Satsuki azalea 'Juko'
IntermediateRhododendron indicum 'Juko'
A satsuki bred from 'Kotobuki' × 'Gyoten'. Medium flowers of pinkish purple with red-purple stripes, white centres or pure white on one plant; both petals and leaves are thick. Esteemed as a classic and parent of many named sports.
About
Juko is a satsuki azalea cultivar bred from 'Kotobuki' × 'Gyoten'. The Japan Satsuki Association records it as registered with the Japan Satsuki Society in 1969 and the Tochigi Satsuki Society in 1971 (growers' society registrations, not under the Plant Variety Protection Act). The flowers are in the purple group: pinkish purple ground with red-purple stripes (jiai) as the base pattern, plus white-centred, plain and white blooms, medium in size. Petals are thick and rounded (one guide calls the form midway between korin and pointed), leaves are thick and medium-sized, and the plant is vigorous, extends well and buds freely. It won the Association's Minister of Agriculture prize and has given many fine sports and crosses: the round-leaved form is 'Osho', the pointed-petalled one 'Juko-no-hoshi', and the white-ground fringed one 'Haru-no-kotobuki'. Used as a parent it often passes on jiai-patterned flowers. Sources disagree on flowering time, some saying early and others late. Among purple medium-flowered cultivars, its thick rounded petals and jiai stripes help identify it. Sold by specialist satsuki growers as young plants and bonsai material.
Size of the Satsuki azalea 'Juko'
The Satsuki azalea 'Juko' grows to Satsuki is an evergreen shrub of about 0.5–1 m; as bonsai it is trained to suit the pot.
Basic Info
Origin
Japan ('Kotobuki' × 'Gyoten')
Lifespan
Little data for the cultivar
Size
Satsuki is an evergreen shrub of about 0.5–1 m; as bonsai it is trained to suit the pot
Temperature
-5〜35℃
Watering & Fertilizer
Fertilizer (April, June after flowering, Sept–Oct)
Growing Tips
Light & placement
Likes light, but summer sun scorches leaves and roots. Give young plants full sun; keep finished trees in part shade, always with good airflow
Watering
Likes water but its fine roots rot if waterlogged: 1–2 times daily in spring, 2–3 in summer, every 2–3 days in winter. Avoid watering in the midday heat
Temperature & overwintering
Reasonably hardy but dislikes cold winter wind; keep the pot from freezing under eaves or similar
Soil & repotting
Coarse, acidic kanuma-based mix. Repot right after flowering (June) or in autumn (late Sep–early Oct)
Fertilizer
Solid fertilizer about April as new leaves harden, after flowering in June, and monthly in Sep–Oct. Underfeeding causes dieback
Pruning & styling
Flower buds form in July to mid-August, so finish pinching and pruning in June (early July west of Kanto). Wire in April and Sep–Oct
Pests & cautions
Especially pest-prone: lace bugs, spider mites, aphids and thrips are common, so regular control is needed in the growing season
Satsuki azalea 'Juko' FAQ
QWhat is the growing difficulty level for Satsuki azalea 'Juko'?
Intermediate. A variety suitable for intermediate growers. Requires some cultivation experience and knowledge of environment management. Pay careful attention to temperature and humidity control.
QHow large does Satsuki azalea 'Juko' get?
The mature size of Satsuki azalea 'Juko' is Satsuki is an evergreen shrub of about 0.5–1 m; as bonsai it is trained to suit the pot. This may vary slightly depending on cultivation environment and individual differences.
QHow should I water and fertilize Satsuki azalea 'Juko'?
Satsuki azalea 'Juko': watering & fertilizer — Fertilizer (April, June after flowering, Sept–Oct). Aim for appropriate frequency and amount.
QWhat is the typical price for Satsuki azalea 'Juko'?
The price of Satsuki azalea 'Juko' varies significantly by variety, characteristics, size, and lineage. Please check GrowerDirect's price guide for the latest market information.
Last updated: September 23, 2026
References & Sources
Edited & verified by: GrowerDirect Editorial Team
The classifications, regulations, and growing data on this page are created and verified based on the primary information database below.
Taxonomy & Authority
Regulations & Conservation Status
Not listed by CITES and not regulated for domestic sale. Not a registered variety under the Plant Variety Protection Act (no entry for 'Juko' in the MAFF database, checked Sept 2026). Its 1969 and 1971 'registrations' were with satsuki societies, not under the Act.
Sources: Species+ (CITES listing search) / MAFF Plant Variety Registration Database
Regulations may change. Always verify the latest information with the relevant authorities.
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