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Hydrangea macrophylla 'Kardinal Violet'
hydrangea
Noted for its abundance of larger than average flowers, which are a rich reddish purple when grown on acidic soils, or...
2 litre pot
available to order from autumn
1
Delivery options
Plant description
Noted for its abundance of larger than average flowers, which are a rich reddish purple when grown on acidic soils, or pinker in soils with a neutral or alkaline pH. One of the new breed of hydrangeas, Hydrangea macrophylla 'Kardinal Violet' often blooms throughout summer and well into autumn.
On alkaline soils the flowers may become pink, and our plants will arrive with pink flowers if purchased during their early budding or flowering period due to the nature of our peat-free compost.
Hydrangeas give their best blue flowers on acidic soils with a pH of 5.5. When grown on neutral soil (with a pH of 7), the flowers will predominantly be pink, although you may also get blue or mauve blooms. If you want to make sure that your hydrangea has blue-toned flowers, you will need to make sure your pH does not creep above 6.5. To lower the pH on a neutral soil, you can treat it annually with aluminium salts. It's much harder however to alter the pH of limey (alkaline) soil, so it's much easier to grow white or pink hydrangeas instead.
On alkaline soils the flowers may become pink, and our plants will arrive with pink flowers if purchased during their early budding or flowering period due to the nature of our peat-free compost.
Hydrangeas give their best blue flowers on acidic soils with a pH of 5.5. When grown on neutral soil (with a pH of 7), the flowers will predominantly be pink, although you may also get blue or mauve blooms. If you want to make sure that your hydrangea has blue-toned flowers, you will need to make sure your pH does not creep above 6.5. To lower the pH on a neutral soil, you can treat it annually with aluminium salts. It's much harder however to alter the pH of limey (alkaline) soil, so it's much easier to grow white or pink hydrangeas instead.
Eventual height & spread
Flowering period
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
Plant features
Position
Light shade
Rate of growth
Average
Soil
Moderately fertile, moist, well-drained soil
Hardiness
Fully hardy
How to care for Hydrangea macrophylla Kardinal Violet:
Hydrangea thrives in moist, well-drained soil enriched with organic matter, making it important to improve the soil before planting by adding well-rotted compost or manure.
Choose a spot with partial shade, as full sun can scorch the leaves, especially in warmer climates, while deep shade may reduce flowering.
Regular watering is essential, particularly during dry spells, as these plants dislike drying out. To keep the soil cool and retain moisture, apply a layer of mulch around the base in spring, being careful not to let it touch the stems.
Pruning should be done with care. In early spring, remove any dead or damaged wood, but leave the old flowerheads on over winter to protect the buds below from frost.
For mophead and lacecap species, only prune back to the first pair of strong buds beneath the old flowers, as these types bloom on old wood. If necessary, remove one or two older stems down to the base to encourage new growth, but avoid cutting back the entire plant.
Fertilise in spring with a balanced feed, and for cultivars with colour-dependent blooms, test the soil pH. Adding hydrangea colourant (iron and aluminium salts) can enhance blue flowers in acidic soil, while lime can encourage pinker tones in alkaline conditions. It is best to choose according to the predominant soil conditions for best results on colour.
Choose a spot with partial shade, as full sun can scorch the leaves, especially in warmer climates, while deep shade may reduce flowering.
Regular watering is essential, particularly during dry spells, as these plants dislike drying out. To keep the soil cool and retain moisture, apply a layer of mulch around the base in spring, being careful not to let it touch the stems.
Pruning should be done with care. In early spring, remove any dead or damaged wood, but leave the old flowerheads on over winter to protect the buds below from frost.
For mophead and lacecap species, only prune back to the first pair of strong buds beneath the old flowers, as these types bloom on old wood. If necessary, remove one or two older stems down to the base to encourage new growth, but avoid cutting back the entire plant.
Fertilise in spring with a balanced feed, and for cultivars with colour-dependent blooms, test the soil pH. Adding hydrangea colourant (iron and aluminium salts) can enhance blue flowers in acidic soil, while lime can encourage pinker tones in alkaline conditions. It is best to choose according to the predominant soil conditions for best results on colour.
Please note:
This shrub is deciduous so it will lose all its leaves in autumn, then fresh new foliage appears again each spring.
Warning
Humans: Skin allergen; Pets: Harmful if eaten
