Soil & potting mix
Best soil for Sticky Jerusalem Sage (Phlomis viscosa)
Also called Sticky Jerusalem sage, Viscous phlomis.
More about sticky jerusalem sage
About Sticky Jerusalem Sage
Phlomis viscosa · also called Sticky Jerusalem sage, Viscous phlomis · flowering
Phlomis viscosa is a robust, glandular-sticky perennial or short-lived sub-shrub native to the eastern Mediterranean, from Israel and Lebanon through Turkey and Cyprus, growing on rocky, dry slopes and garrigue. It produces bold whorls of golden-yellow hooded flowers above large, sticky, rugose leaves that trap dust and insects. The key care rule is excellent drainage — soggy winter soil quickly kills the rootstock. Pet-toxicity status is not confirmed by the ASPCA; treat as mildly toxic out of caution.
Preferred mix: Free-draining, poor to moderately fertile, alkaline or neutral
Watch for — Root and crown rot in wet winters: The most serious threat in UK gardens and wet-winter climates; plant in full sun on free-draining soil or raised beds, and do not mulch over the crown.
Why sticky jerusalem sage needs this mix
Sticky Jerusalem Sage is a Mediterranean dry-hillside plant — it wants a lean, sharply drained, slightly alkaline mix, and rots fast in rich, water-holding soil.
- Sticky Jerusalem Sage evolved on stony, sun-baked slopes — its roots expect to dry out hard and quickly between rains, so the mix must drain almost as fast as you pour.
- A lean, low-nutrient mix keeps growth firm and aromatic; a rich one gives soft, sappy, flavourless growth that flops and rots.
- It tolerates and often prefers a slightly alkaline soil, the opposite of most houseplants.
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 sticky jerusalem sage struggles, and the damage often shows up weeks later as a watering problem. For this species specifically:
- Rich, moisture-holding compost is the classic killer of sticky jerusalem sage — especially over a cold, wet winter, when the base of the plant simply rots.
- A peaty, acidic potting mix is doubly wrong: too wet and the wrong pH direction.
- No grit means the rootball stays damp for days, which a dry-climate root system never copes with.
Growing sticky jerusalem sage in ordinary rich, moisture-retentive compost. Lean it out with at least a third grit, and never let it sit wet over winter.
pH — does it matter for sticky jerusalem sage?
Sticky Jerusalem Sage likes neutral to slightly alkaline soil, roughly pH 6.5-7.5. If your soil or compost is acidic, a little garden lime or extra grit nudges it the right way — the one common plant where you may add lime.
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
Bagged "herb" or "Mediterranean" mixes are usually fine for sticky jerusalem sage, but most standard composts need cutting hard with grit. The DIY ratio above is cheap and exactly right.
Drainage and the pot
Sharp drainage is everything: a terracotta pot with a big hole, gritty mix and never a saucer left full. Raised beds suit these herbs outdoors for the same reason.
A gritty mix barely breaks down, so sticky jerusalem sage needs little repotting — refresh the top layer and the grit every couple of years rather than potting on aggressively. When the time comes, our repotting guide for sticky jerusalem sage covers the timing and technique step by step.
Sticky Jerusalem Sage soil — frequently asked questions
What is the best soil mix for sticky jerusalem sage?
2 parts standard peat-free compost or loam : 1 part coarse horticultural grit : 1 part perlite or coarse sand. Sticky Jerusalem Sage evolved on stony, sun-baked slopes — its roots expect to dry out hard and quickly between rains, so the mix must drain almost as fast as you pour.
Can I use normal potting soil for sticky jerusalem sage?
Rich, moisture-holding compost is the classic killer of sticky jerusalem sage — especially over a cold, wet winter, when the base of the plant simply rots. Bagged "herb" or "Mediterranean" mixes are usually fine for sticky jerusalem sage, but most standard composts need cutting hard with grit. The DIY ratio above is cheap and exactly right.
Does sticky jerusalem sage need a special pH?
Sticky Jerusalem Sage likes neutral to slightly alkaline soil, roughly pH 6.5-7.5. If your soil or compost is acidic, a little garden lime or extra grit nudges it the right way — the one common plant where you may add lime.
Should I buy a bagged mix or make my own for sticky jerusalem sage?
Bagged "herb" or "Mediterranean" mixes are usually fine for sticky jerusalem sage, but most standard composts need cutting hard with grit. The DIY ratio above is cheap and exactly right.
How often should I refresh the soil for sticky jerusalem sage?
A gritty mix barely breaks down, so sticky jerusalem sage needs little repotting — refresh the top layer and the grit every couple of years rather than potting on aggressively. Sharp drainage is everything: a terracotta pot with a big hole, gritty mix and never a saucer left full. Raised beds suit these herbs outdoors for the same reason.
Keep reading
- Sticky Jerusalem Sage care — the full brief (light, water, humidity, problems, pet safety)
- How often to water sticky jerusalem sage — the schedule the mix feeds into
- Repotting sticky jerusalem sage — when and how to refresh the mix
- Soil pH guide — test it and adjust it safely
- Overwatered plant — signs and recovery
- Root rot — how the wrong soil starts it, and how to save the plant
- Should I water my plant? The simple check first
- Best soil for violet petunia
- Best soil for wave purple petunia
- Best soil for supertunia bubblegum petunia
- All 10153 soil and potting-mix guides in the Growli library