Andrew Mangwarara

During the years I have spent gardening, I have come across many plants of different shapes and colours, but very few have the presence of hydrangeas. Any day comes to life when they flower, their popular blue and pink colours are dazzling.

Even more amazing is the fact that sometimes two colours can be spotted on one bloom, thereby creating an intriguing mystery. While hydrangeas or hortensia have always made many gardeners hesitant to try them out, better varieties have emerged through continuous breeding over the years.

They are useful in groupings, pots and as border shrubs.  Most hydrangeas will do well in rich, porous and moist soils. They prefer full sun in the morning and shade in the afternoon, although they will succeed in partial shade.

Start your hydrangeas in spring by digging a hole at least 60 centimetres deep and a metre wide. To plant your specimen, put it in the hole and fill it up with soil halfway. Water the plant. After the water has drained, fill up the hole with additional soil. Water the hydrangeas regularly and thoroughly, particularly during the first two years of establishment. Leaves will wilt if your soil is dry.

For those with good soils, fertilising will not be necessary as it can result in more vegetative growth, which delays flowering. However, fertiliser that is rich in potash can encourage flowering.

Sandy soils will need some fertilising at least once a year at the end of winter or in spring. With some patience, hydrangeas bloom colour can be changed over two years. The bloom colour can be changed easily from blue to pink. However, it is more difficult to change it from pink to blue.

Usually, hydrangea macrophylla and H. serrata can be changed by adjusting soil pH. Acidic soils with a pH below 5, 5 produce blue flowers whilst soils with a higher pH produce pink flowers (7, 5-8). White flower hydrangeas are not affected by soil pH.

Adding some fertilisers like ammonium nitrate or ammonium sulphate can make the soil acidic. Your ordinary tea leaves and peat based composts can also make the soil acidic. Watering lime into the soil will raise pH but be cautious as this can be irreversible. Also, plants in that soil can become chloritic, developing yellow leaves as they will be unable to take up the iron.

Some pruning is essential to remove old dead wood after the flowers have faded in summer. Cut dead wood in late winter or early spring. Cut right to the base of the stem to encourage branching. In the case of old neglected plants, remove all the stems on the plant. This will help rejuvenate the plant. In gardening language, hydrangeas symbolise gratitude for being understood. Therefore next time you resolve some conflict, give the other party a hydrangea as a sign of your gratitude.

As for plant enthusiasts, growing hortensia is a life-long hobby that cannot be easily abandoned as it brings so much satisfaction.

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