How to grow Delphiniums in the UK
Tall spires of true blue flowers - the queen of the summer border.
- DifficultyA bit more care
- WhereBeds or Pots
- Sunfull sun
- Grows to150cm
- Spacing60cm
- Time to first pickabout 10 weeks
- Typeperennial
When to sow, plant and harvest delphiniums
| Plant | early April to late May |
|---|---|
| In flower | early June to late July |
Dates are for central England. Sow about two weeks later in the north and Scotland, and up to two weeks earlier in the south and south west. Get the dates for your postcode.
Planting it
- Water your new plants in their pots first
- Dig a hole a bit bigger than the pot
- Tip the plant out gently, holding the leaves, not the stem
- Pop it in the hole, firm the soil around it, and water well
- Space the plants about 60cm apart each way
Top tips for growing delphiniums
- Slugs adore the spring shoots - protect them.
- Stake them early before they get tall.
Looking after delphiniums
- Week 2: Stake your delphiniums before they get tall and floppy
Soil and feeding
Poor soil - really!. Nasturtiums flower best in poor soil. Feed them and you get all leaves and no flowers.
Pests and problems
- Slugs & snails: munch seedlings overnight, worst in wet weather
- Slugs adore the new shoots - go on slug hunts in spring
Harvesting and eating delphiniums
Cut back after flowering for a second flush in autumn.
Saving your own delphiniums seed
Late summer and autumn, as the flowers fade.
- Stop deadheading a few flowers - let them fade on the plant
- When the seed heads are dry and brown (and the seeds rattle), snip them off on a dry day
- Shake the seeds into a paper bag
- Spread on a plate to dry for a week
Where to buy delphiniums plants
Thompson & Morgan · Suttons · Amazon
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Delphiniums questions
When do I plant out delphiniums?
Plant delphiniums out from early April to late May.
When can I enjoy delphiniums?
Delphiniums is ready from early June to late July. Cut back after flowering for a second flush in autumn.
How long do delphiniums take to grow?
Roughly 10 weeks from sowing or planting until the first harvest.
Are delphiniums easy to grow?
Delphiniums are rated 'a bit more care' for beginners, and can be grown in the ground or a raised bed or in pots and containers.
Plan your own garden: it tells you what to do and when, for your postcode.
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