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Grow mushrooms indoors UK: choosing the right room

Updated: October 2026

You can grow mushrooms indoors in a UK flat without a garden, if you start with a ready culinary kit and give it a stable place away from hard sun and central heating. A shelf in a bright room often works better than the obvious windowsill, because it gets indirect light without the same heat and overnight swings. Among the products in the [mushroom culture comparison](/hub/seeds-and-plants/mushroom-culture), the Carbeth Plants shiitake kit is the only named ready kit with a clear indoor claim. The substrate bags still need culture, and the chicken-of-the-woods syringe points towards hardwood rather than a shelf crop. Room choice comes after product type. A qualifying purchase can earn a commission at no extra cost to you.

You can grow mushrooms indoors in a UK flat without a garden, if you start with a ready culinary kit and give it a stable place away from hard sun and central heating.

Our top picks

Fat Fungi Fat Fungi rye and CVG bag

Best overall

Fat Fungi Fat Fungi rye and CVG bag
8.2/10about £12.99
View offer
Carbeth Plants Carbeth Plants shiitake kit

Rank 2

Carbeth Plants Carbeth Plants shiitake kit
6.6/10about £19.99
View offer
liquidmushrooms.co.uk Chicken of the woods liquid culture

Alternative

liquidmushrooms.co.uk Chicken of the woods liquid culture
1.0/10about £7.49
View offer
On this page
  1. 1.A flat can host a ready mushroom kit
  2. 2.Indirect light is useful; direct sunshine is not
  3. 3.Manage heat and dry air without one perfect temperature
  4. 4.Which of these listings belongs indoors?

A flat can host a ready mushroom kit

A ready kit brings a colonised block, so it does not need soil or a garden. You need a clean surface, indirect daylight and room for air to move. A kitchen, utility room or bathroom can work. The label and the daily conditions matter more than the room's name. Carbeth says its shiitake kit can be grown indoors through the year, in a kitchen, a utility room or on a windowsill. That is the clearest flat-friendly item here, and it is not a crop guarantee. The listing is 3.3 from nine ratings, with both a reported crop and reports of none. Check the block on arrival. The Fat Fungi bags are not substitutes. The rye bag says to add spores. The manure bag includes no culture and names no species. A good shelf does not supply the missing fungus. If you are still choosing a format, use the mushroom culture buying guide first.

Indirect light is useful; direct sunshine is not

Mushrooms do not photosynthesise like green plants, yet UK kit makers use indirect light as a cue. Caley Brothers wants natural light without direct sun, and Which? describes a light, ventilated room. A shelf set back from the window is easier to control than the glass. Carbeth names a windowsill. Merryhill advises against windowsills for its kits because direct sun and day-to-night swings can dry the block. A deep shaded sill may stay stable. A south-facing sill above a radiator can become hot within an hour. Follow Carbeth's insert, then judge the actual light and heat. Move the kit if the sun reaches it or the surface dries soon after misting. A dark cupboard can restrict air and hide contamination. Use the maker's enclosure. Do not seal a fruiting block in a box just to hold humidity.
Fat Fungi Fat Fungi rye and CVG bag

Testsieger

Fat Fungi Fat Fungi rye and CVG bag
8.2/10about £12.99
View offer

Manage heat and dry air without one perfect temperature

No temperature is printed for the Carbeth kit. Merryhill gives 14–21°C for its own kits, Caley Brothers roughly 15–24°C, and Falfungi about 19°C. Those figures are not a Carbeth specification. A radiator and a hob are the clearer hazards. They make local hot, dry air. Move the kit rather than spraying constantly. A utility room can work if it has indirect daylight and does not overheat when a dryer runs. A bathroom can be humid only with light, ventilation and no aerosol cleaner near the block. Harvest at the maker's cue, before caps flatten, if spores near a bed would be a problem. Misting and the signs that should make you stop are in how to use a mushroom grow kit.

Which of these listings belongs indoors?

Carbeth is the straightforward indoor answer. It names shiitake, is sold as a kit and supports indoor growing. Read the windowsill line with the light and heat limits above. The small mixed review file means a crop is not assured. The rye-and-CVG bag gives no clear indoor claim and leaves out the culture. The dung-lover bag names no species and has one rating without written evidence. Neither is a sensible first indoor kit. The £7.49 chicken-of-the-woods culture is the clearest conflict. An attribute says indoor, yet the description points to oak and other deciduous trunks. A 65 cm field is not a shelf crop. Read mushroom kit versus liquid culture before you treat the syringe as the cheaper indoor option. Do not eat coloured mould. Cook the crop you intended to grow.

Common questions

Can I grow mushrooms in a flat with no garden?
Yes, a named ready culinary kit can fruit in a flat when it has indirect light, suitable species-specific conditions and moisture without standing water. You do not need a greenhouse. A liquid culture or an uninoculated substrate bag is different and needs more than a suitable room.
Is a kitchen windowsill a good place?
Only if it stays shaded, stable and away from a radiator. Carbeth names a windowsill, but other UK makers warn that direct sun and night-time temperature swings can dry or stress a block. A nearby shelf with indirect light is often easier to manage.
What temperature should the room be?
Use the range in your kit's instructions. Other UK makers quote ranges such as 14–21°C or roughly 15–24°C for their own gourmet kits, but those figures are not a Carbeth specification. Avoid rapid swings, a working radiator and heat from cooking appliances.
Do mushroom kits need darkness?
No. They do not photosynthesise like plants, but many gourmet kits use indirect daylight as a growth cue. Choose a bright, ventilated room without direct sun rather than a sealed dark cupboard, unless your kit's own instructions require a particular enclosure.
Is a bathroom better than a utility room?
Neither room wins by name. A bathroom may be humid but can lack light or contain aerosol cleaners. A utility room may be stable until a dryer heats it. Choose the room that offers indirect light, ventilation and the smallest daily temperature swing.
Can chicken-of-the-woods liquid culture grow on an indoor shelf?
The available listing does not establish that. Although an attribute says indoor, the description refers to oak and other deciduous trunks and includes no block or log. Treat it as one component of a hardwood project, not a self-contained windowsill kit.

Related pages

Best mushroom kits in this set

Mushroom culture

Mushroom growing kit UK: choose the right product type

How to use a mushroom grow kit: open, mist, harvest

Mushroom kit vs liquid culture: which should you buy

Sources

Sources checked for this comparison; last retrieved on 16 October 2026.

  1. GOV.UK, drugs penalties (retrieved 16 October 2026)
  2. Drugs Act 2005, section 21 (retrieved 16 October 2026)
  3. Misuse of Drugs Regulations 2001, regulation 4A (retrieved 16 October 2026)
  4. Woodland Trust, chicken of the woods (retrieved 16 October 2026)
  5. Kew Grow Wild, chicken of the woods (retrieved 16 October 2026)
  6. Food Standards Scotland and the FSA, listeria in imported enoki (retrieved 16 October 2026)
  7. Merryhill Mushrooms, contamination on a growing kit (retrieved 16 October 2026)
  8. amazon.co.uk listings for the four products (retrieved 16 October 2026)