Successfully Growing Seeds Indoors under Lights

Have you ever thought of starting plants from seed like tomatoes, cucumbers, herbs, flowers, and peppers but thought it might be too hard or you would be killing them before they even get started? Many of the plants you purchase at the nurseries are the same varieties. Starting seeds indoors allows you to grow a wider variety of vegetables, flowers and herbs you would not normally see at the nursery. The bonus…it will save you a lot of money as can grow many plants from one pack of seeds for $ 1.89.

Ideal time to Start Seeds Indoors

Know the date in your area regarding the last possible frost date for both spring and fall plantings before you plant outside. I usually wait an extra week just to be sure or use a floating row cover to protect the plants from frost just in case!
For example, if takes eight weeks to grow your seed to a seedling (check your seed pack), you would plant your tomatoes outside after the last frost date has passed. For example, if the last frost dates in my area (Kitchener) is May 15th, than I would need to start my seeds indoors on March 15th.

Use with Sterile Seed Starting Mix

Start with using a sterile seed starting mix or a soilless mix. Make sure the package says sterile on the bag, this will avoid potential disease spores right from the get go and will also avoid damping off later.

Soak Seeds before Planting

Some seeds will germinate faster if you soak them in warm (not hot) water for no longer than 24 hours. This would apply to hard-coated seeds like beets, chard and okra. Tomatoes, eggplant and peppers would normally not need pre-soaking prior to planting. I have tried soaking them in Epsom salts for a 3-4 hours and for me this helps speed up germination by a couple of days.

Easy steps to Seed planting

  1. You can fill a flat of plugs/cell or egg carton with the sterile starting soil- ensure the soil is premixed with water so the soil is moist not wet. You don’t have to spend a lot of money on containers. Make sure you put a hole in the bottom as draining is very critical.
  2. Place the seed in the proper depth as per directions on the seed package and cover with a light sprinkling of medium (soilless medium) covering them completely.
  3. Place your flat or carton on a sunny window or purchase an inexpensive heating mat (under $20.00). This has worked really well for me as they can speed up the germination of all seeds. This also works very well for fruit bearing vegetables as most seeds prefer warm soil. Optimum germination temperature is between is 22-24 degrees C.
  4. If you don’t have a sunny window you can either cover with layer of plastic or purchase a plastic cover (to keep in the moisture of the soil) which can be purchased at any nursery or Home Hardware for a couple of bucks. The key with the plastic cover is you can use them year after year.

Lighting options

There are three options you can use for lighting: windows, fluorescents or LED Lights.
The ideal scenario would be to have a south facing window with at least 8 hours of day of sunlight. Note you will have to rotate the flats as the seedlings will become long and lanky.

For me, once the seedlings have emerged from the containers I would either use fluorescents or LED lights. My flats are in our basement which is very dark with the only light in the room coming from the LED lights. The lights are set at least 2-3”inches away from the plants to encourage steady growth above and below the soil. Your lights should be on 12-16 hours a day. Once the seedling has its first set of leaves, you can remove the heat pad as its purpose of germination is now complete. Ensure the seed trays are kept well-watered which is very important at this stage. I would also purchase a small fan to place near the seedlings to keep the air moving. This will help prevent damping-off disease. This will ensure good air movement and keep the surface of the soil dry. The goal is to create a gentle breeze; don’t point the fan directly at your seedlings and keep the fan running 24 hours a day if possible, a minimum of 8-12 hours.

For myself, I use LED Lights and have had great success over the last 7 years with them. The other key benefit is LED lights use much less energy than fluorescents. They also last much longer and are nontoxic to the environment. The down side of using fluorescents is they contain mercury and wind up polluting our land fill sites.

Hardening off

You have almost reached the final stage for growing successful seedlings…Congratulations! If you have planted your plants in small flats you may want to transplant to larger containers for better development of both roots and larger plants. This process will give you bigger, stronger plants and will give you a very high success rate of transplanting your seedlings into your garden.

To ease the transition from inside to outdoor (sunlight) planting, we need to ”Harden Off” the plants. This process involves progressive, incremental exposure of young plants to sunlight and outside weather. The sunlight will help the plant to acclimatize to the growing conditions of the garden and make them strong, sturdy and productive

I like to move the seedlings outside approximately two weeks prior to planting them in the garden. I like to start them in a semi shade area, then moving them to the full sun by the fourth or fifth day. If possible, start putting the plants out in full sun for one hour a day, then two hours the next day and so on until you reach a full day.
It is very important that after each sun interval, you remember to put the plants back into the shade until the plants are able to withstand a full days’ worth of sun. At this point you can leave them outside overnight providing there is no risk of frost.
So there you have it, the low down of planting seeds under the lights. The process is not difficult!

I have made mistakes in the past but have learned a lot by reading books and through trial and error. This is the process that has proven to work for me. I wish you much success!
If I can assist with any questions, you can send them through the website under “Gardening Questions”.

Happy Gardening 2019!

Submitted by Marty Schwende