KNOL: How to Start Seeds in Seed Trays Indoors (In Pictures)

Transfered here for storage from my Google Knol articles.

You can save a lot of money by starting your own vegetables, herbs, and flowers indoors in seed trays. The seed trays range from $3-$5 for a flat. The seed starting medium cost $4-$5 and is enough for 3 flats. The seeds cost $1-$3 a pack. It doesn't cost much to get started and you can re-use your seed trays and cells, year after year. Give it a try!

How to Start Vegetable Seeds in Seed Trays (In Pictures)

By Gary Pilarchik LCSW-C

 

 

Visit my blog for updated information about gardening: The Rusted Vegetable Garden

 

 

Seed Starting Indoors: The Supplies

Starting seeds indoors is easy, very easy. It will save you quite a bit of money and it allows you to germinate plants you might not find in your local area.

Seed Starting Mix

You need to buy seed starting mix. It is inexpensive. It is sterile.  I bought a bag made by Miracle Grow. You can see the packages states exactly what your need: seed starting potting mix. I think the cost for the mix was $4.99

 

You can make it yourself if you choose. If you make it yourself you should follow 1 part peat moss: 1 part vermiculite: 1 part perlite. You can exclude 1 of the latter two. You would also need to put lime in the mix to manage the ph of the peat moss. I used to make it. Now I just buy it on sale. It is much easier to buy it. 

 

Seed Starting Tray and Cells

You also need a seed starting tray. You can buy one set. A set inlcudes the black flat tray, the 72 cell insert that goes in the tray, and a clear plastic tray top. I don't use the plastic top. My tray is sitting in the plastic top, in the picture below.  I buy my tray sets in a package of 3 and a 3 package set costs about $8 at Loews.

 

Fill the Seed Cells with Starting Mix

Fill the tray with seed starting mix. And this is important, pack each cell of mix down with your thumb and refill. You want to make sure the mix is nicely packed in each cell. I you don't, your seeds can drop to the bottom. I prefer to have a lot of seed starting mix in each cell because I over plant my cells. If this is your first time planting in cells, only put 1-3 seeds per cell and follow the package instructions.

 

Seed Starting Indoors: Buy the Seeds You Want to Grow

Next pick out what you want grow. If you read the back of the seeds it tells you when to plant them indoors. It will also tell you if you can plant them in seed trays. Radishes for instance should always be planted straight in the garden. For instance, tomato packs will tell you to start the seed indoors 6-8 weeks before the last frost date in your area. I live in Maryland which is zone 7. Zone 7 means I can typically plant tomatoes outdoors May 1st. Using that date, I would start my tomatoes and other seeds that need 6-8 weeks to grow between March 1st and March 15th. If you do an internet search for gardening zones, you can find your area.

 

Why Did I Pick Lettuces and Basil?

Greens are cool weather crops and they grow quickly. Cool weather crops can go in the garden and handle cold nights. They can even handle some frost. Lettuce, Kale, and Collards are cool weather crops. I grow them in indoor, and transplant them directly to the garden in late March, and in April.

 

Basil, is colored green but it is not a cool weather crop. In needs heat. It is an herb and all herbs can be started indoors quite early. Basil is expensive to buy as a transplant. Using this method, 1 pack of seed will easily plant 18 cells. Basil cost about $2 - $4 a plant if you buy them at a nursery. For $2.00 you can get 18 plants. That is quite a bit of savings.

 

 

Starting Seeds Indoors: How Deep Do I Plant the Seeds?

You can follow the instructions exactly as the pack states for planting depth. I find you can plant most seeds 1/4 inch down. You don't need to stress over the difference between 1/8 and 1/4. They grow. The only ones you don't want to bury are seeds that have instructions to press them on the surface or lightly cover.

 

I am mixing three packs of large sweet green leaf basil together and putting (yes) 10+ seeds in each cell.  Why? They will grow just fine and like water. If I keep the cells moist, the basil and lettuce will grow well. Once the plants are large enough, I divide them up. Lettuce and basil are easy to divide. You can gently break the clumps of starting soil apart and divide them 1 plant at a time if you want. Not all plants  divide that easily. If you enlarge the photo, you can see the cells are over planted with seeds. Remember nature doesn't drop seeds one inch apart. Those are basil seeds in my hand. The seed packs will tell you the recommended number of seeds to plant.

 

 

It is hard to tell put you can see 5 lettuce seeds scattered on the cells below.  Again, the seed pack will tell you how many to plant. From experience I know I can easily divide lettuce. I put in 5 or more seeds.

 

Once the seeds are in on the soil, I use a popsicle stick to mix them down to about 1/4 of an inch and then press the soil down with my thumb. This ensures good soil to seed contact for germination.

Each group of 9 cells gets labelled with a stick. Below I planted foxglove. Flower seeds can be started indoors too. In my hand there is probably 500 seeds. They all wont germinate. But they will be planted heavily in the cells. I just break them into bunches when I transplant them into cups. I break them again when the get bigger. And then 1 more time before they go into the ground. Foxglove is lightly covered with soil. Just drop a little mix on them and press it down with your thumb. This process works for foxglove, in the case of flowers, follow the seed pack directions.

 

Starting Seeds Indoors: Watering

Never water from the top. Never... no never. Don't do it. It is too labor intensive. It will wash mix and seeds out of the cell and it will cause damping off, a fungus disease. Water from the bottom. Fill the tray up nearly halfway with warm water. Make sure the tray is on a level surface. In about 2-3 hours your starting mix will  absorb the water. You are good to go on watering now for 7 days. When the cells look dry...fill from the bottom. Dump out excess water if you get carried away. At this point you can put the clear plastic dome on your plants. Only keep it on until the seeds germinate and then remove it. Too much humidity can cause disease.

 

Starting Seeds Indoors: Warmth and Light

 

You seeds need to sit around 65 degrees or more. Typically a house regulates that temperature for you. If you are growing them in a basement or garage, you may need to purchase a seed heating mat.

 

Light is a bigger issue then temperature. I use growing lights. You can see them below. If you want to use growing lights, you can read about setting them up at my blog or on the internet. The seed trays should go to a south facing window. This is the window that gets full afternoon sun. Your plants can make it on 6 hours of direct light but they might get leggy. That means the are growing extra tall to find light. If you can find a window that gets 8 hours of light or more, you plants will grow more as the were meant to be: stocky, firm, and leafy. You can always move them from window to window if you have the time.

 

Starting seeds indoors is really easy. Give it a try. I do use a growing station. The light stay on 12 hours.

Here are some pictures of seeds I started about a month ago.