Soil & potting mix
Best soil for Zantedeschia 'Edge of Night' (Zantedeschia 'Edge of Night')
Also called Edge of Night calla lily, deep purple calla.
More about zantedeschia 'edge of night'
About Zantedeschia 'Edge of Night'
Zantedeschia 'Edge of Night' · also called Edge of Night calla lily, deep purple calla · flowering
Zantedeschia 'Edge of Night' is a hybrid calla lily prized for near-black, velvety purple flowers above glossy spotted foliage. A tender tuberous perennial, it loves warmth, bright light and moist, fertile, well-drained soil. Lift the rhizome before frost in cold climates and store dry. Striking in containers and summer borders, it reaches around 50-60 cm.
Preferred mix: Rich, free-draining, moisture-retentive loam or quality potting mix
Watch for — Rhizome rot: Cold, wet, poorly drained soil rots the rhizome quickly. Plant in free-draining mix, avoid overwatering, and never leave tubers in waterlogged pots over winter.
Why zantedeschia 'edge of night' needs this mix
Zantedeschia 'Edge of Night' hates drying out, so it wants a mix that stays evenly moist — but it still needs perlite so "moist" never tips into "waterlogged".
- Zantedeschia 'Edge of Night' comes from damp, shaded forest floors and has fine roots that scorch and brown the moment the rootball dries — the mix has to hold a steady reserve.
- Coir and compost give that reserve, while perlite keeps enough air that the constantly-moist mix does not turn anaerobic.
- Even moisture also keeps its thin leaves from crisping at the edges, which is this plant’s most visible stress signal.
For the full picture on what makes up a good mix, see our guide to the main types of soil and potting media — it explains why each ingredient above behaves the way it does.
What goes wrong with the wrong mix
The wrong soil is one of the most common reasons zantedeschia 'edge of night' struggles, and the damage often shows up weeks later as a watering problem. For this species specifically:
- A free-draining, gritty mix dries too fast for zantedeschia 'edge of night' — you get crispy brown edges and frond or leaf drop within days of one missed watering.
- A pure, airless peat mix swings the other way: it holds water but suffocates the fine roots and rots the crown.
- Letting the mix dry to the point it shrinks from the pot is very hard to re-wet evenly and stresses the plant badly.
Using a sharp, fast-draining "houseplant" or cactus-leaning mix that lets zantedeschia 'edge of night' dry out. It needs a moisture-retentive but still airy blend.
pH — does it matter for zantedeschia 'edge of night'?
Zantedeschia 'Edge of Night' prefers a slightly acidic mix (around pH 5.5-6.5); a peat-free compost-and-coir blend sits there naturally, so routine pH testing is unnecessary.
If you want to check or adjust it, the soil pH guide walks through testing and the safe ways to nudge a mix more acidic or more alkaline.
DIY mix vs a bagged one
A good peat-free houseplant compost works for zantedeschia 'edge of night' straight from the bag if you mix in some perlite for air. The DIY ratio above gives a more reliable moisture-to-air balance.
Drainage and the pot
Use a pot with a drainage hole but a less-porous material (plastic or glazed) so it does not dry too fast. Bottom-watering keeps the mix evenly moist without sogging the crown.
Peat-free mixes slump and compact as they hold moisture, so refresh zantedeschia 'edge of night''s mix every 12-18 months to keep air in the rootball even if the pot size is unchanged. When the time comes, our repotting guide for zantedeschia 'edge of night' covers the timing and technique step by step.
Zantedeschia 'Edge of Night' soil — frequently asked questions
What is the best soil mix for zantedeschia 'edge of night'?
3 parts peat-free houseplant compost : 1 part coco coir : 1 part perlite. Zantedeschia 'Edge of Night' comes from damp, shaded forest floors and has fine roots that scorch and brown the moment the rootball dries — the mix has to hold a steady reserve.
Can I use normal potting soil for zantedeschia 'edge of night'?
A free-draining, gritty mix dries too fast for zantedeschia 'edge of night' — you get crispy brown edges and frond or leaf drop within days of one missed watering. A good peat-free houseplant compost works for zantedeschia 'edge of night' straight from the bag if you mix in some perlite for air. The DIY ratio above gives a more reliable moisture-to-air balance.
Does zantedeschia 'edge of night' need a special pH?
Zantedeschia 'Edge of Night' prefers a slightly acidic mix (around pH 5.5-6.5); a peat-free compost-and-coir blend sits there naturally, so routine pH testing is unnecessary.
Should I buy a bagged mix or make my own for zantedeschia 'edge of night'?
A good peat-free houseplant compost works for zantedeschia 'edge of night' straight from the bag if you mix in some perlite for air. The DIY ratio above gives a more reliable moisture-to-air balance.
How often should I refresh the soil for zantedeschia 'edge of night'?
Peat-free mixes slump and compact as they hold moisture, so refresh zantedeschia 'edge of night''s mix every 12-18 months to keep air in the rootball even if the pot size is unchanged. Use a pot with a drainage hole but a less-porous material (plastic or glazed) so it does not dry too fast. Bottom-watering keeps the mix evenly moist without sogging the crown.
Keep reading
- Zantedeschia 'Edge of Night' care — the full brief (light, water, humidity, problems, pet safety)
- How often to water zantedeschia 'edge of night' — the schedule the mix feeds into
- Repotting zantedeschia 'edge of night' — when and how to refresh the mix
- Soil pH guide — test it and adjust it safely
- Underwatered plant — signs and how to rehydrate it
- Why is my plant wilting? Wet vs dry diagnosis
- Should I water my plant? The simple check first
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