–50°F). Replant in spring.

Feeding

Ground-planted Crocosmia in reasonably fertile soil rarely needs supplemental feeding. The RHS notes that ground-grown plants generally don’t require feeding at all [1]. If your soil is poor or very sandy, a light application of balanced slow-release fertiliser in early spring as shoots emerge is sufficient. Avoid high-nitrogen feeds, which promote lush foliage at the expense of flowers.

Container-grown plants are different — they benefit from fortnightly feeds with a high-potassium liquid fertiliser (tomato feed is ideal) from when the flower buds form until the end of flowering [1].

Post-Bloom Care

After flowering, leave the foliage intact until it yellows and dies back naturally — the leaves are photosynthesising and feeding the corms for next year’s display. Don’t cut, braid, or tie the foliage; just let it go. Once fully yellowed (usually by late autumn), remove dead leaves to tidy up.

The burnt-orange seed heads of ‘John Boots’ are genuinely ornamental — leave them on the stems for architectural interest through autumn if you don’t mind the slightly wild look. They also dry well for indoor arrangements. Prune dead stems before spring growth begins.

Propagation

Division (Recommended)

Division is the best method for named cultivars — it’s reliable, maintains the exact characteristics of ‘John Boots’, and keeps clumps vigorous. Divide every three to five years in early spring, just as new growth appears.

Dig up the entire clump and you’ll see chains of corms stacked on top of each other — each year’s new corm forms on top of the previous year’s. Carefully separate individual corms or small groups, each with at least one visible growing point (an “eye” or emerging shoot). Replant immediately at the same depth and spacing, and water thoroughly. Most divisions flower in their second year after splitting [1].

Division also solves the most common Crocosmia problem: overcrowding. Left undivided for too long, clumps become congested, flowering declines, and the centre of the clump goes unproductive. NC State Extension recommends dividing every three to four years to maintain vigour [3].

Cormlets and Offsets

Each year, the mother corm produces one or more daughter corms (cormlets) alongside or on top of itself. This natural multiplication creates the expanding clumps over time. When dividing, you’ll notice these chains — the youngest, most vigorous corms are at the top; the oldest, most depleted ones are at the bottom. Prioritise replanting the top corms with visible growing points, as these establish fastest and flower soonest. Old, shrivelled corms at the base of the chain can be discarded.

Some Crocosmia cultivars also produce underground stolons — horizontal runners that sprout new growth at their tips. If you spot these when dividing, detach them with their fibrous roots and plant them separately. They’ll develop into independent plants within a season or two.

Seed (Not Recommended for Cultivars)

Seed propagation is possible but impractical for ‘John Boots’. Seedlings won’t come true to the parent — you’ll get variable offspring with unpredictable flower colour and form. Seeds also take three to five years to reach flowering size. Stick with division unless you’re deliberately trying to create new hybrid variations.

Common Problems and Solutions

Overcrowding and Declining Flowers

The most frequent complaint with any established Crocosmia. After three to five years, corms multiply so densely that they compete for nutrients and water, and flowering drops off sharply. The fix is simple: lift, divide, and replant with proper spacing in early spring. You’ll be amazed at the difference — a congested, barely flowering clump can return to full bloom in a single season after division.

Corm Rot

Caused by waterlogged soil, particularly in winter when corms are dormant. Symptoms: corms fail to emerge in spring, or emerge weakly and collapse. There’s no cure for rotting corms — prevention is the only approach. Ensure good drainage before planting, avoid low-lying areas that collect standing water, and never overwater during dormancy. In heavy clay, raise the planting area slightly or add generous amounts of grit at planting time. Discard any soft or mushy corms — don’t compost them, as the rot can survive in compost.

Red Spider Mite

The RHS specifically lists glasshouse red spider mite as the main pest for ‘John Boots’ [1]. These tiny mites thrive in hot, dry conditions and cause stippled, yellowing foliage. Outdoors, they’re rarely a serious problem — natural rainfall and humidity keep populations in check. In hot, dry summers or under glass, increase humidity by hosing foliage with a strong water spray. Severe infestations respond to insecticidal soap or horticultural oil.

Thrips

Gladiolus thrips (a related Iridaceae pest) can cause silvering and distortion of leaves and brown patches on flowers. Thrips are controllable with insecticidal soap or neem oil applied at the first sign of damage. Severe infestations can also leave grey-brown patches on stored corms — inspect corms before planting and discard any with visible thrips damage.

Flopping Stems

Less common with ‘John Boots’ than with taller cultivars like ‘Lucifer’, but it can happen in very exposed positions or overly rich soil. The solution: plant in full sun (shade causes lankier growth), avoid high-nitrogen fertilisers, and if necessary, use discreet plant supports or position ‘John Boots’ behind lower-growing plants that provide natural support.

Failure to Flower

Beyond overcrowding, the other common causes are: corms planted too shallow (less than 8 cm deep), insufficient sunlight (less than six hours daily), or foliage cut back too early the previous year. New corms often skip flowering in their first year while they establish — this is completely normal. Give them a second season before worrying.

Invasiveness: An Important Note

Crocosmia × crocosmiiflora — the hybrid group that includes ‘John Boots’ — has naturalised widely beyond its South African origins and is classified as invasive in several regions. In the UK, it’s listed on Schedule 9 of the Wildlife and Countryside Act 1981, making it an offence to plant it, or cause it to grow, in the wild in England and Wales [1]. In the United States, it has naturalised along the Pacific Northwest coast, though it’s not federally listed as noxious.

In garden settings, ‘John Boots’ is well-behaved — its compact habit and moderate growth rate make it less aggressive than the species hybrid. But sensible precautions apply: never dump unwanted corms in green waste bins, compost heaps, or wild areas. Corms can survive in finished compost and spread from there. Dispose of removed corms responsibly — bag them in household waste or dry them thoroughly and burn them. Regular division every three to five years keeps garden clumps from overextending their welcome.

Garden Design and Companion Plants

Design Uses

The arching flower sprays and compact stature of ‘John Boots’ make it a versatile border plant. Its canary-yellow flowers bridge the gap between the cooler blues and purples of early summer and the hot reds and oranges of late summer, making it a natural transition plant in any mixed border.

Plant in drifts of seven to fifteen corms for the best visual effect. The sword-shaped foliage provides structural interest from spring, even before the flowers open in July. In cottage gardens, it adds relaxed charm; in more contemporary plantings, the clean lines of the foliage and the repeated rhythm of the flower sprays create a sense of order.

The cut flower value is excellent. Stems last one to two weeks in a vase, and the arching form adds movement and elegance to arrangements. The burnt-orange seed heads also dry beautifully for long-lasting displays — I’ve had them hold their shape for months in a dry vase without any special treatment.

Companion Plants

• Agapanthus (especially blue varieties) — the classic blue-and-yellow contrast. Both flower in the same period and enjoy the same sunny, well-drained conditions. The upright agapanthus globes and arching Crocosmia sprays create a striking textural partnership.
• Echinacea ‘Sundown’ — sunset-orange coneflowers add a warmer counterpoint to the canary yellow. Both are midsummer bloomers with similar moisture requirements.
• Kniphofia ‘Flamenco Mix’ — similar structure (vertical spikes from grassy foliage) in complementary warm tones. Together they create a fiery late-summer display.
• Miscanthus sinensis ‘Gracillimus’ — fine-textured grass provides a soft foil for the bolder Crocosmia foliage and adds movement and autumn interest after the Crocosmia has finished.
• Rudbeckia hirta ‘Prairie Sun’ — golden-yellow daisies echo the yellow tones and bloom simultaneously. The upright daisies and arching Crocosmia sprays make a dynamic textural combination.
• Salvia nemorosa — deep purple-blue flower spikes create a strong complementary colour contrast against the yellow Crocosmia. Both thrive in full sun and well-drained soil.

Container Growing

‘John Boots’ performs well in containers thanks to its compact size. Use a pot at least 30 cm (12 inches) in diameter with good drainage holes. Plant corms 8 cm deep and 10 cm apart in multi-purpose compost mixed with about 20% perlite or grit for drainage. Feed fortnightly with a high-potassium liquid fertiliser (tomato feed) from bud formation through flowering.

In zones 6–7, bring containers under cover (unheated greenhouse, shed, or against a sheltered house wall) for winter. In zones 8–9, containers can stay outdoors year-round. The arching flower sprays look particularly dramatic spilling over the edge of a tall pot on a sunny patio.

Frequently Asked Questions

When should I plant Crocosmia ‘John Boots’ corms?

Plant in spring after the last hard frost — typically March to April. Spring planting gives corms a full growing season to establish before winter. In warmer zones (8–9), autumn planting is also possible, but spring is safer in zones 6–7 where winter frost could damage newly planted corms that haven’t yet rooted.

Why isn’t my Crocosmia ‘John Boots’ flowering?

The three most common causes are: it’s a newly planted corm (most won’t flower until their second year), the clump is overcrowded (divide in early spring), or it’s not getting enough sun (needs six or more hours daily). Less commonly, planting too shallow or cutting foliage back before it yellows naturally can weaken the corm and reduce next year’s bloom.

Do I need to lift Crocosmia corms every year?

Not in zones 7–9 — they overwinter happily in the ground with no special treatment. In zones 6–7, a thick mulch layer (8–10 cm) usually provides sufficient protection. Only lift corms in the coldest areas, exposed gardens, or where your soil is heavy and wet through winter. In well-drained soil, most gardeners leave them in the ground indefinitely and just divide every few years when flowering declines.

Is Crocosmia ‘John Boots’ toxic to pets?

Crocosmia is generally considered non-toxic to dogs, cats, and humans. It’s not listed on the ASPCA’s toxic plants database. That said, ingesting any plant material in quantity can cause mild gastrointestinal upset in pets, so it’s sensible to discourage chewing. The corms taste unpleasant enough that most animals leave them alone.

What’s the difference between Crocosmia ‘John Boots’ and ‘George Davison’?

Both are compact, yellow-flowered Crocosmia × crocosmiiflora cultivars at roughly the same height (around 60 cm / 2 feet). The key differences: ‘John Boots’ has wider-spaced, starry, flat-faced petals in canary yellow with paler centres — a lighter, more open flower form. ‘George Davison’ has more typical funnel-shaped flowers in a deeper orange-yellow (closer to amber), and holds an RHS Award of Garden Merit. Both are excellent garden plants; the choice comes down to whether you prefer the starry or funnel flower form and the paler or deeper yellow tone.

References

1. Royal Horticultural Society. “How to Grow Crocosmias.” RHS Gardening. RHS — Crocosmia ‘John Boots’.
2. University of Florida IFAS. “Crocosmia.” Gardening Solutions.
3. NC State Extension. “Crocosmia.” North Carolina Extension Gardener Plant Toolbox.
4. Gardenia. “Great Companion Plants for Your Crocosmia.”

References

1. Royal Horticultural Society. “How to Grow Crocosmias.” RHS Gardening. RHS — Crocosmia ‘John Boots’.
2. University of Florida IFAS. “Crocosmia.” Gardening Solutions.
3. NC State Extension. “Crocosmia.” North Carolina Extension Gardener Plant Toolbox.
4. Gardenia. “Great Companion Plants for Your Crocosmia.”