How to grow Zinnias in the UK
Bright, bold flowers in every colour - butterflies love them.
- DifficultyA bit more care
- WhereBeds or Pots
- Sunfull sun
- Grows to60cm
- Spacing30cm
- Time to first pickabout 12 weeks
- Typeannual
When to sow, plant and harvest zinnias
| Sow indoors | early April to mid May |
|---|---|
| Plant out | early June to late June |
| In flower | mid July to early October |
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.
Starting it indoors
- Fill a small pot or tray with seed compost
- Push the seeds in (0.5cm deep) - a couple per pot
- Water gently, then put them on a bright windowsill
- Keep the compost damp but not soggy - check it every day
- When they have 2 proper leaves, give each seedling its own pot
Planting it out
- Toughen them up ('hardening off'): put them outside in the day for a week, bring them in at night
- 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 30cm apart each way
Top tips for growing zinnias
- They hate cold - don't plant them out until June.
Looking after zinnias
- Week 4: Snip off dead zinnia flowers so new ones keep coming
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
- Protect young plants from slugs
Harvesting and eating zinnias
Cut when the stem below the flower feels stiff (wiggle test).
Saving your own zinnias 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 zinnias seeds
Thompson & Morgan · Suttons · Amazon
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Zinnias questions
When should I sow zinnias in the UK?
In the UK, sow zinnias indoors from early April to mid May. These dates suit central England; sow about two weeks later in the north and Scotland and up to two weeks earlier in the mild south and south west.
When do I plant out zinnias?
Plant zinnias out from early June to late June, once the last frost has passed.
When can I enjoy zinnias?
Zinnias is ready from mid July to early October. Cut when the stem below the flower feels stiff (wiggle test).
How long do zinnias take to grow?
Roughly 12 weeks from sowing or planting until the first harvest.
Are zinnias easy to grow?
Zinnias 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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