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Seeding and planting: when and how

Violet and pansy seedlings
Photo: Jardin botanique de Montréal (Lise Servant)
Viola seedlings

Indoor seeding should start as early as February for slow-developing plants such as geraniums, begonias or impatiens. As a general rule, vegetables and flowers should be sown from early March to late April. Sowing earlier is pointless because the plantlets easily etiolate and become too old to transplant. In addition, many plant varieties cannot be seeded indoors. Check the seeding calendars for vegetables and for annuals for more information.

If you live outside the greater Montréal region, you should delay planting outside.


  • Once you have filled your containers to one centimetre from the top, the surface should be levelled and lightly packed before sowing.
  • Seeds should be distributed evenly and sparingly. Planting seedlings too densely may cause young plants to etiolate and precipitate the need to transplant.
  • The smaller the seeds, the shallower they should be sown.
  • Simply sift a little of the seedling mix over the seeds.
  • Certain seeds, such as Begonia semperflorens need light in order to germinate and must not be covered.
  • Read the instructions on each seed packet or consult gardening books if you have any questions.
  • To avoid disturbing the seeds when watering, the base of the container should be placed in water for 15 minutes. Then cover the top with a glass plate or a plastic cover.
  • As soon as the plants sprout, remove the cover and lower the temperature by a few degrees.
  • Plants in the cucumber family (melon, squash, pumpkin, etc.) have very fragile roots and cannot be transplanted. They must be planted individually in biodegradable peat containers.
  • Certain species such as tomatoes and marigolds can also be sown directly in individual pots and need not be transplanted.


Transplanting young plants is necessary so that they have the space needed to grow properly. Transplanting causes secondary roots to develop, ensuring better support for the plant. The subsoil used for bedding must contain more nutritive matter to meet the plant's needs.

Young plants can be transplanted once they have two true leaves. If you wait any longer, the roots will become entangled and they will be more difficult to transplant without damage, thus affecting growth.

Young plants should be watered before transplanting. They should be lifted gently with a small stick. Separate each plant from the group by holding it by a leaf and not by the stem. Transplant it into a small case or individual pot by covering it up to the bottom leaves, and water gently. After two weeks, fertilize the plant with a soluble fertilizer dissolved in water. An algae- or fish-based biological fertilizer is preferable.

Garden planting

Moving young plants from the house to the garden should not be done too quickly. They should have an acclimatization, or hardening off, period of 7 to 10 days during which they will be gradually exposed to outdoor conditions. Reduce the frequency of watering and put the pots outside for longer periods each day. They should be brought back in if the night-time temperature goes below 10°C. They should then be planted in the garden, with enough room to allow full development.

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