Autumn is the best time to plant the bulbs that will carry your garden through to spring. It is also one of the easiest jobs to get quietly wrong. A daffodil set two inches too shallow will heave itself out of the ground in the first hard frost. A crocus bed left unprotected becomes a squirrel buffet. A tulip planted in soggy clay simply rots, leaving a gap where a flower should be next April. None of these are difficult problems to avoid. They just need a handful of decisions made before the trowel goes in.

Depth: the three-times rule, and why it matters

The old guideline still holds: plant a bulb so there is soil above it roughly three times the bulb's own height. Measure from the base of the bulb to the soil surface, not from the tip.

A 5cm daffodil bulb goes in about 15cm deep. Tulips want 15–20cm. Crocus and other small bulbs sit at 5–7cm.

What goes wrong when you ignore it:

• Too shallow. Frost lifts the bulbs, roots dry out during a mild spell, and tall stems flop. Shallow bulbs are also the first ones squirrels find.
• Too deep. Small bulbs use all their stored energy reaching the surface and either flower late or not at all, particularly in heavy soil.
• Wrong way up. Rarely fatal — a bulb planted pointy end down will usually right itself — but it costs energy. Nose up, roots down.

Loosen the soil beneath where the bulb will sit so the roots can move. In most soils, a small handful of grit in the base of the hole is worth the effort.

Drainage matters more than feeding

Bulbs are storage organs. Sit them in saturated soil through a British winter and they rot, sometimes turning to grey mush before Christmas. Heavy clay, a low corner of the garden, or a pot without drainage holes are the usual culprits.

• Plant on a slight ridge or mound so surplus water runs away.
• Fork grit or well-rotted compost through the whole planting area, not just the hole.
• Choose a raised bed or containers if the ground is permanently wet.
• If the spot puddles after rain, plant somewhere else. It will not improve by spring.

In pots, drainage holes do the real work. A layer of crocks in the bottom does very little for drainage; a free-draining compost mixed with grit or bark is a better use of your time. Don't tuck fertiliser directly beneath the bulb either, as it can scorch young roots. Mix it into the soil above, or top-dress in spring.

Timing: right bulb, right month

Bulbs planted too early in still-warm soil can start into growth and then be caught by cold. Planted too late, they don't have time to root before winter.

• Daffodils, crocus, snowdrops and hyacinths: September to early October.
• Alliums: October.
• Tulips: November. Later planting reduces the risk of tulip fire, a fungal problem that disfigures leaves and flowers.

Wait for cool, moist soil. Don't plant into frozen ground or a bone-dry bed — water the hole if the autumn has been dry.

Buying and storing bulbs

Choose bulbs that feel heavy and firm for their size, with their papery tunics intact. Skip anything soft, mouldy or shrivelled; it was never going to flower. Keep them cool, dark and airy until planting — a paper bag in the shed or garage, not a sealed plastic bag in a warm kitchen.

Squirrels, mice and the crocus heist

Nothing undoes an afternoon's planting faster than a squirrel. Crocus, tulips and small irises are favourites. Mice and voles work from below, while rabbits and deer graze the foliage later on.

No single trick works everywhere, so use a combination:

• Plant deeper than the minimum where you can.
• Firm the soil and top with grit or gravel rather than soft mulch.
• Lay chicken wire over the bed, pegged at the edges, and leave it until shoots push through.
• Use wire baskets for pots and small beds.
• Chilli powder or garlic sprays may help for a while, but need renewing after rain.

Daffodils, alliums, snowdrops and fritillaries are usually left alone. If wildlife is a persistent problem in your garden, lean on those.

Where bulbs go, and what happens afterwards

A row of single bulbs spaced evenly along a border always looks thin. Bulbs look best in drifts and clumps. Tip them out of the bag, arrange them on the soil before digging, then plant in groups of five, seven or nine. Odd numbers tend to read more naturally than even ones.

Most bulbs want sun, though snowdrops and cyclamen cope with shade under deciduous trees because they flower before the canopy closes over them.

After flowering, the leaves matter as much as the flowers did. They feed the bulb for next year. Leave them for at least six weeks after the last bloom, until they yellow and pull away easily. Don't cut them early and don't tie them into knots. Deadhead spent flowers to stop the plant putting energy into seed, but keep the stems. A high-potash feed while the leaves are still green helps next year's display. And label the spot: it is surprisingly easy to fork through dormant bulbs in summer.

A quick autumn checklist

1. Check drainage before you dig. Grit, raised beds or pots solve most problems.
2. Plant at three times the bulb's height.
3. Match the month to the bulb: daffodils in September, tulips in November.
4. Buy firm, heavy bulbs and store them cool and dry.
5. Plant in clumps rather than single file.
6. Protect with wire, grit, or both.
7. Leave the foliage for six weeks after flowering.
8. Label where everything went.

If this spring was disappointing, run through the same list in reverse. Blind bulbs usually point to shade, shallow planting or a dry summer. Missing bulbs mean wildlife. Yellowed, floppy leaves suggest poor drainage. Fix one thing this autumn and next spring will look better for it.

Photo: MabelAmber / Pixabay