Firmness
Medium
Type
Pocket Spring
Depth (cm)
31
Number of Layers
4
Trial Period (nights)
60
Warranty (years)
5
Price Range
£645 to £935
Best Sleeping Position(s)
Certifications
Assessed from Silentnight's published specification for this mattress, captured September 2026, and from regular price comparison across our UK retail partners.
This mattress makes sense if you want natural materials without giving up spring support. The comfort layers use bamboo, kapok, flax and aloe vera, sustainably sourced according to Silentnight, sitting above 800 Mirapocket springs paired with 1000 mini springs. That combination means the springs move independently under you, so a restless partner is less likely to disturb your side of the bed. The Tencel Lyocell sleep surface is woven to allow airflow and move moisture away, a genuine plus if you tend to run warm at night. The 60-night trial gives you a proper chance to test it at home, and delivery is quoted at 14 days. It is not the cheapest option, but the materials help justify the price.
Key Features & what's inside
- Tencel™ Lyocell sleep surface. A silky, soft touch top layer woven to allow airflow and carry moisture away from you as you sleep. In practice, that means a cooler, drier feel through the night.
- Platinum comfort layer. Silentnight says this layer is ten times more breathable than memory foam while offering the same pressure relief. You get that cocooning, contouring feel with less of the heat build-up memory foam is known for.
- Plant Based Comfort Layer. A cushioning layer made from a combination of bamboo, kapok, flax and aloe vera, which Silentnight says is sustainably sourced. This is where the mattress gets its plant based name and much of its soft, breathable character.
- Mirapocket® springs and mini springs. 800 Mirapocket springs adjust to your movements through the night, combined with 1000 mini springs for extra comfort and breathability. Each spring works independently, which means better isolation of movement between you and a partner.
Layer details from silentnight.co.uk product page, September 2026.
Who's it NOT for?
If you prefer a firm mattress, this medium tension with a plush box top will likely feel too soft, particularly for heavier back and front sleepers who need a flatter surface. The 31cm depth may also cause problems with shallow fitted sheets, so check your bedding before you buy.
Silentnight Plant Based Box Top 1800 Mattress
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Is the Silentnight Plant Based Box Top 1800 foam free?
According to Silentnight's product page, yes. The mattress is described as foam free and uses natural flame retardants. Its comfort comes from plant based materials, bamboo, kapok, flax and aloe vera, along with a Tencel Lyocell sleep surface, rather than synthetic foams.
How firm is the Silentnight Plant Based Box Top 1800?
Silentnight rates it as medium. That tension suits most back and side sleepers, offering a balance of cushioning and support, although lightweight side sleepers may sink in a little less than they would like, and those wanting a firm feel should look elsewhere.
Does the Silentnight Plant Based Box Top 1800 come with a trial?
Yes. Silentnight offers a 60-night trial, so you can sleep on it at home and return it if it does not suit you. It also comes with a 5-year guarantee, and delivery is quoted at 14 days.
How many springs does the Silentnight Plant Based Box Top 1800 have?
It contains 1800 springs in total: 800 Mirapocket springs that adjust to your movements, plus 1000 mini springs for additional comfort and breathability. Because each pocket spring moves independently, you should feel less disturbance from a partner shifting position.
How deep is the Silentnight Plant Based Box Top 1800?
It is 31cm deep, which is on the taller side thanks to the box top construction. Standard fitted sheets may struggle to cover it fully, so deep fitted sheets are a sensible buy alongside this mattress.
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