In order to be as successful as possible when sowing date kernels, fresh, natural fruits should be planted.
The first thing that grows out of a date core is not the shoot, but the root. The core can be turned into any position during germination; the root will always grow downwards again, towards the center of the earth. In botany one speaks of a positive geotropic reaction in this regard. The plants are able to feel the gravity of the earth and to react to it. The sprout, which will appear soon after the root, will turn away from the center of the earth in the plumb line; it will react negatively geotropically if it is regularly illuminated from all sides. If it is only illuminated from one side, it will turn towards the light source; it behaves positively phototropically.
It is best to use fresh, natural dates for sowing, but you can also try dried and sugared fruits. After removing the pulp, the seeds are placed in a seed tray or a pot, which has already been filled with a layer of soil a few centimeters thick. We sprinkle another layer of soil about one centimeter thick over the seeds. It is advantageous if we use seed compost instead of normal potting compost. It contains only small amounts of fertilizer and therefore there is no risk that the young root roots will be burned by too high a salt content. With dates, it is also possible to use pure sand, because the seed contains enough reserve substances to feed the young plant until it is transplanted into nutrient-rich soil. In nature, where date palms usually germinate on very sandy soils or even on pure sand, this supply is also used. After sowing, we gently pour heated water and put the seed tray in a warm place with temperatures of 20 – 30 degrees. It would be good if the warmth came mainly from below, which works particularly well with a warming mat.
As soon as leaves appear, the location of the seedlings should be light and airy. The earth must not dry out; it is generally wrong to think that dates hardly need any water. In the deserts, namely, in oases where the soil is dry due to lack of or little rainfall, roots are driven many meters into deeper zones in places that carry water.
When the seedlings are one to two years old, they should be planted in pots. For the time being, those with a diameter of 10-12 cm are sufficient, clay pots being more suitable than plastic pots, as they allow gas exchange through the porous walls not only from above, but also from all sides. Roots also breathe and need fresh air.
The best time of year for potting and repotting is spring, when the roots start to grow again after the hibernation. We can now use normal, everywhere available potting soil, to which it is advantageous to add some sharp sand, in the ratio three parts potting soil to one part sand. We should repot every two to three years, because during this time the soil is used up and salts have accumulated through any fertilization with nutrient salts. We don’t have to use a larger pot every time we repot. Since palms grow rather weak, especially as young plants, the same pot can be reused for a few years. When repotting, the old soil must largely be removed from the root ball and damaged and dead roots cut away. It is important that excess irrigation water can always flow out of the hole in the ground immediately, which we achieve by first putting a 2 cm thick layer of broken stones into the pot before refilling it with new soil.
The new soil should only be lightly pressed down and – especially important – the base of the palm tree must never sit higher or lower than in the old pot.
Correct watering with the softest possible water requires a lot of feeling. Palms are neither aquatic plants nor succulents. The earth should be dry by the next watering, but not dried out. Every two months we put the whole pot in a water bath until no more air bubbles rise.
Since palms do not need as much nutrients as other plants, we fertilize carefully and sparingly. We can use saline liquid fertilizers or the less laborious saline slow-release fertilizers. Organic fertilizers that are easily worked into the surface are better. Soil organisms slowly break them down into substances that can be taken up by roots. The great advantage of organic fertilizers is that they do not over-salty the earth. You can wait longer before repotting. Date palms should be brought outdoors in full sun in summer. In winter, a light location is sufficient, where the temperatures are 5 ° – 15 ° C, i.e. not too high.