Building a VIVOSUN Propagation Setup
A complete
VIVOSUN propagation setup is three components working together: a heat mat under the tray (substrate warmth), a 1020 nursery tray (water reservoir and root structure), and a humidity dome on top (humidity and air retention). Each component scales with seedling count.
Propagation Sizing
When to Use a Humidity Dome
Use the dome from seed pop through the first true-leaf stage (typically days 0-10 for vegetables and herbs, days 0-7 for cannabis). The dome holds 80-95 percent RH at the tray surface, which prevents the cotyledons from drying out before the seedling can establish a working root system. Remove the dome gradually after day 7: prop one corner open for 2-3 days to acclimate the seedlings to ambient room humidity, then remove fully. Leaving the dome on too long causes damping-off (fungal stem rot at the soil line). For clones, keep the dome on 7-14 days until roots are visible at the bottom of the cube.
For light setup once seeds sprout, see
light colors for strong seedling growth.
Related Guides
The heat mat side of propagation is covered in detail at
VIVOSUN seedling heat mats. Cross-brand propagation gear lives in the broader
propagation lineup.
Frequently Asked Questions
What temperature do seeds need to germinate?
75-85 degrees F at the substrate level for most warm-season vegetables, herbs, and cannabis. Cool-season crops (lettuce, spinach, brassicas) germinate at 60-70 F. Lower temperatures slow germination by 50-70 percent; higher temperatures kill viability. The substrate temperature matters more than the air temperature; a heat mat is the reliable way to hold it.
Do I need a humidity dome for clones?
Yes, clones need the dome for the first 7-14 days. Without a root system, the clone can't replace water lost through the leaves; high humidity slows leaf transpiration so the clone has time to root. Remove the dome gradually starting around day 7 once you see new growth or roots at the cube bottom.
When do I remove the dome?
Start removing after the first true leaves appear (day 7-10 for most seedlings). Prop one corner open 2 inches for 2 days, then 4 inches for 2 days, then remove fully. The gradual acclimation prevents transplant shock from sudden humidity drop. Leaving the dome on past true-leaf stage encourages damping-off fungus, which kills seedlings at the stem.
Can I propagate without a heat mat?
Yes if your room stays above 72 F continuously, but the heat mat is worth it. Without a heat mat, room temperature swings 5-10 F day to night, which spreads germination across 5-7 days instead of 2-3. The mat speeds and tightens germination timing, which matters for crop scheduling and clone batch uniformity.
How long does propagation last?
Seedlings stay in the propagation tray 14-21 days from sowing to first transplant. Clones stay in the tray 10-14 days from cutting to roots-out-the-bottom. After that, transplant into 1-gallon nursery pots and move to the main grow tent under appropriate light intensity.
Does VIVOSUN make a complete propagation kit?
VIVOSUN sells heat mat plus thermostat bundles that cover the temperature side; the tray and dome ship separately. Building the complete setup from parts (heat mat with thermostat, 1020 tray, 6 inch tall humidity dome) gives more flexibility than a fixed kit because you can size each component to your specific seedling count.
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