Florists' Green Waste Blooms into Something New

Last Tuesday I spent the morning in a compost heap, not necessarily on my bucket list for 2026 but fascinating nonetheless.

Along with some of their first ever florist customers, I was invited by Com-post to tour one of their commercial composting sites. Com-post are Hannah (florist) and Fiona (business dynamo) and they were one of the five finalists at the inaugural Sustainable Floristry Innovation Awards at the 2023 Interflora Word Cup. They had a simple but brilliant idea, and after piloting it in London they’re about to really scale it up.

Most green waste from florist shops ends up in landfill - think leaf strippings, stem trimmings and dead flowers. In landfill, this kind of organic matter doesn’t rot down harmlessly - due to the lack of oxygen present in landfill it creates dangerous, planetary-warming greenhouse gases (GHGs). The same goes for the fruit and veg peelings from your kitchen, once in landfill, organic waste is a GHG generating timebomb.

Bags of green waste awaiting decontamination

Com-post recognise this and have a passion for transforming the mountains of green waste in our industry into something with a force for good. They have created a beautifully simple closed-loop, easy to access composting system to manage floristry waste:

1. Paper bags are dropped at florist shop – huge, very strong, and fully compostable

2. Florist fills bags with green waste, which are collected by a composting company

3. Green waste (including bags) is transformed into compost through a 13-week natural process - no additives involved.

4. Finished compost goes back into farming and horticulture, closing the loop.

Com-post launched in 2024 in the London area and having gone from strength to strength are about to roll out across the country. I sincerely hope that as many florists as possible take advantage – the cost is comparable to standard green waste collections by local authorities, and the florists present on the tour (including Interflora member Sonning Flowers) couldn’t praise the Com-post service highly enough.

Turning the compost - you can see the steam coming off it!

So how do you make compost from florists’ green waste?

Step 1 Decontamination:

Green waste is manually checked for contaminates and cleansed. Plastic is a big no-no, as are thorn-strippers, scissors, gloves, and mugs (yes they've found mugs more than once!)

Step 2 Sanitisation:

Green waste is then shredded and becomes part of a windrow (long mound) of compost for 3 weeks at a temperature between 75C-90C to kill off weed seeds and pathogens; you can see the steam coming off these windrows During sanitisation, the compost is turned multiple times to maintain aerobic decomposition throughout the windrow.

Step 3 Stabilisation:

A further 8 weeks of managing the compost at around 55C. Temperature and moisture are closely monitored, and the compost is regularly turned, at least once a week. At the end of this step, the compost is screened to remove any uncomposted components, and graded into 10mm (garden compost) and 20mm (farming).

Step 4 Maturation:

Once graded, the compost is stored in stock piles for a further 2 weeks to mature before it is distributed to farmer’s fields across the country.

Simple as that. And yes, we did get to take a goody bag of compost home at the end of the visit.

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Zara Taylor is the Head of Wholesale & Supply at Interflora.

She has worked in flowers since 2010, first at Flamingo Horticulture, then at Interflora. Zara recently completed Cambridge University’s CISL course on Sustainable Business Management, and has a real personal passion for living a positive, minimal impact lifestyle.