10 Things You Need for Successful Seed Starting
It seems like just yesterday we were all clearing the garden and prepping for the long, cold winter. Luckily, most of us didn’t have to deal with frigid temperatures and mountains of snow, but the seeming lack of a real winter may have caught a number of gardeners off guard.
Boom…here it is. Seed starting time already.
Some of us use the depths of winter to leaf through seed catalogs, longing for the day when the birds begin to chirp and the grass turns green. In the absence of this mental cue, many of us may be caught in a scramble to gather everything we need (or think we need) to get those early starts going.
Meh, no sweat. I’ve put together the top 10 things every gardener needs to embark on their seed starting or plant propagation adventure, all wrapped up in a neat little blog post. Look through the list seed starting supplies, find out what you need, and go get started.
Seriously.
All the spring flowers, the magnolias…everything is bloomed already, which is freakishly early. We may have a longer than normal growing season ahead of us, so there’s no time to waste. Get your seed starting started already (*please note: Mother Nature totally has a way of messing with us gardeners, so don’t be surprised when she throws a late frost at us. Amiright?).
The 10 Seed Starting Essentials
1. Seed Starting Trays
This one is sort of tricky, because what most people would consider a seed tray is actually two things. The first is the tray itself. This is usually a standard 1020 tray (1020 just means 10″ x 20″). This is just a flat, open tray without cells and with or without holes in the bottom depending on your preference. With holes allows for drainage, without holes will not.
***Protip: Many people use no hole trays in conjunction with the celled trays below (which have holes) as a self-watering seed tray system. This works great for plant propagation and seed starting.
2. Celled Inserts
The other component of a seed starting tray is the insert, and as the name implies, this is inserted into the 1020 tray. An insert is typically thin grade plastic and has multiple cells in one sheet – up to 72 depending on the orientation – and can also usually be broken apart into smaller “cell packs”. It can’t be carried on it’s own because it’s so flimsy, which is why you need both. Our most popular sizes are 606 and 806 inserts. The former has 6 cell packs of 6 cells for 36 total cells, and the former has 8 cell packs of 6 cells for 48 cells. This makes for very efficient seed starting since you can place one or two seeds in a cell, and when the seed germinates you can pop out the “plug” and plant it.
3. Propagation Mat
If you’re going to be seed starting before Mother Nature would otherwise allow them to grow, you’re going to need to use the same trigger she does to tell your seeds its time to grow. That trigger is heat. Specifically, soil heat, or more accurately, soil temperature. In order for seeds to germinate, the soil needs to maintain the proper temperature. In the early spring it’s usually still too cold for this, but we can trick our seeds by using a propagation mat. A propagation, or heat, mat (also known as a seedling heat mat) is placed under your seed tray and keeps your soil nice and toasty around the clock, which leads to higher germination rates in less time. Seeds like the same temperatures that you do – between about 60 and 80 F – and that’s the exact range a seedling heat mat is great at maintaining. I’ve had seeds sprout in as little as 1 day using a heat mat.
4. Grow Lights
Most of the time if you are seed startin early, you will be starting them indoors. I start mine in my basement, and others may start in the garage or other such places. The key here is that these places don’t have a lot of light, and light is one things that seedlings are absolutely going to need. That’s why it’s best to get a florescent grow light system of some sort to provide essential light to your fledgling plants. You can either get a system, complete with integrated stand, or a stand-alone fixture you can hang yourself.
***Protip: Keep the lights about 1-3″ inches from the highest leaves of your plants to prevent stretching from light starvation.
5. Seeds
I suppose it goes without saying you’re going to need seeds to do any seed starting. There are plenty of places that sell seeds, and plenty of seeds to be bought, so look around to find exactly what you want.
6. Soil
You’d think that soil was an easy one. Just walk outside and scoop some into the cells of your insert and you’re all set, right? Well, first of all not everyone has the luxury of having good soil, and secondly, just because your seeds will grow in your native soil doesn’t mean you have to or even should use it for seed starting. It’s good to use a sterile, soiless, peat based growing medium. This way, you know there are no nasties lurking in the soil plotting to destroy your plants. Fill your inserts with the growing medium, place your seeds, and cover with a little compost if you have it.
7. Soil Sieve
A sieve isn’t essential, but it will make your life a little easier. It’s already easy enough to fill your insert with growing medium, burrow a hole for you seed, drop it in, and cover it up. What the sieve will allow you to do is place all your seeds, and then shake a fine layer of medium or compost over the top of the seeds. This way, the amount of soil on top of your seeds is uniform and not too tightly packed, which could prevent your seed from breaking through.
8. Transfer Pots
Transfer pots come in a lot of shapes and sizes, and depend on what you’re growing and how long it will be before you plant in the ground. Basically, when your seedlings get too big for your seed tray, they need to be moved to bigger pots. This way, the roots have more room to stretch and the plant can remain healthy until it’s time to go outside. The most popular transfer pots are between 3-5″ square pots, and usually the associated carrying trays.
9. Frost Protection
Spring planting is always a gamble, and more often than not we gardeners are going to jump the gun. That’s probably especially true this year. Inevitably, Mother Nature will throw one last frost at us after we have taken the plunge and put plants in the ground. These early spring cold temperatures can spell disaster for your young plants. That’s where frost protection fabrics come in. They are simply a light and water permeable plastic fabric that you can drape over your plants that will keep them just warm enough on frosty nights to stave off freezing.
10. Composter
Compost is the best thing you can do for your soil, and everyone can benefit from using it. Keep in mind, if you want happy plants, then you need happy soil. And compost makes any soil very, very happy. There are plenty of small compost bins designed if space is at a premium or you won’t need much compost, but there are also plans out there to build your own larger compost bin. Decide what’s right for you and start composting now.
Bonus Seed Starting Tip #1: Soil Test Kit
A test kit won’t necessarily help your seed starting or plant propagation efforts, but it will help you ensure your seeds flourish once transplanted to the ground outside. A soil kit will tell you if you soil is deficient in any specific nutrients, if there is something present that’s harmful, and how healthy your soil is. This is critical information, because if your soil is lacking, your plants will be too.
Bonus Bonus Seed Starting Tip #2: Fertilizer
I should mention fertilizer for seed starting. If you use compost, chances are you won’t need any fertilizer. But, it can help your seedlings grow faster and stronger. I found it was easy to over fertilize and damage my plants, but if you can make it work, good for you.





Very,very informative ,Im building my own GreenHouse wish me luck. This will be my frist time starting my vegtable’s from seeds.
Comment by Idell Cowan — March 26, 2012 @ 8:18 am
My wife and I are looking to start a large (for us) quantity of heirloom starts next spring and are in the planning stages right now.
This is a very helpful article. I would have never thought to use a sieve to spread soil over the top of the seeds…
Also, you guys seem to have the best prices on seed pots that I have been able to find!
Comment by chris @ backacrehomestead.com — July 11, 2012 @ 4:34 pm
I have used many of the products from these folks, and I can tell you the quality, quantity and variety of products is absolutely fantastic. The ProMix seed starting has got to be the best I have ever used! Fantastic prices and really helpful people. Won’t buy from anyone else!
Comment by Colleen — August 22, 2012 @ 1:59 pm
This answered a lot of questions I had. Just got a greenhouse and I’m already playing around with seed planting so I will be able to judge when to start planting so I will have veggies and flowers in spring.
Thank you for such an informative article.
Comment by Rosie — October 8, 2012 @ 5:50 pm
You seem to have almost everything I need to start my horticulture garden. I hope I will still be able to get the right kind of technical information especially about the wheather being in Southern Africa. I cant wait to start!
Comment by Belita — February 1, 2013 @ 3:42 am