Naturalising

These are fleshy, rounded, underground storage organs, usually sold and planted while dormant. Examples include daffodils, tulips, hyacinths, lilies, onions and garlic. The term is often used to cover other underground storage organs, including corms, tubers and rhizomes.

Naturalised bulbs can also give interest to areas of the garden that otherwise might not bloom. Under deciduous trees, where the conditions are too dry and shady for most plants, you can use spring- or autumn-flowering bulbs because they are in growth when the trees have few leaves to cast shade. Suitable choices include anemones, crocuses, scillas and hardy cyclamen, such as C. hederifolium and C. coum.

Bulbs for naturalising in grass

Crocus (Spring Flowering)

• Crocus biflorus ‘Blue Pearl’ AGM
• C. chrysanthus ‘Cream Beauty’ AGM and 'Gipsy Girl’
• C. etruscus 'Zwanenburg' AGM
• C. flavus subsp. flavus AGM
• C. sieberi subsp. sublimis 'Tricolor' AGM
• C. sieberi subsp. atticus 'Firefly'
• C. tommasinianus AGM and cultivars ‘Ruby Giant’ and ‘Whitewell Purple’

Crocus (Autumn Flowering)

• Crocus banaticus
• C. nudiflorus
• C. pulchellus
• C. speciosus AGM and forms ‘Albus’ AGM, ‘Artabir’, ‘Conqueror’, ‘Oxonian’

Narcissus for Short Grass

• Narcissus assoanus
• N. bulbocodium AGM  (short grass moist soil)
• N. cyclamineus AGM and hybrids, ‘February Gold’ AGM, ‘Peeping Tom’ AGM, ‘Tête-à-Tête’ AGM
• N. ‘Hawera’ AGM
• N. ‘Jack Snipe’ AGM
• N. ‘Minnow’ AGM
• N. obvallaris (Tenby daffodil) AGM
• N. pseudonarcissus and variants
• N. ‘W P Milner’

Narcissus for Taller Grass

• Narcissus poeticus ‘Plenus’ and N. poeticus var. recurvus AGM

Most of the larger trumpet and large cupped daffodil hybrids will naturalise well.

Established cultivars suitable for taller grass include:

• N. ‘Actaea’ AGM
• N. ‘Carlton’ AGM
• N. ‘Ice Follies’ AGM,
• N. ‘Mount Hood’ AGM

Other Bulbs

• Allium hollandicum AGM, A. karataviense AGM, A. moly AGM, A. stipitatum, A. triquetrum, A. ursinum
• Anemone apennina AGM, A. blanda AGM, A. nemorosa AGM
• Camassia leichtlinii subsp. suksdorfii Caerulea Group
• Chionodoxa forbesii
• Colchicum autumnale, C. speciosum AGM
• Cyclamen hederifolium AGM, C. coum AGM
• Eranthis hyemalis AGM (short grass)
• Erythronium dens-canis AGM (short grass)
• Fritillaria meleagris AGM (moist soils)
• Galanthus elwesii AGM, G. nivalis AGM
• Gladiolus communis subsp. byzantinus AGM
• Hyacinthoides non-scripta (British bluebell)
• Iris reticulata ‘George’ AGM
• Leucojum aestivum, L. vernum AGM
• Muscari armeniacum AGM, M. neglectum
• Nectaroscordum siculum
• Ornithogalum nutans AGM, O. umbellatum
• Scilla sibirica AGM, Scilla bifolia AGM
• Tulipa spengeri AGM, T. sylvestris

Spring-flowering bulbs should be planted in autumn. This will ensure that, if you are planting into turf, it quickly re-roots rather than dying back in dry or frosty weather. 

Summer-flowering bulbs can be planted in autumn if they are hardy (Camassia, for example), or in spring if they are more tender, such as Gladiolus communis subsp. byzantinus.

This method works equally well in borders as in lawns and wildflower areas:

1. When planting bulbs for naturalising, scatter them randomly over the chosen area and plant them where they fall. As these bulbs will be in place for several years, check that the bulbs are not very close to each other as overcrowding will reduce flowering.
2. Dig planting holes with a trowel or, in grassed areas, use a bulb planter. The holes need to be about three times the depth of the bulb, as shallow planting tends to weaken the bulbs because they are more prone to drying out.
3. Break up some of the soil from the plug of turf removed with the bulb planter, and use this to backfill around the bulb once it is in the hole. 
4. Replace the turf on the top of the hole. Aim to make the top of the turf plug level with the surrounding lawn surface.

Alternative method

When planting small bulbs, such as crocuses, in areas of grass, lift or roll back sections of turf. Fork over the soil and add a little balanced fertiliser, such as Growmore. If possible, score the underside of the turf with a hand fork to loosen the soil before replacing it. Firm the turf by hand or by gently tamping with the back of a rake.

There aren’t many problems to watch out for, apart from checking that the bulbs are healthy to start with (discarding any that are soft or show signs of rot).

However, the following can be troublesome at times: slugs, snails, squirrels (particularly with tulips and crocus), daffodil viruses, tulip viruses, snowdrop grey mould and narcissus basal rot.