For me that means saying goodbye to 80% of my kitchen counter. I have lights under the upper cabinets that are my surface lights most of the year, but come seedling season (early February through early May for my growing area) they become my grow lights and most of my kitchen counters turn into a mini nursery.
My calendar looks like this:
I’ve put in info about my average last and first frost dates, how many weeks before and after those dates, because that’s how I know when to seed things out and plant them into the garden.
This calendar tells me when to seed something out indoors (‘si’ for seed indoors, in red), when to seed something directly into the garden (‘so’ for seed outdoors, in olive), when to transplant the little guys (‘t’, in bright green) and when to expect to harvest (the cells that are outlined). This helps me plan my crop rotation and to some extend also when and how I can put up my harvest.
For my little plant guys I have a few different methods of seeding them out. For example my tomatoes and all of the brassica (cole crops like cabbage and cauliflower) go into cut to size paper towel (and toilet paper :D) rolls I save throughout the year. I do this for different reasons: Tomatoes set deep roots, so I want them to be in a tall seedpod to give them the best start I can. I usually do not transplant them, but seed them in a few inches of seed starting mix and then add a little to the top as they grow. Tomatoes put out roots off their stems and this seems to work rather well for me. YMMV. The brassica are a bit different and I put them into the deep rolls because once I put them out into the garden they will be vulnerable to cutworms, so I want to give them a little bit more protection with the higher lip around the tender little shoots.
I also use origami seed pots with planting mix (made over the winter from newspaper pages, while watching the rare but of TV), the little pods that expand in water (rarely) and I do this in the foil turkey roasters with the clear lids, because they are taller than the little seedling greenhouses, so I can let the seedlings grow taller while still keeping them protected from the predation of Felis sylvestris catus:
Around this house those are the prime predators of indoor seedlings, despite the laid back image they are trying to project... That is just to lull us into a false sense of security, so that they can then POUNCE onto any and all baby plants and devour them, only to 'give them back' at 3am :D You may not need to protect against those, so YMMV ;)
One thing I do not have marked in this calendar is the hardening off that needs to happen to any seedling you take into the great outdoors. I usually do about a week, week and a half worth of it prior to planting them out, depending on what plant it is. At that point our back patio becomes the plant nursery. It provides a bit of shade and overall a gentle introduction to sun and wind and a bit of rain.
Because I have this plan with the growing season and how long each plant takes to mature I can plan around my garden and if I am behind by a week or two (like right now…) I can prioritize easier. Another thing I have been able to do with this plan has been to adjust how things work in my particular micro-climate. Just because the seed packet says something will take 90 days to mature does not mean that it’s exactly 90 days. It may be 80 days in my backyard, but 112 in yours. It’s all about learning how things work :)