How to grow herbaceous perennials

It’s the season to be planting herbaceous perennials – think delphiniums, ground cover clematis and iris. These glorious plants will give you great colour and interest in your outdoor space. Here are a few tips to make sure you get the best out of them. It’s important to select plants that are suitable for your soil type and garden conditions. Think about where you want to plant them and consider factors like sunlight exposure, moisture levels, and space available. Once you have decided, then it’s time to get planting!

Soil Preparation

  • Test your soil to determine its pH and nutrient levels.
  • If need be, use compost to get the right type of soil
  • Ensure you have good drainage to prevent waterlogging


  • Spring is a great time to plant them as the soil is manageable and temperatures are warmer
  • Dig a hole slightly larger than the plant’s root ball and place it at the same depth as it was in the container
  • Space plants according to their mature size and remember to take into account their spread!


  • Keep the soil consistently moist but not waterlogged, especially as the plant is initially bedding in
  • Water deeply and infrequently to encourage deep root growth.
  • Mulch around the base of plants to retain soil moisture and suppress weeds

Maintaining healthy growth

  • Regularly monitor plants for signs of stress, pests, or diseases
  • Deadhead spent flowers to encourage continuous blooming and prevent self-seeding
  • Divide overcrowded perennials every few years to maintain healthy growth and prevent them from becoming too congested


  • Apply a balanced, slow-release fertilizer in spring to promote healthy growth
  • Avoid over-feeding, as excessive nutrients can lead to lush foliage but fewer flowers

Winter Care

  • Mulch around the base of plants in late autumn to protect them from freezing temperatures
  • Cut back dead foliage in late autumn or early spring to tidy up the garden and prevent disease


  • Lots of herbaceous perennials can grow very tall. Make sure you have stakes or cages for tall or to prevent them from bending or breaking under their own weight

Enjoy the benefits of your labour!

  • Sit back and enjoy the beauty of your garden throughout the growing season and take time to observe pollinators and other wildlife that are attracted to your garden.