Laidback Gardener Tip of the Day

Peat Pots for Fragile Roots

20150308AIn this season where so many gardeners are starting their flowers and vegetables indoors, here are some thoughts on peat pots commonly used as containers for seedlings.

Several seedlings (zinnias, melons, castor beans, etc.) have fragile roots and can suffer during transplanting if you sow them in plastic pots or cell packs because this exposes their root ball to damage as you try to replant them. This is where peat pots come in.

20150308BThese round or rectangular pots are made of pressed peat with a bit of added wood fiber. They are strong enough to use as plant pots, but unlike plastic pots, they are porous, letting air and water circulate… and also allowing the roots of your seedlings to grow through them. You’ll actually see the roots penetrating the wall of the pot as they grow.

To use peat pots, simply fill them with your favorite seed-sowing mix and moisten well before sowing. Then sow the seeds, water and take good care of the seedlings until planting time. When that time does come, all you have to do is to plunk the pot into a planting hole, without removing the pot, and cover with soil. Water well… and your seedlings will continue to grow without slowing down, as they were never subjected to transplant shock. Not only will the roots grow right through the walls to establish themselves in the surrounding soil, but the pot itself will decompose over time, leaving no trace in the soil.

Strange Advice

This is so simple you might wonder why I’ve even bothered to explain it. Well, that’s because there are always people who manage to get it all wrong and then proudly publish their errors on the Internet.

There is no logical reason to pull the bottom off a peat pot… yet this advice is widely shared on the Internet.

Here’s one bit of dumb advice you’ll read on the Web: “you have to tear the bottom off the peat pot before planting so the roots can grow down into the soil”. Wait a minute! The roots are already growing through the bottom of the pot. If you remove it, you’ll damage them… and didn’t we just say peat pots are designed specifically for plants that have fragile roots? Just plant the whole pot: there is no need to tear anything off!

Worse yet, some people suggest peeling the entire peat pot off. Yet more nonsense! If you intend to remove a pot at planting time, why use peat pots at all? Plastic pots and cell packs are easier to remove and can be reused year after year, so are therefore cheaper. Use them if your eventual goal is to remove the pot.

Correct Advice

There is something you might want to tear off a peat pot, though.  When you transplant the seedlings in peat pots, you have to be careful to bury the entire pot. If the top edge sticks out of the ground, it will act as a wick and dry out the root ball. So if any of the pot does show, yes, you can tear that part off.

For Use Only on Fragile Seedlings

Let me repeat something before closing: peat pots are an added expense to growing plants from seed and one of the main reasons gardeners sow seeds is to save money. Peat pots offer no benefit whatsoever to the majority of seedlings compared to plastic pots or cell packs. It is simply wasteful to sow tomatoes, petunias, marigolds, and most other garden plants in peat pots. Reuse and recycle other containers for their care. Keep peat pots for those seeds whose fragile roots would otherwise make transplanting difficult.

Seeds That Need Peat Pots

The following plants all have roots that are either very fragile and therefore absolutely need to be sown in peat pots or fragile enough that they will be set back considerably if the root ball is mishandled when transplanting.

  1. Amaranth or love-lies-bleeding (Amarantbus spp.)
  2. Amsonia or bluestar (Amsonia spp.)
  3. Anise (Pimpinella anisum)
  4. Annual phlox (Phlox drummondii)
  5. Bachelor’s buttons (Centaurea cyanus)
  6. Baptisia or false indigo (Baptisia spp.)
  7. Bean, Hyacinth (Lablab purpureus, syn. Dolichos lablab)
  8. Bedding lobelia (Lobelia erinus)
  9. Beet or beetroot (Beta vulgaris Condivita group)
  10. Bells of Ireland (Moluccella laevis)
  11. Black-Eyed Susan Vine (Thunbergia alata)
  12. Blue lace flower (Trachymene coerulea, syn. Didiscus coerulea)
  13. Burning Bush (Bassia scoparia, syn. Kochia scoparia)
  14. Cabbage (Brassica oleracea)
  15. California poppy (Eschscholzia californica)
  16. Candytuft, Annual (Iberis amara)
  17. Carrot (Daucus carota)
  18. Castor oil plant (Ricinus communis)
  19. Celosia or cockscomb (Celosia spp.)
  20. Chervil (Anthriscus cerefolium)
  21. China aster (Callistephus chinensis)
  22. Clarkia (Clarkia unguiculata, syn. C. elegans)
  23. Climbing snapdragon (Asarina, Lophospermum and Maurandya)
  24. Cucumber (Cucumis sativus)
  25. Cup & saucer vine (Cobaea scandens)
  26. Cypress vine (Ipomoea quamoclit and others)
  27. Dill (Anethum graveolens)
  28. Dwarf morning glory (Convolvulus tricolor)
  29. Eggplant or aubergine (Solanum melongena)
  30. Everlasting (Xerochrysum bracteatum, syn. Helichrysum bracteatum)
  31. Fennel (Foeniculum vulgare)
  32. Flax (Linum spp.)
  33. Four O’Clock (Mirabilis jalapa)
  34. Gerbera (Gerbera spp.)
  35. Globeflower (Gomphrena globosa)
  36. Heuchera (Heuchera spp.)
  37. Hollyhock (Alcea spp.)
  38. Job’s tears (Coix lacryma-jobi)
  39. Kniphofia, torch lily or tritome (Kniphofia spp.)
  40. Larkspur (Consolida spp.)
  41. Lavatera or tree mallow (Lavatera spp.)
  42. Lisianthus (Eustoma grandiflora)
  43. Lovage (Levisticum officinale)
  44. Love-in-a-mist (Nigella damascena)
  45. Lupin (Lupinus spp.)
  46. Malope or mallow-wort (Malope trifida)
  47. Melon (Cucumis spp.)
  48. Mexican poppy (Argemone spp.)
  49. Mignonette (Reseda odorata)
  50. Milkweed (Asclepias spp.)
  51. Moonflower (Ipomoea alba)
  52. Morning glory (Ipomoea spp.)
  53. Nasturtium (Tropaeolum spp.)
  54. Nemophila or baby blue eyes (Nemophila spp.)
  55. Nolana (Nolana paradoxa and N. humifusa)
  56. Painted tongue (Salpiglossis sinuata)
  57. Peanut (Arachis hypogaea)
  58. Pepper (Capsicum annuum)
  59. Perennial pea (Lathyrus latifolius)
  60. Perilla (Perilla frutescens)
  61. Persil (Petroselinum crispum)
  62. Poppy, annual species (Papaver spp.)
  63. Portulaca or moss rose (Portulaca spp.)
  64. Pumpkin (Cucurbita pepo)
  65. Quaking grass (Briza maxima)
  66. Rodgersia (Rodgersia spp.)
  67. Squash (Cucurbita spp.)
  68. Statice (Limonium sinuatum)
  69. Summer savory (Satureja hortensis)
  70. Sunflower (Helianthus annuus)
  71. Sweet pea (Lathyrus odoratus)
  72. Toad lily (Tricyrtis spp.)
  73. Tulip poppy (Hunnemannia fumariifolia)
  74. Watermelon (Citrullus lanatus)
  75. Zinnia (Zinnia spp.)
  76. Zucchini or courgette (Cucurbita pepo)

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, will continue its mission of demystifying gardening and making it more accessible to all.

2 comments on “Peat Pots for Fragile Roots

  1. Pingback: What are biodegradable plant pots? – Trackanya

  2. Pingback: Sweet Pepper or Chili Pepper? Different Taste, Same Plant – Laidback Gardener

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