Blue with a fine signature
A subtle, deeper line runs along each segment of the pale blue flowers, keeping the colour luminous without looking flat.
Agapanthus 'Crystal Blue'® 19cm
Normal price
€20,00
What does the legal guarantee mean for plants?
The legal guarantee concerns the plant’s conformity at delivery. It is not a guarantee of survival or growth for two years. Each issue is assessed taking into account the nature of the plant, its care and the conditions in which it is kept. Your statutory rights remain unaffected.
Agapanthus ‘Crystal Blue’®
Stands tall, flowers beautifully and asks for very little ☀️
- Evergreen perennial
- Full sun
- Summer flowering
- Pots & open ground
Agapanthus ‘Crystal Blue’® lifts luminous pale-blue flower heads above a full green clump, bringing a cool, clear note to the summer garden. A deeper blue line runs through each little flower, adding a detail that rewards a closer look. Slender upright flower stems leave space for light between the blooms, while the long arching leaves give the planting a flowing outline that remains attractive after flowering.
Repeated along a border, it creates a sequence of blue accents above the greenery. In a large pot, its rounded flower heads sit beautifully beside white flowers and silver foliage, making a calm summer composition.
What makes it special
Its distinctive presence comes from the clear blue colour, airy flower heads and the strong architectural base of its foliage.
Flowers that seem to float
Numerous individual flowers gather into rounded heads, held on sturdy stems above the lower green mound.
Structure beyond flowering
Dense, lance-shaped foliage forms an evergreen clump that keeps a clean outline and strong presence beyond the flowering season.
Why you will love it: it adds height, rhythm and summer blue without making the planting feel heavy or formal.
In the garden & on the balcony Placement & plant combinations Where it looks its best and which plants share similar growing conditions
Position & spacing in the border
With a mature height of about 70 cm and a spread of around 50 cm, ‘Crystal Blue’ works best in the middle layer of a deep border or the back row of a shallow one. Place lower plants of about 20–35 cm in front so the flower stems remain fully visible, and use taller shrubs or grasses behind it where they will not block the sun.
Allow 50–60 cm from centre to centre: about 50 cm in groups of three or five for a more unified display, and 60 cm in a mixed border so each clump keeps a clear outline and good airflow. Measure from the centre of one plant to the centre of the next, not from the edges of the pots.
Combinations that work
For a calm scheme, keep the palette to white, glaucous-silver foliage and muted lilac. Choose plants for full sun and free-draining soil; where watering needs differ, place them in separate irrigation zones.
- Oenothera lindheimeri — in white, behind or between the clumps, for airy movement that does not overpower the blue.
- Lavandula angustifolia — to the side, for soft lilac flowers and fragrant grey-green foliage; place it at the drier edge.
- Festuca glauca — low at the front, where its glaucous foliage brightens the blue without hiding the flower stems.
Care at a glance
Light
Full sun encourages sturdy stems and abundant flowering. Introduce a newly purchased plant to strong sun gradually.
Watering
During active growth, water when the upper layer begins to dry, without allowing the pot to dry out completely.
Climate & hardiness
Evergreen in mild conditions. Protect the pot and foliage from severe frost and prolonged cold, wet weather.
Safety
Harmful if eaten by people or pets. Do not allow the leaves or fleshy roots to be chewed.
For this plant
Planting & nutrition
Detailed care Complete care guide Position, planting, watering, winter protection and flowering in detail
Light and exposure
Give it full sun in an open position, preferably sheltered from the strongest winds that can bend the flower stems. If the plant has come from a shaded nursery or shop display, increase its hours of direct sun gradually.
Planting in the ground
Plant in spring at the same depth as it was growing in its pot, in fertile soil that retains some moisture while draining excess water quickly. Avoid low-lying areas where the soil remains saturated in winter.
Potting and repotting
Use a pot with several drainage holes and a loose, peat-free multipurpose compost with improved drainage. Once the roots have genuinely filled the available space, move up by only one moderate size, about 2.5–5 cm wider.
Watering and establishment
While it is establishing and during active growth, water thoroughly when the upper layer of the compost or soil begins to dry. Always allow excess water to drain away; in a pot, do not let the entire root ball dry out completely from summer into early autumn.
Winter and hardiness
‘Crystal Blue’ is listed as evergreen, so its foliage and roots need care during severe frost. In colder areas, move the pot to a bright, sheltered, frost-free position and protect it from prolonged winter rain.
Feeding
In pots, feed regularly but moderately during active growth with a balanced fertiliser formulated for flowering plants, following the label instructions exactly. In the ground, fertile soil often needs fewer additional applications.
Flowering and grooming
The main flowering period is in summer and may continue for longer depending on the climate and the plant’s maturity. Cut spent flower stems at the base, or leave selected seed heads for winter interest, and remove only yellow or damaged leaves.
Division and safe handling
Divide a mature, dense clump in spring only when rejuvenation or propagation is needed; division preserves the cultivar’s characteristics. Wear gloves and keep leaves and fleshy roots away from children and pets, as the plant is harmful if eaten.
Development over time How it develops in the garden What to expect in the ground and in a pot as the plant matures
A clump that fills out over time
‘Crystal Blue’ is not a one-season plant. Its base gradually becomes denser and, as it establishes, develops a fuller presence and may produce more flower stems.
In the ground
In a border, it has room to develop into a broader, fuller clump. Once established, it remains a reliable perennial feature and begins a new cycle of growth and flowering each year.
In a pot
In a pot, growth remains more controlled and the clump thickens within its boundaries. As it matures, the contrast between the compact green base and tall flower stems becomes more pronounced.
Mature habit & dimensions
2–5 yearsHeight 70 cmSpread 50 cm
Total height includes the flower stems.
Form through time
SummerFlowers above the arching clump.
WinterFoliage remains in mild conditions.
Seasonal timing varies with climate and the age of the plant.
What to expect after planting: During its first season, it may invest more energy in establishing roots than in maximum flowering. The characteristic full appearance of ‘Crystal Blue’ develops as the clump settles and matures in its position.
History & origin Cultivar origin ‘Crystal Blue’ in Allplant’s production
Dutch producer Allplant supplies nurseries with Agapanthus ‘Crystal Blue’® as tissue-cultured young plants. This selection has pale-blue flowers with a darker central line along the tepals.
Allplant’s involvement concerns its propagation; the original raiser, parent pair and selection year have not been published.
Greenleaf for Plant Nerds Science nobody asked for Botanical details for anyone curious about what lies behind the plant’s appearance
Six tepals in two whorls
Each flower has six similar perianth segments arranged in two sets of three. They are called tepals because they are not clearly differentiated into green sepals and contrasting petals. In ‘Crystal Blue’, the darker central line makes their arrangement especially easy to see.
A rhizome bears buds
The clump has short fleshy rhizomes: modified stems bearing buds that produce new leafy shoots. They are not simply swollen roots. This structure allows the clump to become denser around its original base.
Frequently asked questions
Useful answers about sunlight, planting, watering, flowering, winter care and Agapanthus safety.
01 Does it really need full sun?
Yes. Full sun supports more abundant flowering and sturdier stems. If the plant was previously kept in a shaded nursery or shop, increase its exposure to direct sun gradually so the foliage can acclimatise.
02 Is it better in a pot or in the ground?
It suits both. In the ground it needs a sunny position that does not become waterlogged, while a pot gives you greater control over drainage and makes protection during severe frost easier. Avoid both an oversized pot and permanently congested roots.
03 When does it need watering?
During active growth, water when the upper layer begins to dry and continue until the entire root ball is evenly moistened and excess water drains away. Do not wait for the pot to dry out completely in summer, and do not follow a fixed number of days.
04 Why is it not flowering?
Common causes include insufficient sunlight, allowing the pot to dry out completely in summer and early autumn, excessive division, exhausted roots or inadequate winter protection. A recently divided plant may also need time before it flowers abundantly again.
05 Does it need winter protection?
In mild areas it can remain outdoors in a sheltered, free-draining position. Where severe frost occurs, protect the pot and evergreen foliage carefully or move it to a bright, frost-free place. Cold combined with saturated compost is more dangerous than cold alone.
06 Is it safe around pets and children?
No. Agapanthus is harmful if eaten by people, dogs or cats. Keep it out of easy reach, wear gloves when dividing or cutting the plant, and wash your hands after handling it.
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Every order is prepared with care so your plant arrives upright, secure and safe.
Individual protection
Plants in pots with a capacity of 3 litres or more are placed in individual boxes that hold the pot securely and reduce the risk of tipping over.
Sturdy packaging
We use reinforced cardboard designed to protect against impacts and vibration during transport.