Here are the basic steps I use with almost all seeds.
- I use the 36 per tray plastic cells in a 1020 tray. Usually available at nurseries. Also get the clear tops. I find that the 72 size cells are too small to get good root growth.
- I cut out one cell so that I am left with 35 cells. I water from the bottom through that hole.
- I put this 1020 tray in a heavy-duty plastic tray. I buy those from Burpee.com. It prvents leaks. The 1020 trays are usually made of cheap plastic.
- I use my preferred potting mix as a base – BX Pro-Mix with some Osmocote. You can find this at either a nursery, Walmart or Menards and some smaller hardware stores. Any Pro-Mix product should be fine.
- Make sure the mix is well watered before you add the seeds.
- I put 1 to 3 seeds on top of the mix. It depends on how expensive the seeds are and how many I have.
- I top the seeds with a light layer of vermiculite.
- I spray the vermiculite with water.
- I label each cell with the date, seed name and number of seeds. I use vinyl blinds that I have taken down. These are easy to cut and label with a pencil.
- I also put in about 1/8 inch of water in the bottom of the tray in case the mix needs to absorb some water.
- I cover the tray with a plastic clear top.
- I lower my Lithonia T8 shop lights to within 1/2 inch of the plastic top.
- I keep the lights on 24/7 to keep it warm.
- When the seeds are well germinated, I take off the clear top.
- I also use a rotating fan on the seedlings.
Most of the seeds I grow need about a soil temperature of 70 degrees. That’s what Shaw Nature Reserve uses and what has worked well for me in the past.
Note – I used a Laser Infrared Thermometer to get the soil temperature.
In the past I have used heating mats to achieve this temperature, but I noticed a difference this year since I have started using different lights.
I now use and recommend, Lithonia Lighting, 4-Light Grey Fluorescent Heavy-Duty Shop Light. They use T8 bulbs. I now uses these bulbs close to the seed trays with a plastic cover. LED light bulbs have 1800 lumens/bulb. The traditional T8 bulbs put out 2600 lumens/bulb. I prefer the traditional bulbs because they put out more light.
As you can see from the picture, there isn’t much difference between trays with or without bottom heat. In fact the bottom heat tray seems to have poorer germination. I did notice that the bottom heat trays got up to 97 degrees while the trays with just the 4 bulb lights got up to 77 degrees. I eventually turned off the bottom heat since it seemed to be to high.
I probably won’t use my heating mats in the future since my new lights put out enough heat to get seeds to germinate.