What propagating sand is, and when to use it for cuttings

September 19, 2025

What propagating sand is, and when to use it

If you have put in a tray of seed or a row of cuttings and watched the lot of them yellow off, wilt or simply never come up, the odds are the problem was underneath them rather than anything you did afterwards. Most people start seed in whatever soil or potting mix is open in the shed, and for a lot of seed and nearly all cuttings, that is too heavy a start.

Why garden soil is the wrong place to start

Garden soil is built to hold water and feed established plants, which is exactly what you want in a bed and exactly what you do not want in a seed tray. It packs down when you water it, it stays wet in the middle, and a young root sitting in that has nowhere to go and nothing to breathe. Around here that is worse than average, because the soil is either clay that sets like a footpath or sand that dries out in an afternoon, and neither is a friendly place for something with no root system yet.

A cutting has it harder again. It has no roots at all, so it is sitting in wet media with a cut stem, and a cut stem in wet media rots.

What propagating sand actually is

It is not beach sand, and that matters. Beach sand carries salt and it is far too fine, so it packs down into something close to concrete. Propagating sand is a coarse grade sand, washed, with a grain size that leaves air spaces between the particles. Water runs through it rather than sitting in it, and the sand holds just enough moisture around the stem to keep it alive while it makes roots.

It also has almost nothing in it, and that is the point. There is no organic matter for fungi to work on, which is what keeps damping off and stem rot down.

The four jobs it is worth using it for

Seed trays. Use it straight or blended into a seed raising mix where you want more drainage than the mix gives on its own.
Cuttings. Rose, lavender and native cuttings go straight into damp coarse sand and root far more reliably than they will in potting mix.
Cactus, succulents and orchid back bulbs. All of them want sharp drainage and all of them sulk in anything that holds water.
Heavy clay beds. Working coarse sand through clay opens the structure up, which is a slow job but a permanent one.

A simple mix if you want to make your own

One part propagating sand to one part perlite or vermiculite gets you a light, free draining media that suits most cuttings. If the seedlings are going to sit in it for a while past germination, a very light scatter of slow release fertiliser is worth adding, because there is nothing in the sand for them to feed on.

Mix it until it feels crumbly and only just damp when you squeeze a handful. If it holds together in a solid ball you have either too much water in it or too much organic matter, and both of those are how you end up back where you started.

Is it worth the extra bag

For seed sown straight into a bed, no. For anything you are raising in a tray, and for every cutting you take, yes, because the cost of the sand is nothing against the cost of losing the whole batch and having to start again a month later. It is one of the cheaper things in the garden centre and it lasts a long time, since you only ever use a few handfuls at a go.

Shop related products

Brunnings Propagating Sand 5L. Coarse washed sand for cuttings, cactus and orchid back bulbs.
Brunnings Perlite 5L. Sterile and light, and it holds the air spaces open in a cutting mix.
Brunnings Vermiculite 5L. Similar job to perlite with more water holding, good in a seed tray.
Brunnings Seed Raising Mix 5L. Made for germinating vegetable, flower and herb seed and for leaf and stem cuttings.
Brunnings Premium Potting Mix 36L. Where the seedlings go once they have rooted and want feeding.

All of it is on the shelf in the garden centre, and there is more in the Brunnings range and the wider garden range online. If you are not sure whether your cuttings want sand or mix, bring me the plant name when you are in and we will work it out.

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What propagating sand is, and when to use it for cuttings