How to Grow Delphiniums

These stunning perennial flower plants are famous for their unique shapes and vivid hues, making them an absolute must-have in your outdoor displays! Despite their immense beauty and sculptural shapes, delphinium plants are surprisingly easy to grow - perfect for newbie gardeners keen to get the whole family involved in creating stunning arrangements in the soil!

So, if you’re wondering how to grow delphinium from seed and how to care for delphinium plants, Fothergill’s has all the information you could possibly need! Take a look at our Delphinium guide today, and look forward to growing delightfully bright blooms in your garden!

Each variety of delphinium enjoys being planted or sown in full view of the sun. You should ensure that the soil is well-draining to avoid waterlogging, particularly during the winter months. Delphiniums are tall plants, so they may need coverage from heavy winds to protect their spires from damage.

If you’re looking to start from scratch, find out how to grow delphinium from seed here. If sowing outdoors, we’d advise you to get your delphinium seeds in the soil between April and June or September and October. And remember, you shouldn’t expect to see your delphiniums flower until the following year.

How to sow delphinium seeds

Sow your seeds thinly over the soil in a container and water them in lightly. Eventually, once your seeds have grown three pairs of leaves, move them into individual pots. This should happen sometime between May and June. If you’ve been growing your seedlings indoors, however, give them the opportunity to harden off outdoors before pricking them out.

Perennials can be planted in a range of ways. Whilst they make excellent border plants, they can also thrive in a 

container with plenty of peat-free compost or fertiliser. 

When to plant delphiniums

Whilst we recommend planting your delphinium plant in the garden between spring and early summer, there is flexibility here. As long as your soil isn’t waterlogged or frozen, your delphiniums should be good to go. Distance your delphiniums around two feet apart in groups of three. This space ensures there’s plenty of room for ventilation and prevents the spread of diseases from plant to plant.

Your delphiniums may be in the ground, but your job as a plant parent doesn’t end here. Discovering how to care for your delphiniums is just as important as learning how to plant them, so listen up!

Watering

Whilst delphiniums cannot thrive in waterlogged soil, they do enjoy moist soil—particularly during the warmer months. To promote growth, keep them watered regularly, especially as they establish. 

Fertilising

Delphinium plants love to be well-fed! So you can give them feeds and fertilisers as often as three times during the summer. We would even recommend adding fertiliser to your plants at the beginning of autumn as their flowers begin to die.

Stalking

Stalking is essential for maintaining the health and appearance of your delphiniums. Wind is the worst enemy of these blooms, so offering them support with stalking can keep them standing tall. Make use of bamboo sticks to create a cage around your delphiniums. Don’t worry - these will essentially be invisible in full borders! 

Overwintering

Whilst delphiniums are hardy perennials and can survive the frost, they struggle in waterlogged soil. We recommend ensuring that your soil is free draining to prevent your flowers from dying during the winter season.

What are you waiting for, gardeners? Now that you’re all caught up on how to care for delphinium plants, it’s time to get to growing! Bring Fothergill’s along on your family’s growing journey and shop our fantastic range of delphinium seeds and plants today! 

If you’ve got any more questions on how to grow delphiniums from seed, feel free to contact us or dig a little deeper into our blog for more growing help and advice!