Fertilizing raspberries: 5 home remedies | Coffee grounds, nettle liquid & co

Not only the composition of the fertilizer, but also the timing of fertilization has a major impact on the health of the plant and a plentiful harvest. In general, raspberry plants are fertilized when they are planted. In the case of nutrient-poor soils, further fertilizers are then advisable in spring and possibly again in late summer.
Fertilize in spring

• Time: April to the beginning of May at the latest
• before flowering
• never fertilize while the fruit is ripening
• otherwise the fruits will become watery

Second fertilization

Too much fertilizer is almost more harmful than too little. Therefore, a second fertilization is only appropriate on very poor soil. This takes place after the fruiting period in July or August and serves to give the plant strength for the upcoming winter.

• after fruit ripening
• Raspberries or summer raspberries bearing once: mid to late July
• Autumn raspberries or multiple bearing varieties: August
• Fertilizer must only contain a small amount of nitrogen
• Do not fertilize late-bearing varieties a second time

Spread fertilizer

When fertilizing, of course, the appropriate form (solid, liquid) and the effects of the weather must be taken into account.

Liquid fertilizer:

• move in quickly
• Nutrients are in a water-soluble form
• are immediately available to the plant
• are quickly washed out by the rain
• therefore do not last long
• multiple fertilization in a weekly rhythm
• Duration: a maximum of 4 weeks (in spring)

Solid fertilizers:

• the nutrients usually have to be released by rotting
• work into the ground
• release nutrients slowly
• are considered long-term fertilizers
• one-time fertilization

Fertilize raspberries with home remedies

Basically, it should be noted that a fertilizer without chloride is used, because raspberries do not tolerate this substance particularly well. All home remedies that contain table salt are therefore unsuitable. Also refrain from liming the soil or introducing substances that increase the pH value. High levels of lime in the soil prevent the plant from growing vigorously and reduce the yield. Home remedies that can be used in large quantities without any problems and that do not lead to overdosing quickly have proven to be effective. Organic fertilizers that slowly decompose in the soil are therefore ideal.

Nettle manure

Stinging nettles need a lot of nitrogen to grow. Because of this, the rotting plant material is also a good source of nitrogen and can be used as a natural fertilizer for raspberries. To prepare a liquid manure, the roughly chopped leaves and stems are just covered with water in a bucket or tub and left to stand for one to two weeks, depending on the temperature.

• all parts of the plant suitable except for the roots
• coarsely chop
• Use a container made of plastic or wood (no metal)
• cover with water
• cover with a board or lid
• do not close airtight
• when rotting, gases are formed
• stir daily

The nettle manure is ready for use when the foam that forms on the liquid in the bucket does not rise any further. To fertilize the raspberry bushes, it is diluted 1:10 with water and poured onto the roots of the plants. Because of the high nitrogen content, use nettle manure only in low doses and only in spring.

Coffee grounds

Coffee grounds are an inexpensive alternative to purchased fertilizers for berry bushes. It is rich in nitrogen, phosphorus, potassium and other minerals and especially cheap because it is a waste material. The cold powder can be worked into the soil in spring. Since coffee grounds go moldy very quickly, they should not be used fresh as the wet powder will clump and mold. Spread the coffee grounds out on newspaper and place them in a well-ventilated area to dry. The coffee grounds should be worked well into the soil for fertilization.

• dry first
• can be stored for a few weeks (in a closed container)
• Use fresh only when planting or repotting
• acts as a slow release fertilizer
• attracts earthworms
• loosens the soil
• keeps the pH value in the soil optimal (slightly acidic)
• good source of potassium (also suitable for autumn fertilization)
• Odor scares off pests

Wood ash

Wood ash is a good supplier of nutrients and, under certain circumstances, is also suitable for fertilizing raspberry bushes. However, due to the high calcium content, wood ash increases the pH value in the soil. However, since raspberries prefer a soil pH of 5.5 to 6, i.e. slightly acidic, wood ash should only be added to acidic soils – and only to a small extent. The advantage of wood ash is obvious: you can easily produce it yourself and it is easy to store. If you want to use wood ash from a fireplace to fertilize plants in your garden, make sure that the wood has not been treated or processed. The following are unsuitable for fertilizing raspberry bushes:

• glazed or lacquered wood
• impregnated boards or battens
• Charcoal or briquettes (often contain heavy metals)

So only use untreated wood, for example logs for the wood stove in the house. In order not to add any substances that the raspberries cannot tolerate, you should not use conventional grill or oven lighters, but only pollutant-free wood wool or paper (no colorfully printed magazines or glossy magazines).

• a maximum of 30 g of wood ash per square meter
• Slurry in water in strong winds

Cooking water from potatoes and vegetables

An old home remedy for fertilizing raspberries is the water in which potatoes or vegetables have been boiled. During the cooking process, minerals and other nutrients from the vegetables dissolve in the water. All you need to do after boiling is to collect the water and let it cool down. You can then water your raspberry bushes with it. Since no large amounts of nutrients are released from the potatoes or vegetables, you should water with the brew on a weekly basis during the growing season.

Compost

In nature, raspberries grow in or near forests. Good forest soil is an excellent source of the nutrients a raspberry bush needs. Forest soils have a high proportion of humus, which consists of leaves, wood and dead plants and which are decomposed by soil organisms. Most of the soils in the garden are too poor for raspberries or do not contain enough humus, which not only provides important nutrients, but also creates an optimal environment for the plant, as it stores water well, for example. An optimal fertilizer for raspberries is therefore ripe compost, which is produced in many gardens anyway.

• work into the soil in spring or autumn
• use when planting
• no over-fertilization possible
• do not use on floors that tend to become waterlogged

Conclusion
Organic fertilizers are particularly suitable for fertilizing raspberries. As a home remedy, herbal raw materials are therefore perfect as they slowly rot in the earth and release the nutrients over a period of months. You should be careful with all home remedies that contain high salt contents or increase the pH value in the soil.