Bulbs work on a simple principle: everything needed to flower is already packed inside the bulb. All you supply is a place and the time to root. That's precisely why they're planted in autumn — they need several weeks of cool, moist conditions to make roots, then a cold period that triggers flowering.
When to plant — and why tulips go in last
| Bulb | Planting window | Flowers |
|---|---|---|
| Daffodils | September – mid-October | March – April |
| Crocuses | September – October | February – March |
| Grape hyacinths | September – October | April |
| Snowdrops, snowflakes | September (they dry out fast) | February – March |
| Hyacinths | October | April |
| Tulips | October – November | April – May |
| Ornamental alliums | October | May – June |
Tulips are the one exception where it pays to wait. Planted into warm September soil they push up growth before winter and are more prone to the fungal disease tulip fire. Plant them once it has turned cold — November is fine, as long as the ground can still be dug.
Depth and spacing: the rule of three
The universal rule is: plant at three times the height of the bulb. So a large tulip (5 cm) goes 15 cm down, a crocus (2 cm) about 6 cm. Space bulbs roughly two bulb-widths apart.
Shallow planting is the commonest mistake: bulbs work their way up, freeze more easily, and tulips planted shallowly often last a single season. Planted deeper, tulips persist in the border for years and cope better with summer drying.
Where and how to plant
- Choose a spot that doesn't sit wet — bulbs rot in waterlogged ground. On heavy soil, drop a handful of sharp sand into the bottom of the hole.
- Plant nose up — obvious with tulips and daffodils; with irregular tubers such as anemones, shape won't help you, so plant them flat and let them sort themselves out.
- Plant in groups, not rows — 7, 9 or 11 bulbs in an irregular cluster reads as natural; a straight line reads as a military parade.
- Naturalise them in grass — throw a handful across the area and plant them where they land. Use crocuses or species daffodils, which cope with later mowing.
- Water them in — that first watering starts the rooting that has to happen before the ground freezes.
Guarding against rodents, and what to do after flowering
Tulips, crocuses and hyacinths are a delicacy for voles and mice. Daffodils and grape hyacinths, by contrast, are toxic and get left alone — which is why planting them together works: daffodils around tulips act as a natural barrier. Where rodent pressure is heavy, plant into wire baskets.
After flowering, remove the spent flower heads so the plant doesn't put energy into seed — but let the leaves die down completely. That's where next year's reserves are built. Mowing down green daffodil foliage in a lawn is the surest way to cancel next spring's display.
Frequently asked questions
What's the latest I can plant bulbs?
As long as the ground can be dug and isn't frozen — in mild winters that can mean December. Late planting means later, weaker flowering, but it still beats leaving bulbs in the bag, where they'll dry out or rot anyway.
Do I have to lift tulips every year?
Not if they're planted deep enough (15 cm) somewhere that dries out over summer. Large-flowered hybrid tulips will still weaken after two or three years. Species and Darwin hybrid tulips persist in a border for many years untouched.
Why didn't my bulbs flower?
Usually one of three reasons: they were planted too shallow, last year's foliage was removed or mown off too early, or rodents ate the bulbs. With tulips, add a fourth possibility — the bulb was exhausted after the previous season and split into several small ones that aren't yet strong enough to flower.