How to grow nasturtiums from seed (Tropaeolum)
Although many annuals can be sown directly in the garden, sowing early seeding in a sheltered location gives the plants an advance in growth and a more assured germination that generally produces better results. In this article, we will learn step by step how to grow nasturtiums from seed (Tropaeolum) – in this guide Nasturtium ‘Empress of India’.
Seeds can be sown in pots in a greenhouse or cold frame or even inside in a sunny window sill.
You can buy nasturtium seeds in garden centers or even in supermarkets. Check the package if the seeds are within expiration date and if it is sealed and in good condition. If you need to store seeds for some time, do so in a cool, dry place.
Nasturtium seeds are relatively large and easily handled.
When to sow
Nasturtiums can be sown from late winter to mid spring. You can start them earlier in a sheltered place.
How to sow nasturtiums
Fill small pots with good quality compost, leaving some space below the pot edge. Lightly press the soil to make it firmer.
Put the seeds in the pots. Do not sow too much tighter. Nasturtium seeds germinate easily and will be transplanted, so 2 to 3 seeds per 9cm pot is the limit. If you can, sow individually.
Then cover the seeds with more soil and water with a fine-grained watering can. Alternatively, you can gently dip the pots into a tray with water so that the soil absorbs moisture.
How to plant nasturtium
When the seeds have already developed some leaves, it is time to get them outside (if there is no longer any danger of frost). If they’re already outdoors, then it’s time to plant them in their final location.
In this case, we are going to plant nasturtiums in an old terracota pot. We fill the pot with universal compost leaving the space necessary to plant the plants at the same depth and leave space for watering.
We carefully separate the small plants so as not to disturb the roots too much and plant them covering the roots with soil. In this case we are putting 4 plants in the pot, but 2 would be enough as nasturtiums are very vigorous plants.
Finally, water the pot and place it in a sunny place. Nasturtiums love the sun.
This plant flowered 7 weeks after sowing.
Did you like our step-by-step guide to sowing nasturtiums? Tell us about your experience with this plant and where you like to plant it.