Rhododendron 'Shamrock'
Hybrid rhododendron
Also known as Rhododendron ferrugineum 'Shamrock', Rhododendron 'Shamrock' Alpine
- Height × spread
- 1.5m × 1.5m
- Position
- Part shade
- Hardiness
- Very cold to -20C (RHS H6)
- Flowers
- Spring
Availability
Generally available in Autumn, Winter & Spring
Many plants are seasonal. Call 01234 567890 to check current stock.
About this plant
This has intriguing near Chartreuse green flowers, densely borne during April and May. The flowers are carried in dense though small trusses. The flowers have some yellow spots on their surface, but these are only noticeable when closely observed. This makes a spreading shrub that enjoys a sheltered site with acidic soil. It stands around 1.5 metres in height with a 3 metre spread when mature.
- Flower colour
- Green
- Foliage colour
- Green
- Variegated
- No
- Scent
- No
- Shape
- Round
- Height
- 1.5m
- Spread
- 1.5m
- Height in 10 years
- 0.75m
- Spread in 10 years
- 0.75m
- Season of interest
- Spring
- Flowers in
- Spring
- Evergreen
- Evergreen
- Sun or shade
- Likes part shade, tolerates light shade
- Soil type
- Loam (normal)
- Soil pH
- Acid (ericaceous)
- Drainage
- Moisture retentive soil, Damp and wet soil, Well drained soil
- Hardiness
- Very cold to -20C (RHS H6)
- Borders & containers
- Borders
- Use for
- Structural, Deer resistant, Rabbit resistant
- Hazards
- Yes, potentially harmful; Humans: Harmful if eaten
AutumnNow
Autumn · Outdoors
Apply mulch
Use bark chips or leaf mould to add an organic mulch around the crown of the plant.
A mulch is a covering that can: protect the soil surface from rain, heat and cold; deter weeds; provide nutrients. Organic indicates that material has vegetative origin e.g. manure, compost. Synthetics i.e. plastics, or stones are often called mulches.
Spring
Spring · Outdoors
Apply acidic mulch
Where soil is only just acidic, apply mulch with a high acidic content such as leaf mould, or mulch for ericaceous plants. Alternatively the plant can benefit from a feed of iron supplement (iron chelate) such as sequestrol.
Spring - late · Outdoors
Feed with slow release fertiliser for ericaceous plants
Apply a slow release fertiliser for ericaceous plants before applying any mulch, spreading it around the root area of the plant as it is coming into growth. (Or apply a liquid feed at regular intervals throughout the growing season.)
This is a simple way to provide a nutrient boost as a single annual procedure.
Spring-Autumn · Outdoors
Water to keep the soil moist
For best results, this plant needs soil that is always moist. Water deeply and regularly as soon as soil appears dry. Even for established plants in the ground, a dry week can cause problems with some soils. Check plants in pots more often, especially in hot weather. Or install an automatic irrigation system which will do the hard work for you, even when you are away on holiday.
Without regular watering some plants never fully regain their beauty.
Planting & general
Outdoors
Water with rain water
This plant needs rain water or soft water (the minerals in alkaline or "hard" water are harmful). This is especially important for plants in pots.
Outdoor planting · Planting
Add root growth stimulant to the planting hole
Mycorrhizal fungi helps roots establish quickly, so they absorb water and nutrients more efficiently. It comes as a powder, granule or gel. Add to the planting hole or container, and to the plant's rootball before planting in the hole. For "bareroot" plants use a gel.
Planting
Deadhead blooms during flowering season
Remove flowers as they turn brown and fade. Snip the stem just below the bloom. This will keep the plant tidy and encourage more flowers.
The removal of spent flowers encourages the plant to produce fresh ones, rather than spend its energy on the development of seeds.
Compost · Planting
Ericaceous compost
Plants such as Camellia, Azalea and Rhododendron need acidic (ericaceous) soil. Where the soil is not acidic, or when planting in pots, use an ericaceous compost, or specialist compost for Camellia, Azalea and Rhododendron.
Found in
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