Propagators

A propagator is a tray, a humidity dome and – on the ones worth buying – a heat source. It creates the warm, saturated pocket of air that seeds and cuttings need for the first two weeks, when they cannot regulate themselves.

Heated or unheated?

Heated, if you are taking cuttings. Root formation is driven by temperature at the base, not by light or nutrient, and a room at 18°C gives you a tray at 18°C. Cuttings root at 21-24°C. An unheated propagator is fine for seeds germinating in a warm room and not much else.

What to look for

• Adjustable vents in the lid. Non-negotiable. You start sealed and gradually open them over a week to harden the plants off. A dome with no vents means opening the whole lid, which shocks everything in the tray.
• Dome height. Low domes for cuttings, tall domes if you are germinating seeds that will stretch before you pot on.
• A thermostat on heated models. Without one you are guessing, and an overheated tray cooks cuttings faster than a cold one kills them.
• Tray strength. Cheap trays flex when full and dump water. Worth paying for.

Aeroponic propagators

The step up. Cuttings sit in neoprene collars over a misting chamber with no medium at all – roots get maximum oxygen and typically appear several days sooner. Higher success rate, more to go wrong, and they need cleaning between runs. Worth it if you are propagating regularly.

Running one properly

1. Seal the vents for the first two to three days while cuttings have no roots.
2. Open them progressively over the following week as roots form.
3. Keep the base at 21-24°C and the room cooler than the dome.
4. Low light only – see propagation grow lights.
5. Wipe condensation off the lid daily. Drips onto leaves cause rot.

What we stock

Garland heated and unheated propagators, X-Stream aeroponic propagators, Garden HighPro Probox units, heat mats, thermostats and replacement domes. Pair with propagation media and cloning products, or step up to a propagation tent for a bigger run.

Why buy a propagator from The Hydro Bros?

We are a hydroponics shop in Croydon and we run these daily. Tell us how many cuttings you take at a time and we will spec the tray rather than sell you the biggest one. Discreet UK and European delivery, and excellent customer reviews on Trustpilot.