- Baker Creek: Heirloom and rare seeds. A massive variety of interesting (and eye-catching) plants. Unclear exactly how much more difficult these are to cultivate than the more basic varieties. They have a concise growing guide for most of the species I plan to grow.
- Botanical Interests: Basic seeds that seem more mainstream than the wild and rare varieties. They are available at the local garden store and affordable, so I usually find myself with many of their seed packets in my cache. They also a sowing guide. They have both vegetables and flowers.
- Wild Seed Project: A Maine-based native plant-focused seed organization that focuses primarily on pollinators. I currently have dozens of their seeds in a winter box in the back. Fingers crossed until Spring.
- Sow True Seed: Open-pollinated, heirloom and organic seeds. They also have mixes for sprouted seeds. They have in-depth growing guides for specific plants that include harvesting seeds for next planting.
- Gardener's: Everything for the home enthusiast gardener (read: me). Lots of high quality raised bed materials, irrigation systems, etc.
- Johnny's Selected Seeds: Seems to have everything - geared more towards actual farm operations. I ordered Agribon-19 and PVC clips, but they seem to have everything. Like the pro version of Gardeners.
There are a number of commercial starter tray/pot options. I first got a few dozen pressed-peat starters. I am inclined to just use household materials and recyclables to make as many as I can. There are methods to make plant pots out of newspaper.
Update: I've started using some of the 72-cell trays and I have to say, I am getting really good results. They were $5 each and seem reausable if handled gently. I think I can turn out 200 seedlings every few weeks, which is way more than I'll have room for. It felt silly buying plastic when there's so much plastic waste that can be reused, but the form factor just works super well with the self-watering tray and condensation cover.
I've found that the compost I ordered in bulk is too dense and rough to start seeds - they've done far better in a loose and soft soil.