Top 20 tips for planting bulbs

Tulips in full bloom at the Keukenhof, the world's largest flower and tulip garden park in the Netherlands - Getty Images Europe
Tulips in full bloom at the Keukenhof, the world's largest flower and tulip garden park in the Netherlands - Getty Images Europe

There is little more visually appealing than a garden colour-bursting with bulbs in full bloom.

Thankfully, they're also relatively straightforward to plant. The general rule of thumb is to plant deep (deeper than you think), drain well (this is especially important for tulips, alliums and Iris reticulata), and sunbathe (especially while dormant).

Of course, each bulb will have its own rules and requirements to bloom best and a bit of pre-planting research will never go amiss. With this in mind, here is Josh Hoyland's top tips for planting bulbs, with virtually every trick in the book:

1. Prepare well

Remove weeds and incorporate lots of compost or other organic matter when planting bulbs. On heavy soils, dig in horticultural grit. Bulbs grown in pots need good drainage so put plenty of crocks in the bottom and use a well-drained compost. For my pots I use two parts John Innes No 2 with one part horticultural grit. Specialised bulb composts are expensive and only necessary in pots with poor drainage.

2. Time it right

Garden centres sell bulbs for autumn planting from the end of July and want them out of the way by September to make room for Christmas-tree baubles. August is far too early to plant spring-flowering bulbs. October is the best time for daffodils; November for tulips.

Plant daffodil bulbs in October  - Credit: Rex
Plant daffodil bulbs in October Credit: Rex

3. Big, fat and firm

When buying bulbs, reject any that are soft or showing signs of mould. Small bulbs may not flower in their first year.

4. Dig deep

Bulbs should be planted in holes three to four times as deep as the bulb itself. So, for example, a 1in crocus bulb needs to be planted in a hole 3-4in deep.

5. Fritillary finesse

Clumps of Fritillaria imperialis or F. persica look magnificent but can be difficult to achieve: on heavy soils the bulbs often rot during their first year. Placing the bulbs in the ground on their side will prevent water entering at the top and reduce the likelihood of them rotting.

6. Which way up?

If you are not sure, plant the bulb on its side: its stem will find its own way up.

7. Force later

The traditional time to start forcing hyacinths into flower is the third week of September, so they flower in time for Christmas. But there is always a surfeit of goodies at Christmas, so consider forcing bulbs for the lean weeks of January and February instead. Hyacinths will flower 10-12 weeks from potting if kept in a cool, dark room (or under a cardboard box) until they have shoots about 2in tall. 'Paper White' narcissi flower 8-10 weeks from potting and don't need to be kept in the dark.

Hyacinths are best forced to flower in September - Credit:  Martin Pope
Hyacinths are best forced to flower in September Credit: Martin Pope

8. Bulbs for shade

Not all bulbs need full sun. As well as woodland bulbs such as the dog's tooth violet (Erythronium dens-canis), and the wood anemone (Anemone nemorosa), many Mediterranean bulbs grow well in shade. Scilla peruviana has blue flowers the size of tennis balls and soon forms large colonies in cool, shady situations. Its relatives, the squills - Scilla siberica and S. bifolia - are aggressive plants that seed themselves everywhere, but the pools of blue they form are irresistible on dull spring days. The star-shaped flowers of Ipheion uniflorum create a similar effect but are less invasive.

If you have rich soil with plenty of added leafmould you will be able to grow the sumptuous black flowers of Fritillaria camschatcensis. The most majestic bulb for the dappled shade provided by deciduous trees is F. imperialis. A friend has masses of the deep orange form growing against a red-brick wall underneath a fig tree. It's a glorious sight.

9. Plot with pots

Fill large plastic pots with your favourite bulbs and, just before they are about to flower, use them to plug holes in the border. Plastic pots can also be slipped inside more elegant terracotta ones and whipped out when the bulbs are over. Store the pots behind a shed to allow the foliage to die down, keep them weed-free, top-dress with a layer of compost in the autumn, and bring them out again the following year.

10. Mark the spot

Plant labels can look ugly but are indispensable for marking the position of bulbs whose foliage has died back. A discreet wooden label will prevent the frustration caused by plunging a fork into a border and spearing a clump of your favourite alliums.

11. Hedge dwellers

The dry conditions at the base of hedges make ideal growing conditions for many bulbs. Tulips, and particularly species tulips, will be very happy on the south-facing side of a hedge, and can be left undisturbed for years. A few bulbs of Tulip whittallii planted at the base of my beech hedge have now formed large colonies. The bronze-orange flowers coincide with the first acid-green shoots of the beech.

On the shady side of the hedge, encourage carpets of Anemone blanda or the mauve and lavender flowers of Chionodoxa forbesii, a prolific self-seeder.

12. Damp lovers

Most bulbs need a period of dry conditions, but some only thrive in moist soils. In the wild, camassias grow in rich, moist meadows and need similar conditions in the garden. Leucojums also flower better in moist soils. The snakeshead fritillary, F. meleagris, only flourishes when grown in a damp soil.

Snakeshead fritillary only flourishes in damp soil  - Credit: Tony Buckingham
Snakeshead fritillary only flourishes in damp soil Credit: Tony Buckingham

13. Singular beauty

Eighteenth-century gardeners planted tulips individually, the better to appreciate their beauty. Bulbs planted singly in small terracotta pots and placed in an ordered manner around the garden bring instant elegance and formality. Use lily-flowered tulips, Fritillaria persica or large-flowered alliums.

14. Enemy tactics

The biggest destroyer of bulbs, particularly in urban gardens, is the squirrel. Although they dig up daffodils they don't eat them. But they have a voracious appetite for crocus and tulips. Planting the bulbs deeper than normal can help. Bulbs are most vulnerable after planting, when the soil is easy for squirrels to dig. Chicken-wire placed over the pot, or the freshly dug soil, will deter them.

15. Lawn games

It's not just crocus that will grow in lawns and short grass. Many miniature irises, particularly Iris histrioides, will be perfectly happy in a lawn that does not become waterlogged. Of the dwarf narcissi, it is the cyclamineus hybrids that are the best adapted to the conditions. Narcissus cyclamineus 'Jenny', which has creamy white flowers, spreads well in lawns. To plant, remove the turf with a spade, place the bulbs underneath and replace the turf. Don't cut the lawn until the bulbs' foliage has died down.

16. Long grass

Bulbs can also be grown in long, rough grass if you choose tall varieties that can compete. Fritillaria pyrenaica grows to about 18in tall and is easy and vigorous, even in grass. Narcissi are well-adapted to growing in grass, particularly the pheasant's eye narcissus, N. poeticus var. recurvus, and the old-fashioned N. 'W. P. Milner'. To plant the bulbs, remove clumps of grass with a bulb planter or with a mattock.

17. Viola partners

Wallflowers or forget-me-nots are the traditional partners for tulips. In pots and window boxes use violas instead - they will start flowering long before the tulips and provide a wide range of colour combinations. The Sorbet series is robust and floriferous.

18. More please

For sheer flower-power, bulbs are the cheapest plants available, so don't stint on the quantities you plant. Even in small gardens, massed plantings of a limited number of varieties is always most effective. In pots, allow for a dozen tulips per 12in container.

19. Lift and repeat

Left in the ground, tulips degenerate each year until they die; lifted, stored and replanted the following November they re-flower well. After flowering, remove the seed head and wait for the foliage to yellow and die back, then lift the bulbs, clean off any soil and store in boxes or net bags in a cool, dry place.

20. Limit your layers

Plant pots and windowboxes with no more than two layers of bulbs to prevent the unsightly spectacle of later-flowering plants appearing through the dying foliage of earlier ones.