Name: ‘Rhubarb Custard’ Collarette Dahlia
Brand: Van Noort
SKU: VAN-327-406-65
Price: 13.99 CAD
Availability: InStock

Sale Sold out

Upright Rhubarb Custard dahlia clump reaching 100 cm

Bulb Asteraceae

Van Noort

Dahlia pinnata

From bulb to bloom

Common nameRhubarb Custard collarette dahlia

FamilyAsteraceae

GenusDahlia

SpeciesHybride horticole à collerette

CultivarRhubarb Custard

Bulb typeTubercule de dahlia à collerette

Botanical nameDahlia

Quantity per pack1 tubercule

Bulb sizeNo 1

‘Rhubarb Custard’ Collarette Dahlia (Dahlia × hortensis) creates an especially refined open flower. A ring of broad soft-apricot petals surrounds a rhubarb-red band, while twisted creamy collar petals tipped with lavender frame the central disc. Flowerheads approximately 11 to 13 cm across appear abundantly on an upright clump that can reach about 100 cm. Bred by Keith Hammett in New Zealand and associated with the Sweet Candy Series, this productive cultivar energizes borders and arrangements from midsummer until the first frost. Its accessible centre also welcomes more insects than a fully double dahlia. The intricate palette remains easy to coordinate with warm or pastel companion flowers.

Plant the tuber in spring after the final frost once soil is warm, fertile, rich in organic matter, and freely drained. Lay it approximately 10 cm deep with the eye facing upward in a position receiving at least six hours of sun, then reserve 50 cm around the crown. Install support at planting for the long stems. Water sparingly before emergence, then deeply at soil level whenever the top few centimetres begin to dry. Pinch shoots near 30 cm to multiply branches. Mature compost and moderate fertilizer containing more potassium than nitrogen support flowering, while excessive nitrogen creates soft stems and too much foliage. Avoid standing water and repeated overhead irrigation.

Place Rhubarb Custard near a path where its successive apricot, red, cream, and lavender rings can be examined. Chocolate cosmos, blue salvias, white gauras, and bronze grasses reinforce the palette without hiding the collar. Harvest fully open stems early in the morning and remove fading blooms regularly to extend bud production. Disc florets can supply pollen and nectar to bees and other insects; keep nearby simple flowers to diversify resources. Watch for slugs, aphids, earwigs, and spider mites while maintaining generous airflow. After the first frost in cold Canadian climates, lift the tuber, dry its surface, label it, and store it somewhere cool, dry, dark, and frost-free. Inspect stored material monthly until spring.

Light and life cycle

In the garden

Exposure: Full sun
Life cycle: Perennial
Hardiness: Zone 10

Planting and establishment

Planting guide

Planting & establishment

Planting depth

10 cm (4 po)

Spacing / density

50 cm (20 po) entre les plants

Establishment temperature

Sol à environ 16 °C ou plus

Rooting time

Quelques semaines, selon la chaleur et les conditions de culture

Planting period

Printemps, après les derniers gels

Propagation

Division of tubers, each retaining a viable bud

Growing method

Plantez au printemps en sol réchauffé, au soleil, dans une terre fertile et drainée. Arrosez régulièrement après la levée et retirez les fleurs fanées. Déterrez la souche après le premier gel pour la conserver hors gel.

Soil and care

Soil & care

Soil pH

Slightly acidic to neutral

Moisture

Sol frais pendant la croissance, sans eau stagnante.

Minimum temperature

5 °C (41 °F)

Care level

Moderate

Watering

Régulier pendant la croissance, sans détremper le sol; arrosez au pied lorsque la surface sèche.

Soil type

Fertile, meuble et bien drainé

Fertilization

Incorporate mature compost before planting. During early growth, use balanced fertilizer low to moderate in nitrogen, then favour higher potassium when buds appear. Follow the labelled rate and water afterward. Excess nitrogen encourages foliage at the expense of flowers.

Seasonal care

In spring, inspect the tuber and plant it after the final frost once soil has warmed. Water sparingly until emergence. In early summer, pinch the shoot at approximately 20 cm to form a branching clump, then maintain even moisture without saturation. As buds appear, feed moderately with a formula richer in potassium. During flowering, water deeply at soil level in dry weather, remove faded heads continuously, and watch for slugs, aphids, and spider mites. Maintain open airflow around the foliage. After the first frost blackens the leaves, cut the stems, lift the tuber carefully, and allow its surface to dry in a ventilated place. Label Rhubarb Custard, then store it in darkness somewhere cool, dry, and frost-free. Inspect it monthly and remove only tissue showing active rot. Full sun encourages sturdy stems and an abundant display of multicoloured flowers. In colder Canadian regions, store the tuber somewhere cool, dry, and frost-free through winter. Generous airflow helps the foliage dry quickly after rain.

Growing in containers

Container growing

Recommended pot size

Container at least 40 cm (16 in.) wide and deep

Choose a stable 40 to 50 L container that is deep and fitted with several drainage holes. Fill it with a rich yet airy growing mix, then plant one tuber 10 cm deep. Keep the pot in full sun with shelter from strong gusts. Water sparingly before emergence, then thoroughly whenever the upper few centimetres of mix dry; always empty the saucer. Pinch the young shoot to encourage branching and apply moderate liquid feeding richer in potassium from bud formation. Rotate the container weekly to maintain balanced growth. Remove faded flowers to extend bloom. Before frost, move the pot under cover or lift the tuber for storage somewhere cool, dry, and frost-free. Full sun encourages sturdy stems and an abundant display of multicoloured flowers. In colder Canadian regions, store the tuber somewhere cool, dry, and frost-free through winter. Generous airflow helps the foliage dry quickly after rain.

Growth and flowering

Size, flowering & harvest

Mature height

Environ 100 cm

Width / spread

Environ 50 cm

Flower color

Soft apricot, rhubarb red, cream, and lavender tips

Foliage color

Dark green

Foliage type

Deciduous

Growth rate

Fast

Growth habit

Touffe dressée

Fragrance

Parfum non marqué

Bloom period

Flowering generally begins in midsummer and continues until the first frost. Pinch the young shoot to encourage branching, remove faded blooms regularly, and harvest stems when flowerheads are fully open. Full sun and moderate feeding support a sustained display.

Harvest

July to October. Cut fully open flowers for the best vase life.

Garden companions

Garden associations

Companion plants & uses

Companion plants

Pair Rhubarb Custard with blue salvias, violet verbenas, white sweet alyssum, gauras, catmint, and compact grasses. These plants echo the layered palette without hiding its upright habit and extend resources for pollinators. Avoid very dense neighbours or plants that require constantly saturated soil.

Other recommended plants

Associez-le à des sauges bleues ou à des cosmos blancs dans un massif ensoleillé.

Garden use

Place Rhubarb Custard in the middle of a border or beside a path where its collarette flowers remain easy to appreciate. Repeat two or three plants with 50 cm between crowns to create a apricot-and-rhubarb rhythm without restricting airflow. Pair it with blue salvias, violet verbenas, white sweet alyssum, or fine grasses. In a small courtyard, grow one tuber in a stable container and rotate the pot weekly for balanced growth. Remove faded blooms to renew buds, while leaving several fresh flowerheads open for bees and butterflies. Keep the base accessible in autumn because the tuber must be lifted and stored frost-free in colder Canadian regions. Full sun encourages sturdy stems and an abundant display of multicoloured flowers. In colder Canadian regions, store the tuber somewhere cool, dry, and frost-free through winter. Generous airflow helps the foliage dry quickly after rain.

Frequently asked questions

When should Rhubarb Custard dahlia be planted?

Plant the tuber after the final frost once soil has warmed and no longer stays waterlogged. Choose full sun and fertile, humus-rich, freely drained ground. Lay the tuber horizontally 10 cm deep with the bud facing upward, leaving 50 cm around the crown. Water very sparingly before emergence to reduce the risk of rot. Once stems are established, water deeply at soil level whenever the surface dries. In a cold region, you can start the tuber in a container several weeks earlier, then gradually acclimatize the shoot before setting it outdoors.

Do Rhubarb Custard flowers attract pollinators?

Yes. Unlike highly double dahlias, Rhubarb Custard bears collarette flowers with an open central disc. Bees, hoverflies, and butterflies can therefore reach pollen and nectar directly while flowerheads are fresh. Place the plant in sun and avoid spraying pesticides on the blooms. Leave several flowerheads open during the day, then remove them after fading to encourage new buds. Combine sweet alyssum, salvias, verbenas, or other single flowers to provide complementary resources before and after the dahlia’s main flowering periods.

How can Rhubarb Custard flowering be extended?

Pinch the young shoot at approximately 20 cm to encourage several branches and more buds. Water deeply at soil level whenever the surface dries, then allow excess moisture to drain. Incorporate mature compost before planting and use moderate fertilizer richer in potassium once buds form. Avoid excessive nitrogen, which produces abundant foliage at the expense of flowers. Remove faded flowerheads regularly before seeds develop. In a very exposed position, shelter the clump from strong winds so the flowering stems do not lean or break.

Can Rhubarb Custard grow in a container?

Yes. Choose a stable 40 to 50 L container that is deep and fitted with several drainage holes. Fill it with a rich yet airy growing mix, then plant one tuber 10 cm deep. Set the pot in full sun with shelter from strong gusts. Water sparingly before emergence, then thoroughly whenever the upper few centimetres of mix dry, without leaving water in the saucer. Apply moderate liquid feeding richer in potassium from bud formation. Rotate the container weekly and remove faded blooms to maintain balanced growth and a steady display.

How should Rhubarb Custard be overwintered in colder Canadian regions?

After the first frost blackens foliage, cut the stems while leaving a short section. Lift the tuber with a fork, working far enough from the crown to avoid injury. Gently remove excess soil, allow the surface to dry in a ventilated place, and label Rhubarb Custard clearly. Store the tuber in darkness somewhere cool, dry, and frost-free, using a lightly insulating material that limits shrivelling without holding water. Inspect it monthly and remove only sections showing active rot. Plant it again after the final frost once soil has warmed.

Wildlife and pets

Wildlife & precautions

Reported toxicity

Yes

Supporting wildlife

Collarette flowers with open discs give bees, hoverflies, and butterflies direct access to pollen and nectar. Avoid pesticides on flowerheads and add other single flowers to extend seasonal resources.