The potato is not only one of the most popular vegetables in Germany, but also one with a long tradition. This power tuber is a staple food with an immense variety of varieties and it is impossible to imagine the kitchen without it. Their cultivation is extremely unproblematic. But the best thing about it is of course the potato harvest.
Harvest time depends on the variety
The various ripening groups play an important role in the ripening and harvesting time of potatoes. A distinction is made between very early to early, medium early and medium late to late varieties, as well as between waxy, predominantly waxy and floury. Basically, the annual potato harvest extends over several months, starting with the early potatoes in May/June and extending with the late varieties into October. You shouldn’t stubbornly stick to the calendar when harvesting potatoes, because the harvest dates can be slightly different. In addition to the ripening group, the soil, nutrient supply and weather conditions also have an influence on ripeness and thus also the harvest time.
Very early and early varieties
Early potato varieties such as ‘Sieglinde’, ‘Belana’, ‘Gala’, ‘Natascha’, ‘Annabella’ or ‘Cilena’ can only be stored to a limited extent and should therefore always be harvested as required. Early varieties reach maturity after about 110-120 days. They differ from later varieties in that they have less starch, a more limited shelf life, and a thinner skin that can be eaten in moderation. But they contain more water and a little more nitrate. In order to optimize the harvest of new potatoes, these varieties are usually pre-germinated. Harvest time is already in June/July. With a few exceptions, they are predominantly waxy.
Medium-early potatoes such as ‘Allians’, ‘Agria’, ‘Nikola’, ‘Hansa’ or ‘Blauer Schwede’ make up the largest group of varieties. Their shell is already much firmer, making them perfect for longer storage. These so-called cellar potatoes can be kept for at least the end of the year, provided they are stored appropriately. It usually takes between 120 and 140 days from planting to harvest. Harvest time for these varieties is around July/August.
Mid-late and late varieties
Medium late and late varieties such as ‘Fasan’, ‘Jelly’, ‘Cascada’, ‘Adretta’ ‘Panda’ or the particularly popular ‘Laura’ take the longest from planting to ripening or harvesting at 140-160 days . On the other hand, they are particularly productive and are very well suited for long storage until next spring. Harvest time for these late varieties is around September/October, in any case before the first frost.
Tip: If you don’t want to store large quantities and like variety, you can grow several varieties with different levels of maturity and thus harvest over a longer period of time.
Signs of ripeness of potatoes
The ripeness is also determined by the respective variety. As long as the herb is still green, the tubers continue to grow and store starch. They can also be harvested and eaten when part of the herb is still green. However, they are not yet suitable for storage at this point in time.
- Potatoes are ripe when the leaves have died
- Do not confuse maturity with late blight
- Tubers are easy to detach from the plant
- Shell is thicker and no longer easy to peel off
- Only gets thicker after the herb has died
- Solid shell indispensable for long-term storage
- To test, carefully dig up a tuber two weeks after it has died
Potato Harvest – Instructions
When the time has finally come, you first need a digging fork or a special potato hoe. Spades are unsuitable for the potato harvest because they could damage the potatoes. In addition to the right tool, you should choose a day that is as dry as possible for the harvest. To be on the safe side, you can dig up another plant to try it out.
- Leave storable varieties in the ground for as long as possible
- The longer they are in the ground, the stronger and more resilient the shell
- Gradually harvest new potatoes
- For immediate consumption, some of the foliage may still be green
- New potatoes are then particularly tender
- Tubers remaining in the ground, always cover well with soil
- Light causes the tubers to turn green
- Green parts contain the toxin solanine
- When harvesting potatoes, place the digging fork at a distance from the plant
- Distance is to avoid injury to the tubers
- Insert a fork deep into the ground and lift out the plant and potatoes
- Some tubers hang directly on the plant when you dig them up
- Can be easily removed
- To harvest those remaining in the ground, carefully dig up again
- Remaining potatoes come to the surface and can be picked up
When the potato harvest is complete and all the tubers have been salvaged, they are left on the bed to dry well. If the moist tubers were to be stored immediately, rotting would occur relatively quickly. As soon as they are well dried, they are roughly cleaned or loose soil is removed and the potatoes are stored. They should be well dried before storing, but not exposed to light for too long, because then there is a risk of green spots forming again.
Tip: Smaller green areas can be generously cut out before consumption, as can the beginnings of germination. If they already predominate, the potatoes in question are no longer suitable for consumption and should be discarded.
Forge potatoes for an early harvest time
By forcing, especially very early or early potatoes, the potato harvest can be brought forward by about two to three weeks. Of course, you can also promote medium-early varieties if you want to. Pre-germinated potatoes have the advantage that they grow better, are ready to harvest faster and are less susceptible to diseases. Their shell hardens faster, which in turn makes it difficult for fungi and soil pests to penetrate.
For pre-germination, place early potatoes from February and medium-early ones from March, next to each other in shallow fruit jars filled with potting soil and ripening compost. You then put them in a bright and dry place with temperatures of 10-14 degrees.
Increase yield by piling
Piling up plays an important role in potato cultivation and especially in increasing yield. As a result, the tubers are optimally protected from the effects of light, cold and possible late frosts. As soon as the young potato plants are about 20 cm high, the soil between the rows of potatoes is pulled up to the plant with a hoe or a rake so that the stalks are about half covered with soil.
On the stem area, which is then covered with soil, so-called adventitious roots develop, on which further tubers form. About 3-4 weeks later, the potatoes, which have now grown significantly, should be piled up again to encourage the plants to form more adventitious roots. When piling up, care should always be taken that no potatoes are exposed. They should be well covered with soil at all times.
Tip: If you want to maximize the yield even further, you can mulch the potatoes with a thick layer of mature compost and semi-decomposed autumn leaves after they have been piled up again. In this way, the heavy feeders are additionally supplied with nutrients.
Intact or damaged tubers should already be sorted out during the potato harvest, because only undamaged ones are suitable for storage. Damaged specimens do not have to be disposed of, they are still suitable for consumption in the near future. Tubers with green parts should also be sorted out.
- Only use mid-early and late varieties for storage
- Mid-early are the actual storage potatoes
- Unheated basement well suited as a storage location
- It should be dark, cool and well ventilated
- Temperatures of four to six degrees are ideal
- If it is significantly cooler, potatoes will taste slightly sweet
- If the temperature is too low, starch is converted into sugar
- Temperatures of more than eight degrees allow potatoes to germinate early
- Consumption of sprouted tubers is not recommended
- If necessary, use as seed potatoes
- Store tubers in fruit trays, potato hoards, vegetable boxes or on slatted frames
- Storage in metal or plastic containers is not recommended
If necessary, the potatoes can be stacked at a height of about 40 cm. Covering with jute, newspaper, or sand dampened from the cellar can prevent the tubers from prematurely shrinking due to moisture loss.
Tip: Storage in the immediate vicinity of apples or pears should be avoided. These fruits, like some others, exude the ripening gas ethylene, which would accelerate spoilage of the tubers.
Factors that can endanger the harvest
Just as there are factors that can increase yield, there are also those that can compromise the potato harvest. These include the dreaded late blight and brown blight and the potato beetle.
- Late blight occurs mainly in warm, humid autumn and late autumn
- Leaves initially turn yellow
- In the later course, gray or brown spots
- Stems and leaves die off within a few days
- Wilted leaves easily confused with natural ripening of the potato
- At the first sign, harvest the potatoes immediately
- Spread of this fungal disease, so possibly preventable
The Colorado potato beetle is somewhat less dangerous for the potato harvest, although it can also cause considerable damage if left unchecked. This can be done by removing and disposing of leaves containing the beetles’ clutches and collecting both the beetles and their larvae regularly. The beetle is yellow with black spots on its pronotum and dark longitudinal stripes on its wings.