Some special problems during plant growing.
5. Surface sowing of seeds.
Some seeds need to be sowed on the soil surface exposed to the light, or they will not germinate. They then have dehydration problems. Examples are Impatiens and Pentas. The solution is to keep them in a sealed plastic box until they germinate. The problem now is that because they are on the surface, watering will knock them over and they will die. Either you water by mist-spraying, so the water droplets are too small to knock them over, or you water them from below e.g. by trickling water down the sides of the container. The soil then sucks up the water by capillary action. The problem now is that the young seedling is accustomed to a saturated humidity and needs to be "hardened off" = reducing the humidity over a period of days. 1st leave off the lid, but spray frequently and keep indoors; then put outside in deep shade; then the seedlings can be put in to plastic troughs, as in (1) above. |
6. Making a cutting.
Woody plants can be duplicated by cutting off a branch, the thicker the branch the better: - Cut diagonally (right side of stick in photo) to give a larger surface area. - Cut off all side branches and all leaves (which will otherwise lose water from the stick by transpiration). - Dip the cut end of the stick in water, then coat about 2 cm of end in a rooting hormone (white powder on right end of stick in photo). - Plant in a pot, being careful not to brush off the powder (so make hole in soil with your finger, not by pushing the stick in to the soil). Keep in the shade (or indoors if it is hot) to reduce water loss. - It may take a month for the cutting to take root and finally produce leaves (bottom photo) and much longer to get sufficiently established that it can be moved out in to the sun. |