Collection: Propagators & Humidity Domes

Hydroponic propagators and humidity domes are the first piece of equipment that determines how well a grow season starts. Whether you're germinating seeds into Rockwool cubes, striking cuttings in coco plugs, or running an aeroponic cloner, the enclosed microclimate created by a propagator — warm substrate temperature, high ambient humidity, and protection from air movement — is the difference between a reliable strike rate and patchy, inconsistent results.

Why propagation environment matters

Seeds and unrooted cuttings have no root system to draw water from the growing medium. They rely entirely on foliar moisture absorption and substrate warmth to stay turgid and trigger root initiation. A humidity dome maintains relative humidity of 85–95% around the cutting — high enough to prevent wilting while roots develop, but with enough air exchange (via adjustable vents) to discourage mould. Substrate temperature is equally important: most cultivars root fastest at 22–28°C at the root zone, which is why a dedicated heat mat or heated propagator outperforms a humidity dome placed in an unheated room, particularly during Australian winters.

What's in this collection

• Vented humidity domes — rigid clear covers designed to fit standard propagation trays, with adjustable vent panels to regulate air exchange and prevent excess moisture build-up
• Humidity domes & propagation kits — self-contained enclosed units for compact clone batches; suited to Rockwool cubes, Jiffy pellets, and coco propagation plugs

How to choose

Heat mat + dome vs. heated propagator

A separate heat mat and dome gives more flexibility — you can size the mat to the tray and replace components independently. A heated propagator is a simpler single-unit solution, better suited to growers who want a plug-and-go setup or who are working with smaller clone numbers. For larger production runs, multiple heat mats under standard 1020 trays with tall domes is the more scalable approach.

New to propagation?

Start with a heat mat, a clear vented dome, and a pack of Rockwool cubes or Jiffy pellets. Add a rooting gel or cloning powder from the Seed & Clone Care collection to improve strike rates. A propagation grow light positioned 30–40cm above the dome completes the setup and significantly improves seedling quality before transplant.

Humidity and venting

Open the dome vents slightly from day three to four of cloning to begin hardening cuttings to ambient humidity. Fully sealed domes with no air exchange increase the risk of botrytis (grey mould) in warm conditions — particularly relevant in Australian summers where grow room temperatures can spike.

A-Grade Hydroponics stocks propagators and humidity domes suited to hobby home growers through to larger production operations, with Australian stock and expert advice available by phone or live chat from our Cheltenham, VIC store.