Recognize, prevent & fight root rot

Root rot often causes the dreaded end of dearly loved plants. We will show you how to correctly identify, prevent and combat root rot.

Not only the term root rot, but also that of the root killer is often used in connection with the diseased roots of our plants. Other synonyms for lazy roots are, for example, black-leggedness, neck rot or root blight. All of these names stand for the same phenomenon: Our plants have problems at the base, which often scares us gardeners. From the cultivated plants in the garden to large trees - all plants can ultimately be affected by and threatened by root rot. The root neck or the entire root system is often attacked and often only a soft, putrid mass remains.

What is behind the decaying and dying roots of our cultures? Usually bacteria and fungi are the culprits that cause this rot in the plant roots. In the following, we will reveal the exact causes of rot, how you can recognize it and what you can best do against root rot.

Causes of Root Rot

Root rot caused by fungi

Root fungi are pathogens that attack and damage the roots of plants. Above ground, root rot pathogens lead to wilting and Chlorosis, i.e. lightening or yellowing of the leaves. The most common root rot pathogens are different types of the classic fungus Pythiumor the egg fungus Phytophthora, but also many other fungi can cause rot on plant roots. Other known pathogens are Rhizoctonia, Fusariumor Phoma. However, an exact diagnosis is usually difficult because the root system is underground and the above-ground parts often show symptoms late. In the following we show you a list of common fungal diseases and how they manifest themselves:

Accidental sickness

• Seedlings turn black at the base, rotten and fall over
• Roots grow weaker and also get rotten
• Root bark is peeling off
• Plants wither, turn yellow and rotten
• Used mostly by mushrooms of the genus Pythium caused

Root tan

• Used by the soil-borne fungus Thielaviopsis basicolawho too Chalara elegans is called, caused
• Also known as root rot or black leggedness
• Roots turn brown, dry rot and the root tips remain white
• Leaves turn yellow, lag behind in growth, but do not die
• Often joins Cyclamen (Cyclamen), Chrysanthemums (Chrysanthemum), Pelargoniums (Pelargonium), Salads (Lactuca sativa), Tomatoes (Solanum lycopersicum), Legumes and elderberries (Sambucus) on
• at Carrots (Daucus carota subsp. sativus) this fungus causes rot in the warehouse - also known as "black carrot rot". With this carrot rot, the fungus also likes to kick Chalaropsis thielavioides as a secondary infection

Fusarium

• The pathogens penetrate the plants through the root tips or through wounds
• They clog the ducts and form toxic substances
• Trigger rot, including onion basal rot and root rot spinach (Spinacia) and Onions (Allium cepa)

Spot blight or hard rot

• Among others from Alternaria-Species caused (caused in potatoes Alternaria solani or Alternaria alternata spot blight and hard rot)
• Brown-black spots on the leaves, the stem also turns brown
• Dark, sunken areas form on the tubers and the potato tissue underneath becomes discolored, hard and dies

Root killer disease or black rot

• Lettuces start through Rhizoctonia solani to rot from the lower leaves
• Accumulating potatoes get spots on the stems and the base may turn brown
• A grayish-white coating forms at the base of the stalk of the potatoes, hence the name "Weißhosigkeit"
• The tubers are deformed, have spots and the tissue in the middle dies ("dry core", in German "dry core")

Pink root rot

• Used by different Phoma-Types raised
• Roots turn light pink to purple-brown
• Leaves change color and the plants can easily be pulled out of the earth
• Phoma betae causes root burn in beets, for example (beta) and can also cause storage rot

Aphanomyces rot

• For pulses such as Haricot beans (Phaseolus vulgaris) or peas (Pisum sativum) root rot or radish blackness develop
• Radish blackness is made from Aphanomyces raphani triggered
• Radish (Raphanus) turns blue-black from the outside in and rots
• After an infection, bacteria or often invade Rhizoctonia solani a

Root rot caused by bacteria

Bacteria often join in when rot occurs, but bacterial rot can also occur by itself in damp weather, for example through the following types:

• Erwinia-Species
• Pseudomonas-Species
• Rhizomonas-Species
• Xanthomonas-Species

An infection of the roots with bacteria is often promoted by a water build-up in the soil. Bacterial rot is therefore often referred to simply as wet rot or soft rot. Watery spots often develop Carrots, Onions and other subterranean plant parts. Wilt symptoms also appear and the plants begin to rot and disintegrate into a mushy form.

Leaf and tuber rot as a cause of root rot

This root rot in potatoes is triggered by Phytophthora infestans, but many fungi in the genus can cause root diseases in our crops. This mushroom is very well known as it caused great famine in the 19th century. Century. at potatoes (Solanum tuberosum) the stems turn brown and spots appear on the leaves. The herb eventually dries up and the tubers sink in and rot. For tomatoes (Solanum lycopersicum) the fungus causes the Late blight and brown rot. If you want to know more about this mushroom - Phytophtora infestans - you can find more information here.

Recognize and determine root rot

Because there can be so many different triggers for root rot, it is often difficult to identify the culprit. Often this is only possible under the microscope or in the laboratory. Typical signs of root rot, however, are initially wilting phenomena. Therefore, most of us water the plants even more, which then has exactly the opposite effect. Only when the plants have died and you take them out of the earth can you recognize the dead soft root material. Believe us: ornamental plants are watered to death far more often than they dry up.

In addition to the wilt, discoloration and chlorosis often appear on the leaves. The roots also often discolor and rot. It is not uncommon for the root neck to constrict, rot and discolour in the case of root rot. Infested plants can also be easily pulled out of the ground, as the roots are damaged or have already died and no longer offer enough support. As a result of this damage to the roots and the partially clogged vessels, the plants can no longer absorb their nutrients properly and then die.

Prevent and combat root rot

We have summarized the most important tips for you to prevent and control root rot on your plants:

Tip 1: avoid waterlogging

In general, environmental control can help prevent rot. Moisture and moisture promote fungal infections, so you should avoid waterlogging and keep the soil or substrate loose and well ventilated. The more solid and moist the soil, the more likely it is that root rot will occur.

Tip 2: pay attention to the sequence of crops

If you have root rot in the garden, you should definitely pay attention to your crop rotation for the next year. A certain pathogen often only grows on a certain crop or family of cultivated plants. So make sure you have some variety in the garden. If your potato rots, then avoid planting potatoes in this place the following year - it is best not to use any nightshades at all (Solanaceae) sit down there. With a varied crop rotation and loosening soil cultivation, you can prevent root rot well.

Tip 3: be careful with planters

With houseplants, cachepots are very decorative, but they can also be used to quickly drown your ornamental plants. In this way it is easy to overlook the fact that there is still water in the pot and unfortunately it quickly drowns your plants. In addition, the permanent moisture promotes infestation with root rot pathogens.

Tip 4: work on the soil

In the case of heavy garden soils, the introduction of sandy material or compost helps. Organic material promotes the build-up of humus and the ability to store water.

Tip 5: prevention instead of control

The use of fungicides is often not helpful, as these agents do not reach the fungi in the soil, but they do you can use various plant strengtheners that inhibit rot and promote healthy plant growth support financially. Unfortunately, there are a number of preventive measures that can be taken against root rot, but in acute cases it is usually too late. Therefore, pay attention to good soil conditions and crop rotation in your garden beds. You can prepare and protect your plants well with putrefactive agents.

Some extracts and teas can be used as a preventative against root rot, for example:

• Chamomile extract: For this anti-rot extract, you use a handful of dried ones Chamomile flowers (Matricaria chamomilla) and put them in 1 to 2 liters of water for a day. The extract should be diluted in a ratio of 1: 5 before use.
• Garlic tea: Chop about 300 g of garlic cloves and scald the garlic (Allium sativum) then with 5 liters of hot water. Then let it steep for a day and dilute the tea in a ratio of 1: 3. Dip the root ball of your plants in this tea before planting and thus prevent root diseases.
• Horsetail broth: 10 liters of water and 1 kg of fresher Horsetail (Equisetum) let stand for a day and then boil for half an hour. Dilute this broth in a ratio of 1: 5 and use against soil fungal diseases.

If your seedlings hang their heads or lie completely on the ground, the so-called "Accidental sickness”To blame. You can find out how you can prevent and combat these in our special article.