Grow hydrangeas for a stunning burst of colour

Growing hydrangeas is a bit like having slow-motion fireworks in your garden as the flowers burst into life. And you can change flower colour, depending on the soil they’re planted in!

February 17, 2022

Choose a spot in the garden that attracts morning sun with well-drained soil. Enrich the soil with a soil improver and plant fertiliser.

  1. Dig the planting hole twice as wide and to the same depth as the root-ball. Remove the shrub from the container, gently tease the roots and cut away any circled or tangled roots.
  1. Position in the hole and back fill with soil, gently firming down.
  1. Form a raised or doughnut shaped ring of soil around the outer edge of the plant’s root zone. This helps keep water where it’s needed. Always water in well after planting to settle the soil around the roots and keep the soil moist for several weeks while the new plant establishes.
  1. Mulch around the base with organic mulch such as wood chips or pea straw, keeping it away from the trunk.
  1. Feed every week through spring and summer with liquid plant food.
  1. Most hydrangeas prefer a semi shade to full shade position in the garden with rich well drained soil. Don’t let them dry out, or they will wilt.

Pots

Growing hydrangeas in pots is easy and you can move them around to get the best position.

Choose a pot at least 50 cm wide. Remove the shrub from the container, gently tease the roots and cut away any circled or tangled roots.

  • Position in the pot and gently firm the soil down. Water well.
  • Feed every week through spring and summer with a liquid plant food.

How to change the colour of your hydrangeas

If you fancy a colour change in your garden, you can change pink hydrangeas to blue, and blue hydrangeas to pink (white will always be white).

It’s all to do with the pH level of your soil, so grab a soil testing kit from the local hardware store.  

For blue hydrangeas, the soil should be acidic and have a pH level between 5.2 and 5.5. To increase the acidity of the soil, add iron sulphate or a soil acidifier near the base of the plant.

For pink hydrangeas, a pH of 6.0 to 6.2 is ideal. Fertilise with high nitrogen and high phosphorous fertiliser.

Hydrangea ‘bluing’ and ‘pinking’ products are also available. 

Gardening