Starting tender bulbs indoors: starting containers?
I will soon start my tender bulbs indoors, which are tuberous begonias, caladiums, and dahlias.
I'd like suggestions for what to start them in. I'd been using peat pots for the begonias. However, I always end up chipping off the peat when I'm ready to plant, as the roots really don't penetrate through in the length of time these are potted up. If I'm going to do that, I might as well use something cheap. Paper cups seem like they would be ideal, that is assuming you can even buy paper cups retail anymore, and not plastic. If there's a waxy coating, that's probably a good thing. I would set the cups in a big plastic tray.
With the caladiums, I just don't know what to do. I have a couple of heat mats. But even with starting them on the heat mats, I have never had any luck with them actually sprouting, until it was really warm out, and I put them right outside: like early June. My house is cold. Maybe the heat mats start waking them up from dormancy, but I have not done a comparison with the years when I gave up and just plunked them in the pots. One year I tried using a nursery tray with a plastic lid, and covering it with a blanket. All I got then was rot.
I have a lot of those, like 50, in 3 different colors. Potting them individually doesn't seem to make much sense. I have used small shallow plastic trays that trayed bulbs from big box stores came in. Lined with newspaper to keep the soil from washing through, then filled with potting mix, and the caladiums just pressed into the soil, and not buried.
The dahlias are bigger, I'll use old nursery pots for them lined with newspaper, unless someone has a better suggestion for me.
All will ultimately be removed from whatever they are started in, and planted into large deck pots outdoors. The dahlias will go straight into the garden.