Hydrangea Macrophylla is a hardy shrub that creates magnificent flower of blue, pink and white during Spring and Summer.
Water daily in Spring and in Summer put pot in water to cover compost until bubbles stop rising from root ball. In Autumn and Winter water only when compost appears dry. Use lime free water.
Feed weekly in Spring and Summer. Add liquid house-plant food to water in a bucket using dose as recommended. Drain excess back into the bucket when plant is watered and keep mixture for next feed. Change every 6 weeks.
Re-pot every year before flowering. Place plenty of drainage material in pots. Older plants which are growing in large containers need not be re-potted each year, instead remove the loose compost and top dress with a fresh mixture with extra fertilizer added.
Cuttings from non flowering stem in late Summer with 2 pairs of leaves can be rooted in gentle heat in a propagator.
Keep plant in a semi shade, well ventilated cool room from Autumn to late Spring, then a sheltered place outdoors is ideal.
Cut back the old flower stems as the colour fades. Plants being kept in their pots for growing indoors or on the terrace should be pruned back in early Autumn. Keep on the dry side and protect from frost over Winter.
The acidity of the compost influences the colouring of pink and blue varieties. Pink can be make blue by using acid compost by adding aluminium sulphate to the soil, which has to be applied every week from the moment the buds begin to show in Spring. While blue ones may be changed to pink by adding of iron.
Hydrangea is well suited to grow in pots in the home and will grow in the garden when flowering period is over. Provide protection for the crowns in Winter by heaping up compost around them.
They are superb on patios, terraces and verandahs.
Spray daily with soft water in Spring and Summer.
Lime free compost.
Watering is necessary when transplanting, but be careful not to over water.