Common Mistakes to Avoid When Planting Spring Bulbs
Spring bulbs give one of the best returns on effort in the garden. You spend an afternoon on your knees in October and, come March, you have colour when almost nothing else is doing anything at all. The catch is that bulbs are quietly unforgiving. Planted badly, they don't sulk politely — they rot, come up blind, or push out a single sad leaf and stop there. Most failures aren't bad luck. They are one of a handful of familiar mistakes, and every one of them is easy to correct.
Whether you are filling a border, layering a container or naturalising a patch of rough grass, the same rules apply. Get these right and the bulbs will do the rest, year after year.
Planting too shallowly
This is the error I see most often, usually from people who dig a hole with a trowel, drop the bulb in and hope for the best. A bulb sitting too near the surface gets no protection from hard frost, dries out fast in a mild spring, and is often shoved up out of the ground by its own roots. By February you have a row of small onions sitting on top of the soil.
The standard guide is to plant at two to three times the bulb's own height. Measure the bulb from base to tip, then add that depth again twice below its base. A 5cm daffodil bulb goes into a hole roughly 15cm deep — that's measured from the base of the bulb, not the top. Crocus, snowdrops and other small bulbs are happy at about 8–10cm. Big alliums and large narcissi want 15–20cm, sometimes more in sandy soil.
If you have already planted too shallow, don't panic. Wait until the leaves have yellowed and died back in early summer, lift the bulbs, and replant them deeper. Shuffling them about while they are still in growth does far more harm than leaving them for a few months.
Burying them too deep — or upside down
Too deep is less common but perfectly possible, particularly in heavy clay where a generous hole is easy to dig and hard to fill sensibly. Bulbs planted far too deep burn through their stored energy pushing a shoot upwards, and small ones may never reach the surface at all. Large bulbs are reasonably tolerant; small ones are not.
Check the orientation while you're at it. Pointy end up, flat base — where the roots emerge — down. If you genuinely cannot tell, which happens with round little bulbs, plant it on its side. The shoot will sort itself out and grow upwards regardless.
Choosing a spot that stays wet
Bulbs rot in waterlogged ground, and in a British winter that accounts for a great many empty gaps in spring borders. They need soil that drains freely: a sunny border, a raised bed, the base of a south-facing wall, or a container with plenty of grit and crocks in the bottom.
Signs a spot is a bad bet
- Water still standing a full day after heavy rain
- A hollow at the bottom of a slope where the soil stays dark and sticky
- Heavy clay that clumps and gleams when you turn it over
- Beneath dense evergreen cover, where rain rarely reaches and the soil stays cold and damp
If you have no alternative, improve the ground before planting. Fork well-rotted compost or horticultural grit into the planting area to roughly the depth of your hole, and plant slightly shallower than the rule suggests — around one and a half times the bulb height — so water drains past the bulb rather than sitting around it. Growing them in pots is often the simpler answer for damp corners.
Buying bulbs that were never going to perform
Firm, heavy bulbs with their papery skins intact are what you want. Soft, squashy, mouldy or sprouting ones will struggle, and bargain mixed bags frequently contain undersized bulbs that flower poorly in their first year, if at all. Buy loose bulbs from a garden centre or a reputable supplier where you can pick them up and feel them.
Then plant them promptly. Bulbs left in a warm, dry room for weeks shrivel quietly and lose the reserves they need for flowering. If you can't plant immediately, keep them cool, dark and ventilated — a shed or garage is ideal — and get them in within a week or two.
Planting them one by one, in tidy rows
A single bulb dotted here and there around a border looks like an accident rather than a design. Spring bulbs work best in drifts or generous clumps, where the colour reads as a deliberate sweep.
An easy trick: take a handful of bulbs, toss them gently onto the soil, and plant each one where it lands. The result looks natural because it is random. As a rough guide, space small bulbs about 5–8cm apart and large daffodils and tulips 10–15cm apart. Don't be timid about numbers — bulbs multiply over time, and a thin first year is disappointing to look at.
For containers, you can layer bulbs at different depths to extend the display: tall daffodils at the bottom, tulips in the middle, crocus or grape hyacinths near the top. Just keep the deepest ones a decent distance above the drainage layer.
Cutting the leaves back too soon
It is tempting to tidy up the moment the flowers fade, but those straggly leaves are the bulb's solar panels. They are busy converting sunlight into the food store that will fuel next spring's flowers. Cut them off early and you get leaves the following year and no blooms.
Leave the foliage for at least six weeks after flowering, until it has gone yellow and started to flop. Deadhead the flowers as they fade so the plant doesn't waste energy on seed, but keep every leaf. If the collapsing foliage bothers you, plant bulbs behind later-flowering perennials that will grow up and hide the mess.
A quick checklist before you dig
- Choose a spot that drains freely and gets sun for at least part of the day.
- Check each bulb is firm and the papery skin is intact.
- Work out your depth: two to three times the bulb's height.
- Plant pointy end up, flat base down, with a little grit beneath if your soil is heavy.
- Plant in clumps rather than single file.
- Water once after planting, then leave them to the weather.
- Mark the spot so you don't dig them up by mistake.
- After flowering, deadhead and leave the leaves for six weeks.
Get those basics right and spring bulbs become the least demanding part of the garden — planted once, enjoyed for years, and quietly multiplying while you get on with something else.
Photo: katerinavulcova / Pixabay