Where to sow
Where to sow
The subject "where to sow" is seldom discussed or described, but an item of great importance in our view. Probably the amateurs who are owners of a greenhouse will sow in the greenhouse.
Every cacti collection will have losses, especially at the end of the rest period when the resistance of the plants is low. Losses caused by fungi, bacteria or other organisms. These aggressors have their own ways to development, in order to reproduce themselves. They produce spores. These spores are hardly or sometimes not at all visible with the naked eye. They are so tiny that the slightest movement of air will spread them in the greenhouse.
Whichever method one uses to sow, every time the cover of the seed-box is lifted, the air will circulate thereby passing spores over the seedbed. The viral spores are capable to infect a healthy plant, contrary saprophytic spores, who live on dead material. This way causing the notorious "smolder". It is therefore advisable to place the seed-box at a location without plants or at least without cacti in the neighborhood.
This advice about the location is not based on suppositions, but on noted facts obtained by comparing the loss when placed in the greenhouse and those on other locations. To determine the loss requires a regular inspection of the seed-box and every pot with seedlings if possible daily. Otherwise the loss will pass unnoted as the seedling consist in early stage of a tiny drop of liquid covered with a cuticle. Within 24 hours 'there can be no trace left or hardly noted between the gravel of the seed bed.
Regarding the point in time of sowing we would like to note the following. When cultivating cacti and in particular the sensitive genera like the Discocacti and other Brazilian genera one has to look ahead in time. We would like to see a prosperous growth of the seedlings in the first year so it can enter the winter period without risk. It is therefore that we sow as early as possible in the year, around January/February. We can plant out the seedlings in April and May or graft them.
Years of experience have shown especially with the seedlings of the Discocacti that many die of rot and such like. This can be limited by keeping the vegetable mould or humus content as low as possible or to remove it completely and change to an inert substrate as mentioned earlier. But even then the loss is larger compared to other less fragile genera.
The above mentioned does not exclude that the cultivation by this method of plants of this genus on its own roots is possible But the risk of loss remains present and plants will seldom reach the age of those in nature. In general grafting is advised to obtain a better growth and development of the Discocacti.