Grown for the flowers Delphinium plants are an erect perennial, from low growing ‘dwarf’ cultivars at around 20cm through to to 2m tall plants depending on species.
How To Grow Delphiniums – Basic Care
Delphinium plants like a moist humus rich soil and as with all soil preparation this is best done a few weeks before planting. Weed the area well and dig in some well rotted compost and cow manure, add a handful of blood and bone and dig over again. Leave for a few weeks and then you are ready to plant.
Usually grown from seedlings or seeds, and are best planted out in early autumn, seeds can be sown in a cold frame to get a head start. Established plants can be divided as clumps expand, this is best done in late winter to early spring. Check the variety as some are taller growing than others and may be best planted further back in the border.
The varieties grown most widely found for sale for the home garden are the taller growing varieties, these delphiniums require full sun with some shade from the hot afternoon sun, a moist humus rich soil and delphiniums may require staking.
Flower colors are whites and blue, through to pink and deep pinks.Used widely in cottage garden borders we include Dowdeswell’s delphiniums from Tesselaar Bulbs.
How To Plant Delphiniums
Delphiniums are best planted where they get morning sun and afternoon shade.
- Prepare the soil before planting. We dig in some well rotted compost, aged cow manure and some blood and bone (bone meal). Dephiniums are hungry plants and dole fertiliser.
- A well drained soil is essential, so raise up the garden bed in damp soils.
- Spacing and Support
How far apart to plant Delphiniums is debatable. The closer they are are together, the taller they grow. Taller plants can be a little weak and fall over, however if you stake them they will survive.
We plant them at around 70 cm apart and stake them with bamboo canes. Some growers plant them so that they grow through a wire mesh for support. We find the stakes are easier.
After Planting
- Mulch around the plants to maintain a cool root run.
- After flowering, remove the spent flower head to just above the ground level.
- In winter cut them back to the ground.
- In spring as new growth appears, fertilise and water as required.
- Fertilizer, Pests and Support
Fertilize with with a liquid seaweed fertilise as well a ‘worm castings tea’ every two weeks. Plants can be cut back after flowering to encourage a second flush, although some growers think that this decreases flower vigor the next year. Taller growing cultivars may require plant supports. The main pests are snails and slugs especially with the small seedlings.
Top Tips
- Flowering from spring through to summer, the actual flowering period will depend on the climate zone.
- When the flower spikes begin to appear it time to fertilise with a liquid organic fertiliser and to keep the plants well watered. Mulch around the base of the plant will provide the cool moist rot run that they love.
- Delphiniums are a perennial so they will die back over winter and reappear in spring as the weather warms.
- Grown for the attractive flowers the appear on tall spikes flower colour varies from white through to red, purple and the trademark blue. Green flowering types are also available.
- Plant them where the receive around 7 hours of sun, morning sun is best in hotter climates, when the flowers on the first spike fade, you can prune back the flower spike down to where the smaller suckers or side shoots appear. These will prove a second flush of flowers, smaller spike, but still very attractive flowers.
Delphiniums v Larkspur
Delphiniums and ‘Larkspur’ are often confused, they are related, however ‘Larkspur’ are actually Consolida species. Delphiniums are perennials, Consolida are annuals.
Where To Buy
357 Monbulk Road SILVAN VIC 3795
Guaranteed "garden worthy" bulbs, plants and perennials. Visit the website to browse our large range of daffodils or request the latest free catalogue.
www.tesselaar.net.au
470 Monbulk-Silvan Road Monbulk VIC 3793
"Guaranteed mail order flowering bulbs, perennials, roses, trees, landscaping plants, garden accessories and community fundraising Austra lia-wide."
www.gardenexpress.com.au
'Umbango' 750 Humula Rd, Humula NSW 2652
Phone 0408692773 Great Range of Perennial plants available for sale by mail order.
www.nutshellnursery.com.au
PO Box 7040 Leura NSW 2780
Rare woodland plants, Trilliums Epimediums, Arisaemas, plus much more.www.lynnsrareplants.com.au
692, Brunswick Rd Wanganui New Zealand
email: terry@delphinium.co.nz
New Millennium Delphiniums, New Zealand Hybrid Delphiniums – photos, cultivation notes and the opportunity to buy seed for these glorious English hybrid type elatum delphiniums.
When to Divide Delphiniums
The best time to divide delphiniums is early spring, just as new growth begins to emerge. This timing minimizes transplant shock and gives the divisions a full growing season to establish. Avoid dividing in late summer or fall, as this can stress the plant before winter dormancy.
Why You Should Divide Delphiniums
- Rejuvenates older plants
- Improves air circulation and reduces disease risk
- Encourages stronger, more abundant flower spikes
- Expands your garden with healthy new plants