The seed catalogue wants you to believe that starting seeds requires a dedicated room, a wall of equipment and a monthly subscription to consumables. It does not. People have grown gardens from windowsills and margarine tubs for centuries. What has changed is that a small amount of the right gear now makes success far more reliable and far less fussy - so the honest goal of this guide is to tell you which few things actually earn their place, and which are theatre.
Everything here serves the biology from the last guide: containers that protect drainage and oxygen, a way to deliver the warmth switch, and enough room to keep seedlings under strong light once they emerge. Get those three right and the brand names do not matter.
Containers: anything that holds mix and drains
A seed-starting container has exactly two requirements: it holds an inch or two of mix, and it has drainage holes. That is the entire specification. Everything beyond that is convenience, tidiness or ego. Let us go through the real options honestly.
Recycled pots and packs - yogurt tubs, deli containers, the plastic six-packs last year’s transplants came in, newspaper pots you roll yourself. Cost: nothing. Punch drainage holes in the bottom, wash them if they held plants before (a rinse in dilute bleach guards against damping-off pathogens), and they work exactly as well as anything you can buy. The only downsides are that they look scruffy and they are not standardised, so a tray of mismatched tubs is fiddlier to move and water. For a first season, this is a perfectly good answer and I would not talk you out of it.
Cell trays (plug trays) are the workhorse of the trade for good reason. A rigid tray divided into cells - 6, 12, 72 or more - keeps each seedling’s roots separate, waters evenly, pops out cleanly at transplant time, and drops into a standard watering flat. Buy the sturdier ones and they last many years; the flimsy black ones that come free with plants crack after a season or two. If you buy one dedicated thing, make it a few good cell trays and matching solid bottom flats (the flats without holes, for bottom watering - more on that later). Cell size matters: small cells (say 72 per tray) are efficient for lettuce and brassicas that transplant young, while big, hungry seedlings like tomatoes and squash want larger cells or an early pot-up so they do not get rootbound and starved.
Soil blocks are the enthusiast’s choice: a hand tool compresses moist mix into free-standing cubes with a dimple for the seed, no container at all. The payoff is real - roots “air-prune” at the block’s edge instead of circling, so transplant shock nearly vanishes, and you buy no plastic ever again. The cost is a fussier routine, a specific mix recipe that holds together, and a learning curve. Wonderful once you are hooked; overkill for your first trays. File it under “upgrade later if you love this.”
Peat and coir pellets (the discs that swell when wet) are convenient and beginner-friendly, but they lock you into buying consumables, the netting can restrict roots if you forget to peel it, and they dry out fast. They work; they are just the most expensive way per plant to do a simple job.
The takeaway: do not spend money here on your first season if you do not want to. Recycled containers grow identical plants to premium trays. If you do buy, a set of decent reusable cell trays plus solid bottom flats is the purchase that keeps paying off.
Heat: the one upgrade that changes results
Warmth is the switch that most often decides between a fast, even flush of germination and a slow, patchy, rot-prone mess - specifically for warm-season crops. A seedling heat mat sits under the tray and holds the mix around 70-80°F (21-27°C) regardless of a chilly room. For peppers, tomatoes, eggplant, basil and other heat-lovers started in late winter, this is transformative: germination that might straggle over three weeks in a cool room happens in under one, evenly, with far fewer rotted seeds.
Two things people get wrong about heat mats. First, the mat is for germination, not for growing. The moment seedlings are up, most come off the mat - continued bottom heat on emerged seedlings encourages leggy, stretched growth and dries the mix too fast. The mat’s job ends when the sprouts appear. Second, not every crop wants it. Cool-season crops - lettuce, spinach, peas, brassicas - germinate fine, even better, in ordinary room temperatures and can be inhibited by too much heat. Putting lettuce on a heat mat is a common waste. Match the tool to the crop.
If you garden mostly cool-season crops, or start seeds in a warm house, you may not need a mat at all. If peppers and tomatoes are your ambition and your house runs cool in late winter, a mat is the single highest-return purchase in this guide. A cheap thermometer or a mat with a thermostat probe takes the guesswork out.
Space and the shelf math nobody mentions
Here is the trap that catches enthusiastic beginners: germination takes almost no space, but growing on takes a lot. Fifty cells fit on a tea tray. Fifty seedlings under strong light, potted up, hardening off, needing room to not shade each other - that is a serious chunk of your home for six weeks. Every year someone sows two hundred cells in February and discovers in April they have nowhere to put the survivors.
So plan backwards from space, not forwards from enthusiasm. A simple, popular setup is a metal wire shelving unit with a shop light hung under each shelf - it turns a few square feet of floor into three or four growing levels, each its own little climate. But even without buying shelving, do the honest arithmetic before you sow: where will these plants physically live at their biggest, indoors, before the garden is ready? Sow to that answer. Starting fewer plants well beats starting many and killing most for want of light and elbow room.
Ventilation belongs in the space plan too. A small fan on a low setting, running a few hours a day, does two quiet jobs: it dries leaf surfaces and mix crust enough to suppress the fungal diseases that flatten seedlings, and the gentle breeze stimulates sturdier, thicker stems (plants respond to movement by bulking up - the same reason a wind-exposed tree is stockier than a sheltered one). It is a small thing that prevents a lot of grief.
Three honest budget tiers
To make this concrete, here is what a working setup looks like at three levels. Any of them grows good plants.
Free / scrappy. Recycled tubs and six-packs with holes punched in, a bright windowsill supplemented by any lamp you own held very close, bottom-watering in a baking tray, a sunny spot for warmth. It works. It is more fiddly and light will be your limiting factor (the next guide is entirely about fixing that), but people grow whole gardens this way. Start here with zero guilt if money is tight.
Sensible starter (a modest one-time spend). A few good reusable cell trays plus solid bottom flats, one seedling heat mat for the warm-season crops, and one or two inexpensive shop lights on an adjustable hang. This tier removes almost all the reliability problems of the free setup and the gear lasts for years, so the per-season cost falls fast. This is where I would point most beginners who have decided they are in for more than one spring.
Enthusiast. A wire shelving rack with a dedicated light per shelf on a timer, a thermostat-controlled heat mat, a small circulating fan, and maybe soil-blocking tools once you are hooked. This is a home nursery that can raise hundreds of plants of consistent quality. You do not need it to succeed; you arrive at it because you fell in love with the process.
The pattern across all three tiers is the same: light and warmth are worth money; fancy containers are not. Spend where the biology is, not where the catalogue photography is. Speaking of light, it is the single factor that decides whether all this setup produces stocky, garden-ready transplants or pale, floppy disappointments - and it is misunderstood often enough to deserve the whole next guide.