Early potatoes can really use some help getting started because they only have a short amount of time to form tubers. If they come into the prepared bed with long shoots, growth starts immediately. This valuable time saving also has a positive impact on the harvest.
When and how should you pre-germinate new potatoes?
Early potatoes should be pre-germinated about 4 to 6 weeks before the planting date. This is done by spreading the tubers on moistened soil in a fruit box and storing them at 15-20°C in a bright location, followed by cooler temperatures for hardening off.
These are the advantages of pre-germination
Pre-germinating potato seeds is not necessary for early varieties, even without this additional step nothing stands in the way of a good harvest. Nevertheless, the development lead brings two advantages that, considering the small amount of additional effort, are not to be despised:
- up to 20% higher crop yield
- up to 3 weeks earlier start of harvest
In addition, pre-germination ensures that the shell of the tubers becomes thicker more quickly. This makes the potatoes less susceptible to all kinds of pathogens that lurk in the soil.
The optimal time
You should encourage the tubers to pre-germinate about 4 to 6 weeks before the intended planting date. Since early potatoes usually come into the bed in April, pre-germination must begin in March. If you want to grow the potatoes in a greenhouse, you can even start 3 weeks earlier.
How to germinate the tubers
- Fill some compost or potting soil into a fruit box (€34.00 on Amazon) and then slightly moisten it.
- Distribute the seed tubers on top, most of the eyes should be facing upwards.
- Place the box with the tubers in a dry and bright location. A temperature between 15 and 20 °C is ideal.
- As soon as dark green, strong shoots appear, you should put the box cooler. Otherwise, at temperatures above 12 °C, the shoots would just become long and thin.
- When the germs have reached a length of around 3 cm, you should put the box a few degrees cooler again. This ensures that the potatoes are sufficiently hardened for their later stay outdoors.
The end of the germination period
Around mid-April the pre-germinated tubers are ready for planting. The germs are then several centimeters long and strong. Now the new potatoes just have to stay in the box until the outside temperature cooperates. The weather should be frost-free with at least 5 °C.
Tip
Sort out every tuber that has not yet sprouted. There is little chance that it will develop into a he althy potato plant out in the ground.
