Grow-a-long Seed Starting Part 1

Seed starting may seem like a daunting task but it’s actually really easy. All you really need to do is understand the fundamentals of seed starting, then be there for your seeds and seedlings to give them the little bit of attention that they need everyday.

Early seed starting should be thought about in two stages: Germination and early growth. This post will mostly focus on planting and the germination stage. In order to germinate, the most important things for most seeds to have are Moisture and Warmth. Some seeds need light to germinate, which we will provide with our grow lights. Another important factor that’s related to light and moisture, is following the recommended seed planting depth, which is always listed on the back of every seed packet. If you can’t find that info, a good rule of thumb is a depth twice the size of the seed.

My efforts in this post will be dedicated towards creating the optimal environment for your seeds to germinate and grow their first set of leaves, called cotyledons.

All The Gear You’ll Need for Seed Starting

Before getting started it’s best that I share the full list of seed starting gear. I also just published A YEAR OF GARDEN GEAR which includes all of these products plus a ton more, so if you’re the type that likes to get everything checked off, you can review the list and see what’s still outstanding. The gear you will need are:

Lighting and Grow Room Setup

As soon as you receive this gear, it would be wise to setup right away. That way it’s waiting and ready on the day you start your seeds, which should be quickly approaching.

  • Grow lights – Mine are 4 feet long. These 2 ft versions are recommended for first timers. Two 2 ft shop lights spaced about 6-8 inches apart will make a perfect growing area for the purposes of this Grow-a-long, about 2ft x 1ft. If looking to make a slightly larger grow space, a 2×2 area would use 3-4 2 ft shop lights spaced about 5 inches.
  • Light Stand – This is a smaller version of the rack I’m using, while this option will work great too.
  • Light Mounting System – This simple and cheap DIY option just requires a drill.
  • Light Hangers – Light height needs to easily adjusted and these are super simple.
  • Heat Mat – This mat and thermostat raise soil temps to speed germination times and early plant development
  • Electric Outlet Timer – This is an indispensable tool for any grow light setup. It has one set of strips controlled by a timer and another set that are always on.
  • Fan – Once our seedlings have germinated we will remove the humidity domes. At that point it’s advisable to have circulating air around the seedlings. This will keep mold and diseases down.
  • 1020 Trays – These trays are helpful for keeping your seed starting area tidy. They have a bunch of other applications in gardening so these are useful to have on hand.

Planting Gear

  • Seedling Trays – You can use a lot of different vessels for starting seeds. You’ll need roughly 30 seed starting cells for the whole Grow-a-long. It’s always best to have more space. That way you can start some extra flowers or other veggies. Here are a few recommendations for first timers:
    • For the sake of the Grow-a-long and to demonstrate how easy it is to start seeds, I’m starting seeds in an 18 count plastic egg crate. Just make sure to clean and sanitize before use.
    • I received these prototypes which are available for pre-order. Thanks to the modular system based around six packs of cells, you don’t have to prep one big tray all at once. Other benefits are a large bottom hole perfect for popping out seedlings ready for the garden and great for bottom watering. There are small slits on the side that help eliminate root circling allowing them to stay in these cells longer, which is nice to have if a cold front comes in right before planting outside. I already think they are the next great thing for small to medium scale home seed starters. If you can wait until February to receive, these would be my first pick for you.
    • Here’s another great option for sowing all your seeds into. The capillary mat wicks moisture from the water reservoir below, giving the proper amount of water.
    • I’m also using Orta’s Seed Starting Pot, my favorite, easy to use system.
  • Spoon or small trowel
  • Tub Trug or Bucket – For mixing soil
  • Seed Starting Soil – Make sure not to substitute for other types of garden soil
  • Watering Can
  • Small bowls or plates – For pouring seeds into to speed up seeding
  • Dibber – I used a wood skewer, marked in increments of 1/4″. The skewer is also great for picking up small seeds.
  • Plant Labels – Make sure to label your plants and mark the date sewn
  • Humidity Dome – If possible, use what you have already. I’ve successfully used lettuce plastic packaging and reusable foot containers as humidity domes.

This Week’s Seeds

We will be starting all of the seeds that were in the 8-10 Weeks before Last Spring frost. Here’s the list and the minimum number of cells to sow:

  • Kale – Dazzling Blue – 4
  • Lettuce – Flashy Butter Gem – 4
  • Fennel – Florence – 4
  • Eggplant – Melanzane Rosso Di Rotonda OR Antigua- 1
  • Pepper – Shishito – 1
  • Tomato – Chadwick Cherry – 1

Step by Step Guide for sewing seeds

  1. Assemble all of your Planting Gear in a large enough area to work comfortably. I like to pour seeds for each variety onto a separate plate, saucer or bowl so I can quickly grab seeds.
  2. Moisten your seed starting soil in a bucket. Mixing it thoroughly. The soil should be roughly the moisture level of a wrung sponge, not soggy but not dry.
  3. Fill the cells of your seedling trays. If using a larger seed tray such as a 72 cell tray, you can leave a portion of the tray without soil and fill it in with later sowings.
  4. Give a light press down of the soil in the cells. Ideally we want them completely full without spilling over. Wipe away excess soil or top up if a few cells need more soil.
  5. Read the seed packets for proper seed depth. Use a dibber or DIY version to make 2-3 small holes evenly spaced in each cell.
  6. Sow 1 seed in each small hole, aka 2-3 seeds per seed starting cell. We do this to basically guarantee that we will have success and not have empty cells. In a few weeks we will identify the strongest seedling and cut down the others in the cell. It’s a painful process but a necessary one (we will revisit this in the coming weeks.) Lightly cover the seeds back up with the existing soil.
  7. Label each plant or create a legend of the whole tray. Make sure to always add the sowing date on the plant label.
  8. Mist or lightly water if you notice the soil is dry. Now you’re ready to put under your grow lights.

Step by Step Guide to Setting up the Seed Starting Grow Room

  1. Fully assemble your rack and grow lights.
  2. Setup automatic outlet timer. Connect lights. Set the timer to be on for 14-16 hours per day. I set mine on from 5am to 9pm, so that I don’t wake up the neighbors. Never keep the lights on 24/7 as seeds and seedlings need a resting period everyday, too.
  3. Plug in heat mat thermostat into the “Always on” side of the outlet timer and connect the heat mat. I’m setting my desired soil temp at 80F.
  4. Place your newly seeded trays on the heat mat and stick the soil temperature probe into an empty cell of soil if you have any. If there are no empty cells, stick the probe into the side of one of the Kale or Lettuce or Fennel cells. Since we are growing multiples of these plants, if we end up losing one because of the soil probe, it’s not the end of the world.
  5. Put on your humidity dome. You can also mist the inside of the humidity dome with water to up the humidity.
  6. Lower the lights to sit right above the humidity dome. Note – After germination it’s best to keep our lights 2-4 inches above the seedlings.

Since soil moisture is such an important factor for seeds and seedlings they should be watered at least daily. Again the optimal soil moisture is comparable to a wrung sponge. There are a few methods which I talk about in the video, but those can be categorized as top watering or bottom watering. For top watering, we don’t want to splash around a lot, so a seedling watering can, pump mister, plastic wash bottles or syringes can be very effective. Bottom watering is a tidy, effective and easy way of getting plants enough moisture. To bottom water, simply place your tray in a larger flat tray with water and let it soak up moisture through the drainage holes. 10-15 minutes is recommended here.

What you’ll start to see

After about 5-7 days you should start to see some signs of life from your seedlings. Look for little pops of green. After about 75% of seed cells germinate, maybe around 10 days after sowing, it’s time to do two things. The first, is to remove the humidity dome. The second, is to roughly assess your germination success. It’s always a great sign if all 2-3 seeds germinate in each cell, but if you see nothing in the cells, look for signs for what could be going wrong. Are the temperatures of your soil in the 70-80 range or are they much colder? Did other cells of the same variety germinate? Maybe it’s just a cell related issue such as not enough or too much watering. Either way, give it up to 14 days after sowing to germinate, you can always try it again if it doesn’t sprout up.

Other Notes about seed starting

  • You’ll notice that you are going to have a lot of extra seeds. Unfortunately, there’s not a way to get just the right amount of seeds that you use. Counting down to the individual seed is just too labor intensive for seed companies. The good news is that you can save many of them with the same viability for 5 years. Make sure to store them in a cool, dark and dry place. Another option is to share them with friends or if you have space, start extra seedlings and then give those away or find a spot to tuck them in your garden.
  • It’s important you follow my advice to only sow 2-3 seeds per cell. While you can technically germinate dozens of seeds per cell you will quickly run out of room. In the coming weeks you’ll be asked to snip all but one of the seedlings in each cell. This process is always painful for the first time seed starters and I’ve found the more seeds you start, the harder it is to say goodbye to all the plants that could have been. If you do decide to prick the extras out and reuse them, untying the roots of 2-3 seedlings is way easier than 5-10.

9 thoughts on “Grow-a-long Seed Starting Part 1”

  1. Thanks for posting and very clear! Do you have any recommendations for indoor watering if out of town during this process? I’ve seen some things on Amazon but wasn’t sure if you have used anything.

    1. I had a feeling this would come up. There’s not a fantastic solution that I know of, though I have a DIY solution in mind. If you want to do some extra research, lookup Ebb and Flow watering systems. You’ll have to setup a submersible pump. The Orta’s Seed Pots are maybe the best bet as the water reservoir lasts for about a week and probably longer with a humidity dome. I normally have a family member come by every two days to water so I haven’t had to figure out a long term automated system.

      1. Looked that up and gave me an idea. We have a boiler that pumps water from the condensation overfill into the floor drain. I could redirect the hose into a basin that the trays are in. But that would basically have it soaking all the time. Assuming that is not ideal and would result in too much water. Thoughts?

  2. Hey Tom, what are your thoughts on the self-watering aspect of the GrowEase Seed Starter Kit from Gardener’s Supply? Personally, I had a hard time keeping the water distribution balanced. I found it more efficient to remove the seed tray and water the mat myself rather than pouring water in the reservoir as the instructions suggested. Was wondering if you had the same experience. Thanks!

    1. Ya, at times it did get too wet. A better system would wick water from both sides of the tray. Though if I do compare it to other methods of seed starting everything I started using that were very successful.

  3. Hi Tom! Thank you so much for this guide. This is really what I needed last year, when I trying to figure everything out for the first time! I’m excited to try again under your guidance.

    I’m wondering about a good substitute for dill, because I don’t love to eat it. Is there another herb you think would be a good choice in the garden? Thanks!!

  4. Hi Tom,
    I’m starting Lace Flower indoors as well, and the packet says to start 8-10 weeks before last spring frost. My question is with close to 100 seeds per packet, should I start the entire packet? Or only do a few cells as we are with the lettuce?

    1. Hey there, it depends on how many total plants you want. I doubt you would want 100 plants. I typically sow about 3 seeds per cell. I sowed something like 12 cells of Queen Anne’s Lace so I’ll have 12 total plants.

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