how to  ⏵  Delphiniums


Your delphiniums have just started to burst into growth and are ready for immediate planting. 

Once planted, they will quickly take hold, form strong new roots and healthy green foliage.
Some delphinium varieties start growth earlier than others and so don't be concerned if some of your plants look more developed than others.  This is a natural variation in plant growth and will even itself out over the season.

Here are some tips and tricks to help you to get the best results from your plants.

Full sun preferred but successful in up to 50% shade.
Delphiniums are very hardy and tolerant of frosts. They will stand and even benefit from winter freezing.
Permeable shelter (tall loose shrubs or small trees) is required.

Must be rich as delphinium are gross feeders. Mulch and sheep manure work wonders.
PH neutral 6.5-7.0 but successful over a wide range.
Well drained, particularly in warm areas.
Delphiniums must not get warm, very wet feet.
Keep as cool as possible with thick mulch (sawdust also helps prevent slug and snail attack).

Plant in raised beds in Spring  and Autumn
Space each delphinium 1/2m to 1m apart. Wide spacing helps control height, with close spacing plants will grow taller.
Put slug pellets on the ground

Keep young plants moist.
Staking is essential for best results.  If grown in a bed, grow through raised, wide netting or other framework. Properly supported delphiniums will stand a lot of wind.
Don't plant right up against a wall - the wind will thrash them.

Plant Maintenance
After flowering, cut each flower spike down to 5 cm above ground, reduce water, gradually increasing again when new growth begins.
Cut down and tidy in mid-winter, put slug bait down and mulch.
Start feeding again when new growth is 5-10cm high.

Water well when in full leaf and growth is rapid. take care not to over water when cut down after flowering, but increase water again when new shoots are 5-8cm high.

Powdery Mildew can be a problem and regular spraying with sulphur, backed up with a systemic fungicide in hot humid weather, should keep them clean.
You can use the same spray as you do for roses successfully for disease control.

Slugs and snails are the only major pest - use slug pellets to control these especially when plants are small and during winter.

Thanks to Dowdeswell's Delphiniums for supplying this excellent information on growing successful delphiniums.


Wairere Nursery
826 Gordonton Road, R D 1, Hamilton 3281 Ph: (07) 824 3430 Email: