Azaleodendron Martha Isaacson

An attractive plant with slightly fragrant white flowers that are striped pink. It is vigorous and is a rare cross of a rhododendron and azalea. Flowering in May, it has unusal evergreen foliage that is tinged deep maroon. Height 150cm in 10 years.

• Recommended for fragrant flowers and sun tolerance
• Plantsman range.
• Group: Azaleodendron.
• Parentage: occidentale X 'Mrs Donald Graham'.
• Hybridization date: pre 2000 (1961).
• Bred by: E. Ostbo. Origin: American.
• Habit: upright.
• Ideal position: Most garden situations, will tolerate some sun.
• Ideal soil: pH 4.5 to 6.
• RHS Hardiness Rating: H5. 
• How we usually propagate this plant: Cutting.
• Awards: AGM until 2013.

Good to know

Azaleodendrons are a group of hybrids between deciduous azaleas and evergreen rhododendrons. They are rarely offered elsewhere, but are generally fully hardy semi-evergreen shrubs which flower in late spring and early summer, sometimes delightfully scented. Azaleodendrons are quite variable, with some looking fairly compact in habit and like an evergreen azalea, and others more upright in habit and nearly bare in winter, like a deciduous azalea.

All require good moist ericaceous soil with a high organic content. For a guide to plant spacing, use the height we give in 10 years as a guide to the distance between each plant. Plant no deeper than the top of the rootball, and dig in plenty of good ericaceous compost around the sides. A teaspoon of slow release feed is sufficient for a 3 litre plant, rising to a small handful for a mature plant.

For further advice, For further advice, see here

The Basics

Ideal soil

Acidic soil, good organic content, pH 4.5-6.0. Inkarho range of rhododendrons will tolerate soils up to pH7.5

Sun or Shade

Light dappled shade is best for most varieties.

Shelter

Refer to hardiness rating. Give young plants protection.

Site Selection

Avoid close to trees, roots, invasive weeds, walls, hot patios, dry banks and waterlogged soils. Do not use weed matting or stone mulch.

Plant spacing

Use the height shown in 10 years as a guide to the distance between each plant. Allow room for plant to fill out. If planting closer for instant impact, be prepared to move plants after a few years.

Compost

• 3 litre pot, dig in 10-20 litres of ericaceous compost.
• 7.5 litre pot, dig in 20-30 litres of ericaceous compost.
• 70-80cm specimen, dig in 60 litres of ericaceous compost.
• 100-120cm specimen, dig in 120 litres of ericaceous compost.

Planting depth

Plant high in the ground, with the top of the rootball visible.

Feeding

Slow-release ericaceous feed recommended in March and straight after flowering.

Mulch

Recommended every few years.

Water

The key ingredient! Keep moist all season, especially the critical time at end of June for flower bud initiation. Tap water is better than no water. Heavy dose at least once per week in dry weather.

Drainage

Ensure good drainage in winter, especially with yellow flowering varieties. Avoid waterlogged sites.

Pruning

Rhododendrons and Camellias: Not normally required. Tidy wayward shoots after flowering.

Evergreen azaleas and Bloombux can be clipped into a low hedge.

Magnolias and Acers: Formative pruning when young to shape into a tree or bush.

Deadheading

Remove old flower-heads, particularly on young or weak plants.

For further advice see here

Size Guide

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