- Temperature and humidity are important. Improve success rate by using a heat mat or putting in a very warm place until the seeds have sprouted. Most plants have optimal germination temps between 75-90 degrees. Use a thermostat to dial back the heat or put a piece of cardboard between the tray and mat once they have sprouted.
Keep relative humidity at 95%. Using a humidity dome and putting about a 1/4" of water in the bottom of the propagation tray will help.
Once sprouted, seedlings have enough nutrition biologically to get them to their second set of leaves. They don't need a lot of light for the first 2 weeks. One 18 watt T5 fluorescent fixture is plenty to use until transplanting.
For really strong roots, moisten the plugs using a mild kelp solution, or for high value plants add a product like House and Garden Root Excelleurator. Mycorrhizae is also a commonly used beneficial fungus to use after roots have developed.
Slowly introduce them to the outside environment by cracking the vents on the dome little by little over a few days. Give them a day or two after taking off the dome before transplanting to a larger container.
**Bonus For hard-sided seeds use an emory board in a medicine bottle to score the outsides, then soak them for 8-24 hours in a wet paper towel before gently transferring to the plugs.
Hope you enjoyed the post=). What kind of tips or tricks do you use for a high germination rate?