How Watercress propagates
Watercress (Nasturtium officinale W.T.Aiton, 1812) is a perennial plant of the Brassicaceae family and is often a spontaneous plant that lives along slow waterways, in semi-submerged and marshy soils.
It is an aquatic plant native to Europe and Asia; in Italy it is found in all regions on the banks of ditches and streams, from the plain to 1,500 meters.
Before moving on to the methods of propagation of this plant, consider that the cress is fairly resistant to the cold, requires average temperatures of about 15 degrees to live and germinates above 5 degrees.
Watercress can therefore be grown for most of the months of the year, avoiding the summer months where it is very hot and using protected cultivation (cold tunnel) for the winter months, especially in the vegetable gardens of northern Italy.
Watercress can also be grown in more mountainous areas as long as it is not exposed to excessive insolation and is planted on moist soil, well endowed with organic substance, even in pots but on a slightly acidic or neutral substrate with a pH between 6 and 7. The propagation can be carried out by seed or by division of the small tufts.
Propagation by seed –
Propagation by seed must be done taking into account that it can be done in stages, in the open field, starting from April, every 15 days, until June. The small reddish seeds of watercress germinate very quickly with temperatures above 15 ° C and within a couple of weeks it goes from sowing to harvesting the first small leaves.
In pot, sowing must be done in loose substrate (earth, peat and sand in equal parts) and transplanting the seedlings as soon as they have reached a height of 5-6 cm in small basins with a layer of soil at the bottom covered with a thin layer of gravel or expanded clay. Then add water, leaving only the apical part to emerge and place in a semi-shady place. Watercress is one of those plants that can be grown very well at home and ensure sufficient productions for family needs.
Watercress, due to its resistance to cold, can be cultivated under tunnels, even here with scalar sowing.
Even if it is possible to spread it, it is always advisable to plant it in rows, so that we can comfortably weed the weeds. The rows must be spaced 10-15 cm from each other, on the row the seeds are placed close to each other buried with just a veil of earth above. Non-woven fabric can be used to promote germination in the winter months, the cress germinates quickly so there is no need to plant it in a seedbed.
Propagation by tufts –
Even if the propagation technique by seed is the easiest one, both for the ease of taking root and the rapid growth of the plant, cress can be easily propagated by taking small tufts from spontaneous young plants. In this case, the collected tufts must be transplanted into organic soil which is always kept humid. It can also be sown in peat pots and then transplanted.
For the details of the cultivation technique, refer to the following sheet.