Soil & potting mix
Best soil for Besom heath (Erica scoparia)
Also called Besom heath, Green heather, Broom heath.
More about besom heath
About Besom heath
Erica scoparia · also called Besom heath, Green heather · flowering
A tall, upright western Mediterranean heath grown chiefly for its airy, needle-like dark green foliage and architectural form. Small, greenish-brown bell-shaped flowers appear in late spring and early summer, releasing pollen in clouds. Fully hardy (RHS H5), it tolerates exposed sites and poor, acidic, sharply drained soils. Historically used to make brooms and is the source of briar pipe root burls in some regions.
Preferred mix: Acidic, well-drained to dry sandy or loamy soil
Watch for — Phytophthora root rot: The primary threat in poorly drained or heavy soils. Plants wilt, collapse, and show black rotting roots. Ensure sharp drainage from the outset; plant on raised mounds in heavy soils. No cure — remove affected plants and avoid replanting in waterlogged areas.
Why besom heath needs this mix
Besom heath is a true acid-lover — it physically cannot take up iron above about pH 5.5, so an ericaceous mix is not optional, it is survival.
- Besom heath has evolved on acidic, peaty ground and depends on soil fungi that only function in acid conditions — raise the pH and it starves even in "rich" soil.
- In a too-alkaline mix iron and manganese lock up chemically, so the youngest leaves yellow between green veins (lime-induced chlorosis) and the plant fades out.
- Its fine, shallow roots also want an open, free-draining structure, not a heavy clay or claggy compost.
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 besom heath struggles, and the damage often shows up weeks later as a watering problem. For this species specifically:
- Ordinary multipurpose or garden compost is far too alkaline for besom heath — expect classic yellowing, weak growth and a slow decline over a season or two.
- Hard tap water slowly pushes the pH up too, undoing a good mix; rainwater is strongly preferred for watering.
- Lime, mushroom compost or wood ash anywhere near this plant is actively harmful.
Planting besom heath in standard compost or limey garden soil. Without an acidic (ericaceous) medium it will yellow and fail no matter how well you water and feed it.
pH — does it matter for besom heath?
This is the whole game: Besom heath needs pH 4.5-5.5. Test it, use ericaceous compost (and an ericaceous feed), and water with rainwater where you can to keep the pH from creeping up.
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 ericaceous compost is the correct, easy base for besom heath; just open it up with bark and grit per the ratio above. Do not try to acidify ordinary compost by guesswork — it rarely holds.
Drainage and the pot
Containers are often easier than open ground because you control the pH completely. Use a pot with good drainage and an ericaceous mix; never let it sit waterlogged.
Top up or refresh the ericaceous mix yearly and test the pH each spring — it naturally drifts upward over time, especially if watered with tap water. When the time comes, our repotting guide for besom heath covers the timing and technique step by step.
Besom heath soil — frequently asked questions
What is the best soil mix for besom heath?
3 parts ericaceous (acidic) compost : 1 part composted pine bark or pine needles : 1 part perlite or coarse grit. Besom heath has evolved on acidic, peaty ground and depends on soil fungi that only function in acid conditions — raise the pH and it starves even in "rich" soil.
Can I use normal potting soil for besom heath?
Ordinary multipurpose or garden compost is far too alkaline for besom heath — expect classic yellowing, weak growth and a slow decline over a season or two. Bagged ericaceous compost is the correct, easy base for besom heath; just open it up with bark and grit per the ratio above. Do not try to acidify ordinary compost by guesswork — it rarely holds.
Does besom heath need a special pH?
This is the whole game: Besom heath needs pH 4.5-5.5. Test it, use ericaceous compost (and an ericaceous feed), and water with rainwater where you can to keep the pH from creeping up.
Should I buy a bagged mix or make my own for besom heath?
Bagged ericaceous compost is the correct, easy base for besom heath; just open it up with bark and grit per the ratio above. Do not try to acidify ordinary compost by guesswork — it rarely holds.
How often should I refresh the soil for besom heath?
Top up or refresh the ericaceous mix yearly and test the pH each spring — it naturally drifts upward over time, especially if watered with tap water. Containers are often easier than open ground because you control the pH completely. Use a pot with good drainage and an ericaceous mix; never let it sit waterlogged.
Keep reading
- Besom heath care — the full brief (light, water, humidity, problems, pet safety)
- How often to water besom heath — the schedule the mix feeds into
- Repotting besom heath — when and how to refresh the mix
- Soil pH guide — test it and adjust it safely
- Root rot — how the wrong soil starts it, and how to save the plant
- Underwatered plant — signs and how to rehydrate it
- Should I water my plant? The simple check first
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- All 8452 soil and potting-mix guides in the Growli library