Soil & potting mix
Best soil for Lungwort 'Mrs Moon' (Pulmonaria saccharata)
Also called Mrs Moon Lungwort, Bethlehem Sage, Jerusalem Cowslip.
More about lungwort 'mrs moon'
About Lungwort 'Mrs Moon'
Pulmonaria saccharata · also called Mrs Moon Lungwort, Bethlehem Sage · flowering
Lungwort 'Mrs Moon' is a classic spring-flowering shade perennial with heavily silver-spotted, semi-evergreen leaves and funnel-shaped flowers that open pink and age to blue-violet. An excellent ground cover for shaded and woodland borders. Prefers moist, humus-rich soil. Pet-safe according to ASPCA.
Preferred mix: Humus-rich, moisture-retentive loam or clay-loam
Watch for — Vine weevil: Adults notch leaf margins; larvae damage roots. Apply nematodes in late summer.
Why lungwort 'mrs moon' needs this mix
Lungwort 'Mrs Moon' hates drying out, so it wants a mix that stays evenly moist — but it still needs perlite so "moist" never tips into "waterlogged".
- Lungwort 'Mrs Moon' 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 lungwort 'mrs moon' 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 lungwort 'mrs moon' — 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 lungwort 'mrs moon' dry out. It needs a moisture-retentive but still airy blend.
pH — does it matter for lungwort 'mrs moon'?
Lungwort 'Mrs Moon' 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 lungwort 'mrs moon' 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 lungwort 'mrs moon''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 lungwort 'mrs moon' covers the timing and technique step by step.
Lungwort 'Mrs Moon' soil — frequently asked questions
What is the best soil mix for lungwort 'mrs moon'?
3 parts peat-free houseplant compost : 1 part coco coir : 1 part perlite. Lungwort 'Mrs Moon' 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 lungwort 'mrs moon'?
A free-draining, gritty mix dries too fast for lungwort 'mrs moon' — you get crispy brown edges and frond or leaf drop within days of one missed watering. A good peat-free houseplant compost works for lungwort 'mrs moon' 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 lungwort 'mrs moon' need a special pH?
Lungwort 'Mrs Moon' 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 lungwort 'mrs moon'?
A good peat-free houseplant compost works for lungwort 'mrs moon' 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 lungwort 'mrs moon'?
Peat-free mixes slump and compact as they hold moisture, so refresh lungwort 'mrs moon''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
- Lungwort 'Mrs Moon' care — the full brief (light, water, humidity, problems, pet safety)
- How often to water lungwort 'mrs moon' — the schedule the mix feeds into
- Repotting lungwort 'mrs moon' — 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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