Planting instructions

Professional Facts & Tips

  • Unpack the flower bulbs straight away on arrival and check the quality.
  • Keep the bulbs in a cool (no warmer than 17°C), dry and dark place and ensure adequate ventilation until the time of planting.
  • Plant your flower bulbs and tubers as soon as possible after delivery.
  • Plant summer flowering bulbs and tubers AFTER the last frost date in your area.
  • Quality bulbs and well drained soil are the two most important ingredients to successful flowering bulbs, tubers, corms and perennials.
  • Summer bulbs require a great deal of water immediately after planting. The soil in your garden should be continually moist.
  • Sprouting is healthy; plants are anxious to get into the ground again.
  • Maintain a pH level of 6 to 7 to bring out the true color of flower bulbs.
  • Additional fertilizer is not necessary for flower bulbs and tubers.
  • Many flower bulbs and tubers are well suited for patio containers and should be planted closer for a full look.
  • A variety of flower bulbs make great cut flowers. Some of the taller varieties may require staking.
  • You may need to lift your summer flowering bulbs and tubers in the Fall and replant next Spring. Shake off any soil and air dry for several days before storing in a cool, dry, well ventilated location. Do not store in plastic; plants need to breathe.

Plant the bulbs at the right time

  • Spring flowers
    For example Tulips, Narcissi and Daffoldils, Hyacinths, Muscari, Cocuses and many more.
    These bulbs need a cold period to be able to flower: they can be planted from September to December (depending on temperature). 
  • Summer flowers
    For exmaple Dahlias, Gladioli, Lilies, Anemones, Calla lilies, Begonias, Perennials and many more.
    These bulbs are usually planted in April or May. Important is that the bulbs will be planted after the last frost date in your area. The ideal soil temperature for summer flowering bulbs, tubers, cormn and plants is approx 13 degrees.

Flower bulbs planting depth and spacing

There is a mnemonic bridge to remember how deep and how far apart your flower bulbs plant. For the planting distance keep 3x the width of the bulb and keep 3x the height of the bulb before planting. A tulip of 5 centimeters must therefore be planted 15 centimeters deep and 15 cm apart.
Exceptions are begonias and dahlias, which have to be planted just under the surface.

Planting schedule


Cultivar Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Spacing (cm) Depth (cm) Full sun, Dappled shade, Shade
Agapanthus               20 10 F
Allium           25 15 F, D
      30 3 F, D, S *
Anemone       5 5 F, D
Begonia           15 3 F, D *
Canna               30 15 F
Chionodoxa               3 3 F, D, S
Convallaria majalis         3 5 S
Crocus - Autumn (Crocus Sativus)               3 6 F, D
Crocus - Spring             3 6 F, D
Cyclamen 5 3 D, S *
Dahlia           25 5 F, D
Eranthis hyemalis             5 5 F, D, S
Eremurus     40 10 F
Erythronium               5 5 D, S
Eucomis               15 5 F, D
Freesia           8 8 F, D
Fritillaria             30 20 F, D, S
Galanthus                 7 10 F, D, S
Gladioli             10 10 F
Hyacinthoides             4 6 F, D, S
            15 15 F, D
Iris             10 6 F, D
Ixia             30 7 F
Leucojum aestivum             12 12 F, D
Lilium ↧  ↧  20 14 F, D, S
Muscari           5 3 F, D, S
Narcissus           7 15 F, D
Ornithogalum     10 8 F, D
Oxalis                 5 5 F,D
Ranunculus               20 5 F, D
Scilla                 3 5 F, D
Sparaxis     10 8 F
Tigridia                 10 8 F, D
Tulipa           10 15 F, D, S

* Usually cultivated indoors

How many bulbs do you need per m2

It is always good to know how many flower bulbs you can plant at a specific area. Planting too close can sometimes increases the risk of diseases, while too few plants can give a disappointing result. We also take into account that the bulbs are combined with other (fixed) plants.

Combination planting

  Allium (small species) 20-30            Galanthus 50         
  Allium (tall species) 5-10   Hyacinthoides 15-20
  Anemone blanda 30-35   Hyacinthus 15
  Anemone coronaria 20   Ipheion 20-30
  Camassia 7-10    Iris reticulata 15-20
  Chionodoxa (small) 40   Leucojum aestivum 15
  Chionodoxa (tall) 15-20   Leucojum vernum 25
  Colchicum 20   Muscari 20-25
  Convallaria majalis 40   Narcissus 15-20
  Corydalis 25-30   Nectaroscordum 5-7
  Crocus 50   Ornithogalum nutans 15
  Eranthis 50   Ornithogalum umbellatum 15-20
  Eremurus bungei 1-3   Puschkinia 30-35
  Erythronium 10-15   Scilla 30-35
  Fritillaria (small) 10   Tulipa (small) 20-25
  Fritillaria (tall) 5-7   Tulipa (tall) 15

Bulk planting

  Allium (small species) 100            Galanthus 150      
  Allium (tall species) 15-20   Hyacinthoides 40
  Anemone blanda 75   Hyacinthus 25
  Anemone coronaria 100   Ipheion 80
  Camassia 10-20    Iris reticulata 50
  Chionodoxa (small) 75   Leucojum aestivum 30
  Chionodoxa (tall) 50   Leucojum vernum 50
  Colchicum 20   Muscari 100-150
  Convallaria majalis 75   Narcissus 25-50
  Corydalis 100   Nectaroscordum 20-25
  Crocus 50-75   Ornithogalum nutans 75-100
  Eranthis 50   Ornithogalum umbellatum 75-100
  Eremurus bungei 5   Puschkinia 100
  Erythronium 50-60   Scilla 100
  Fritillaria (small) 100   Tulipa (small) 80
  Fritillaria (tall) 10   Tulipa (tall) 60

Mechanical planting

Our special planting machine makes it possible to plant large quantities of bulbs under grass, for example in verges along roads, in lawns and on roundabouts. Mechanical planting means you can reduce the cost of labour significantly.
Rent or buy a planting machine at Green Graden flowerbulbs.

More information about mechanical planting..


Planting under grass
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