20180326A 588ku.com.jpg
No need to dig down to China when sowing very fine seeds: just sow them on the surface of the mix. Source: 588ku.com

With seed-starting season in full swing, it’s worth pointing out that most seed packs indicate how deep you should sow the seeds they contain and how far apart you should space them. If they don’t, you will probably find this detail in a book or on the Internet.

If not, use the following rule which has served gardeners for generations: sow at a depth equal to 3 to 4 times the diameter of the seed and leave 1/2 inch (1.25 cm) between each seed (1 inch/2.5 cm in the case of larger seeds).

Fine Seeds: The Exception to the Rule

There is, however, one group of seeds you should not cover at all: very small seeds, those that are almost as fine as dust. Their small size indicates that, in nature as in the garden and in containers, they prefer to germinate on the surface of the soil. Moreover, these same seeds usually need light to germinate, so when you start them indoors, always place their pots in a brightly lit location, even before they show any green growth.

Here’s how to sow fine seeds:

20180326F Claire Tourigny, HC.jpg
Illustrations: Claire Tourigny, from the book Les idées du jardinier paresseux: Semis

1. Fill the container, whether a pot or a tray, with pre-moistened seed-sowing mix, evening out carefully.

20180326B Claire Tourigny, HC.jpg2. Sprinkle the seeds on the surface of the seedling mix.

20180326C Claire Tourigny, HC.jpg3. Gently press the soil with a block of wood or plastic so the seeds adhere to the mix, but aren’t covered.

20180326D Claire Tourigny, HC.jpg4. Lightly spray with warm water: this sends a message to them that it is time to germinate.

20180326E gardening.stackexchange.com.jpg
Cover the container with a clear dome and place in a brightly lit, warm spot to stimulate germination. Source: gardening.stackexchange.com

Afterwards, treat the containers like those of any other seeds: cover them with a clear plastic cover of some sort (mini-greenhouse) and place in a warm spot in bright light until germination occurs, avoiding full sun at first. After germination, remove the cover and start treating them like the seedlings they now are, watering regularly and giving them as much light or sun as possible.

Seeds It’s Best Not to Cover

Here is a partial list of seeds that you should not cover with sowing mix:

  1. Agastache (Agastache foeniculum and others)
  2. Ageratum (Ageratum houstonianum)
  3. Amsonia (Amsonia spp.)
  4. Angelica (Angelica archangelica and others)
  5. Angelonia (Angelonia angustifolia)
  6. Annual gypsophila (Gypsophila muralis)
  7. Astilbe (Astibe spp.)
  8. Aubrieta (Aubrieta spp.)
  9. Balloon Flower (Platycodon grandiflorum)
  10. Basil (Ocimum basilicum)
  11. Basket of Gold (Aurinia saxatilis, syn. Alyssum saxatile)
  12. Begonia (Begonia spp.)
  13. Bells of Ireland (Moluccella laevis)
  14. Bergenia (Bergenia cordifolia and others)
  15. Bleeding Heart (Dicentra spectabilis)
  16. Blue Fescue (Festuca ovina glauca and others)
  17. Blue Poppy (Meconopsis betonicifolia and others)
  18. Browallia (Browallia speciosa)
  19. Canterbury Bells (Campanula medium)
  20. Dusty Miller (Senecio cineraria, Centaurea cineraria and others)
  21. Clarkia (Clarkia unguiculata, syn. C. elegans)
  22. Climbing Snapdragon (Asarina, Lophospermum and Maurandya) Columbine (Aquilegia spp.)
  23. Corydalis (Corydalis spp.)
  24. Cosmidium (Cosmidium burridgeanum)
  25. Creeping Zinnia (Sanvitalia procumbens)
  26. Dame’s Rocket (Hesperis matronalis)
  27. Edging Lobelia (Lobelia erinus)
  28. English Daisy (Bellis perennis)
  29. Eucalyptus (Eucalyptus cinerea, E. globulus and others)
  30. Everlasting (Xerochrysum bracteatum, syn. Helichrysum bracteatum)
  31. Ferns (all species: Matteuccia, Athyrium, etc.)
  32. Flowering Tobacco (Nicotiana alata, N. sylvestris and others)
  33. Foamflower (Tiarella cordifolia)
  34. Forget-Me-Not (Myosotis sylvatica and others)
  35. Gaillardia (Gaillardia x grandiflora and others)
  36. Garden Mum (Chrysanthemum morifolium, syn. Dendranthema x grandiflorum)
  37. Goat’s Beard (Aruncus dioicus and others)
  38. Golden Marguerite (Anthemis tinctoria)
  39. Hardy Gloxinia (Incarvillea delavayi and others)
  40. Heuchera (Heuchera spp.)
  41. Himalayan Balsam (Impatiens glandulifera)
  42. Ice Plant (Dorotheanthus bellidiformis and Mesembryanthemum crystallinum)
  43. Kochia (Bassia scoparia, syn. Kochia scoparia)
  44. Laurentia (Laurentia axillaris, syn. Isotoma axillaris)
  45. Lemon Balm (Melissa officinalis)
  46. Leopard’s Bane (Doronicum spp.)
  47. Liatris (Liatris spicata and others)
  48. Lungwort (Pulmonaria saccharata and others)
  49. Masterwort (Astrantia major and others)
  50. Meadow-Rue (Thalictrum spp.)
  51. Mealy Sage (Salvia farinacea)
  52. Mexican Sunflower (Tithonia rotundifolia)
  53. Mignonette (Reseda odorata)
  54. Mimulus (Mimulus spp.)
  55. Monk’s Hood (Aconitum spp.)
  56. Mountain Sandwort (Arenaria montana)
  57. Nemesia (Nemesia strumosa and others)
  58. Oregano (Origanum vulgare)
  59. Oriental Poppy (Papaver orientale, P. bracteatum and others)
  60. Osteospermum (Osteospermum spp., syn. Dimorphotheca spp.)
  61. Ox-Eye (Buphthalmum salicifolium)
  62. Pennisetum (Pennisetum villosum, P. setaceum)
  63. Perennial Candytuft (Iberis sempervirens and others)
  64. Perennial Lobelia or Cardinal Flower (Lobelia cardinalis, L. siphilitica and others)
  65. Rockcress (Arabis caucasica and others)
  66. Rodgersia (Rodgersia aesculifolia and others)
  67. Saxifrage (Saxifraga spp.)
  68. Scarlet Sage (Salvia splendens)
  69. Snapdragon (Antirrhinum majus)
  70. Spanish Poppy (Papaver rupifragum)
  71. Stock (Matthiola incana)
  72. Summer Savory (Satureja hortensis)
  73. Sweet Alyssum (Lobularia maritima)
  74. Tansy (Tanacetum vulgare)
  75. Throatwort (Trachelium caeruleum)
  76. Thyme (Thymus vulgaris and others)
  77. Virginia Stock (Malcomia maritima)
  78. Wishbone flower (Torenia fournieri and others)
  79. Yarrow (Achillea spp.)20180326A 588ku.com

1 comment on “Seeds You Don’t Need to Cover

  1. Pingback: Diy Seedling Protector

Leave a Reply

Sign up for the Laidback Gardener blog and receive articles in your inbox every morning!