Seed starting: tiny seeds
This post shares our seed starting system. We are primarily using cell trays right now. So, this is not a post about soil blocking.
I’ve used soil blocking before. I found it to be more manageable on a smaller scale. As my business grew and we went from sowing hundreds of seeds per day to thousands, the small soil-blocking tools became more of a nuisance. There are some new soil-blocking tools on the market that are designed for larger-scale use. I’m looking forward to giving them a try. I’ll be sure to share our observations if people are interested.
Our current seeds starting method is centered on sowing seeds in 3 different size trays:
Large seeds (hyacinth bean vine) and seeds that grow quick tap roots (lupine and sweet peas, etc.) go into 50-cell deep root trainer trays.
Medium-sized seeds (like cosmos and zinnias) with predictable and strong germination go into 72-cell trays.
All other seeds are sown in row trays.
The row trays are the mainstay of our seed-sowing operation. I’ve tried many methods for starting small seeds. We’ve done the tedious “prick and plant” method with a toothpick or tweezers. We’ve used a nice vacuum seeder and the different-sized seeding trays that you must purchase for all the different seeds. We’ve tried tapping tools to drop seeds. We’ve even tried little vacuum-bulb-wand thing. There are a lot of tools for seed starting out there.
But we find that the row trays save us time, energy, and money. They are a simple solution to a number of seed-sowing problems we have encountered here.
Starting Seeds in Row Trays:
Fill your row tray with moist soil medium. Do not pack it in. Tap the tray on the table to help the soil gently settle in. It’s important for roots to be able to grow into the medium and a tightly packed soil medium is not helpful.
Set your row tray in a slotted 1020 heavy-duty base and a basket if you have one.
Use a pencil to dibbler tool to drag a small trench down the row.
Pour in your seeds. A 100-seed packet of small seeds can fit in just 1-2 rows. We do not meticulously count our seeds. We estimate. 100-seed packs are easy because they will often translate into about a 72-cell tray upon bumping up.
Cover the seeds that require cover and leave the ones that need light open.
Add a clear humidity dome and move them to your gemination area!
Benefits of Row Seed Starting:
Seed handling is easier. We’d prefer to handle small seedlings over tiny seeds we can barely see. We’re looking at you: snapdragons, poppies, eucalyptus, feverfew, strawflowers, etc!
Only those seeds that germinate are transplanted into larger cell trays, resulting in less wasted planting medium in those larger trays and less time lost filling cells that won’t germinate. When we sow directly into larger trays and some seeds fail, we have awkward blank spots in those trays.
Seeds germinate better (this is our finding anyways.) It is easier for us to look after these “critical-stage” seeds in fewer, more condensed trays than MANY larger cell trays.
Misting and watering take FAR LESS time. I’m thinking about all the hours we spend with spray bottles and misters— trying to keep our seeds hydrated. We can try to keep a few row trays on point OR we can try to keep dozens of larger trays going.
Row trays take up less space. We start our seeds on tables, shelves/heat mats. We can use less of the space and fewer lights with row trays because they hold SO MANY seeds.
After Germination:
Once your seeds have germinated you will remove them from the row trays. In most cases, the full row of seeds, roots, and soil lifts right out and can be pulled apart easily with your fingers. Break the seedling clumps into single plants or a couple of plants— whatever you prefer— and transplant them into larger cell trays. Leave any varieties that need more time to germinate in the row tray and return the domed tray to your seed starting area/racks to finish germination.
Final notes:
We take care to order the more sturdy versions of trays when possible and we try to always add a support basket to help our cell trays undergo less daily stress. We don’t love working with plastic trays, so we do our best to help them last a long time!
We use seed starting racks or tables in our basement for most of our seed starting. We can turn on some heat mats if we want to. We have also set up an inexpensive homemade germination station in our greenhouse to help warm our seed trays to about 70F while keeping the temperature down in the rest of the greenhouse. This station is capable of hosting 20+ 1020-size trays at a time. I’d be happy to share some information and resources about that if folks are interested.
Hope this was helpful. Row trays have saved us many seed starting hours over time. We’re happy to be sharing this process with you. Please share your questions and comments.
