Deadly Webcap
Cortinarius rubellus
Cortinarius rubellus, commonly known as the Deadly Webcap, is a highly toxic mushroom found in forested areas. Its unique appearance and ecological role make it a fascinating subject for study, though it is not suitable for home cultivation due to its toxicity.
Everything it needs
9 essentials at a glance
Watering
Cortinarius rubellus prefers moist soil but should not be overwatered.
Water when the top inch of soil feels dry, typically every 1-2 weeks, depending on humidity and temperature. Signs of overwatering include yellowing leaves and root rot, while underwatering may cause wilting and browning edges.
Light
This species thrives in partial shade, ideally receiving 4-6 hours of indirect sunlight daily.
It can tolerate some full sun but is best placed where it receives filtered light, such as under trees or in shaded garden beds.
Soil
Cortinarius rubellus prefers well-draining, acidic soil with a pH range of 5.0 to 6.5.
A mix of peat, pine needles, and sand is recommended to ensure good drainage while retaining moisture.
Humidity
This plant enjoys high humidity levels, ideally between 60-80%.
To increase humidity, mist the plant regularly or use a humidity tray. Signs of low humidity include browning leaf tips and leaf drop.
Temperature
The ideal temperature range for Cortinarius rubellus is 60-75°F (15-24°C).
It is typically found in hardiness zones 5-8 and can tolerate cooler temperatures but should be protected from frost.
Fertilizing
Use a balanced fertilizer with an NPK ratio of 10-10-10, applying every 4-6 weeks during the growing season.
Signs of nutrient deficiency include stunted growth and pale foliage.
Pruning
Pruning is not necessary for Cortinarius rubellus, but removing dead or damaged leaves can help maintain the plant's health.
Use clean, sharp scissors to make clean cuts and avoid damaging surrounding foliage.
Repotting
Repotting is necessary every 2-3 years or when the plant outgrows its pot.
Signs include roots growing out of the drainage holes and stunted growth. Choose a pot one size larger, and gently loosen the roots before placing it in fresh soil.
Propagation
Propagation is typically done through spores rather than traditional methods like cuttings or division.
Collect spores from mature caps in the fall, then sow them in a suitable substrate. This process is best undertaken in late summer to early fall.
When it's unhappy
Yellowing leaves
Why it happens
Often caused by overwatering or nutrient deficiency.
How to fix it
Adjust watering schedule and check soil nutrients, applying fertilizer if necessary.
Root rot
Why it happens
Excess moisture in the soil due to overwatering.
How to fix it
Allow the soil to dry out and improve drainage; consider repotting in fresh soil.
Browning leaf tips
Why it happens
Low humidity levels or underwatering.
How to fix it
Increase humidity through misting or using a humidity tray, and adjust watering frequency.
Wilting
Why it happens
Underwatering or extreme temperature fluctuations.
How to fix it
Check soil moisture and water thoroughly if dry, and ensure the plant is in a stable environment.
Stunted growth
Why it happens
Nutrient deficiency or poor soil quality.
How to fix it
Fertilize with a balanced fertilizer and consider repotting in a nutrient-rich mix.
Care through the year
Spring
In spring, focus on ensuring adequate moisture as the plant begins to grow. Monitor for pests and adjust watering as temperatures rise.
Summer
During summer, maintain high humidity and ensure the plant is not exposed to direct sunlight for extended periods. Water regularly to keep the soil moist.
Fall
In fall, prepare for dormancy by reducing watering slightly. This is also the best time for collecting spores for propagation.
Winter
In winter, protect the plant from frost and cold drafts. Water less frequently, allowing the soil to dry out slightly between waterings.
Toxicity & Safety
Cortinarius rubellus is highly toxic, containing deadly compounds that can cause severe gastrointestinal distress and kidney failure if ingested. All parts of the plant are considered dangerous, particularly the caps and gills.
Good to know
Why are my Cortinarius rubellus leaves turning yellow?
Yellowing leaves can indicate overwatering or a lack of nutrients. Check the soil moisture and consider fertilizing if necessary.
How often should I water my Deadly Webcap?
Water your Cortinarius rubellus when the top inch of soil feels dry, typically every 1-2 weeks, adjusting based on humidity and temperature.
What type of soil is best for Cortinarius rubellus?
This plant thrives in well-draining, acidic soil with a pH of 5.0 to 6.5, such as a mix of peat, pine needles, and sand.
How can I increase humidity for my Deadly Webcap?
To increase humidity, mist the plant regularly or place it on a humidity tray filled with water and pebbles to create a more humid microenvironment.
When is the best time to propagate Cortinarius rubellus?
The best time to propagate is in late summer to early fall when the spores are mature and ready for sowing.
What are the signs of root rot in Cortinarius rubellus?
Signs of root rot include yellowing leaves, wilting, and a foul smell from the soil. If you notice these symptoms, check the roots and adjust watering.
Is Cortinarius rubellus safe for pets?
No, Cortinarius rubellus is highly toxic to pets and humans. All parts of the plant can cause severe health issues if ingested.
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