For my first attempt at growing standards from tubers I bought about $100 worth of tubers - probably not too smart but I think I pulled it off so far. I used Stevens book which has lots of details but it's very poorly written IMO. I have a few questions (most of these will help me refine my technique next season) -

1. I put the tubers in a plastic germination tray with a roughly equal mix of potting soil, peat and pearlite. I drilled about 20 holes in the tray. Seems like these trays are a little shallow and even with the holes I had to be very careful not to overwater. Are the trays a good idea if you are growing 20+ tubers? Should I make or try to find a slightly deeper tray?

2. I had to start my tubers in the garage which probably gets down to 50-60 deg at night in the spring. Even though most had small sprouts when I got them, they seemed to take off really slow until I put some desk lamps on them at night to give a little more heat. I'm guessing that keeping the tubers around 70 to 80 deg is optimum. I also noticed that one person here uses grow lights. I moved my trays outside every day for light but the trays flex thus disturbing the soil. I think the grow lights are a better idea as soon as the leaf is visible but these don't provide any heat as far as I know. I saw the heating mats but they are $25 each (one tray per mat). So my question is - Since I can't start the tubers inside the house and my garage can get down to 50 deg in the spring should I add bottom heat and if so is there a larger mat that will cover more trays (for less $ per tray)?

3. I have both upright standards and pendulars. Stevens goes into great detail on pinching and staking the standards but he says nothing abouy the pendulars. I saw one site that suggested pinching the main stem of the pendulars to generate more side stems. Is this accurate? Also, I bought quite a few 16" wire baskets with the coconut mat. Are these too large? I later noticed that they have 12 and 14" units.

Interestingly Stevens says the pendular tubers can go right to the basket skipping the germination tray. I don't understand this except that it may be because the baskets have much better drainage?

4. For the final potting should I use clay pots for the upright standards? Reason I ask is that in the past I have potted the same type of plant - one in a plastic pot, one in clay right next to each other and the soil in the clay pot dries much faster which is not surprising. Also, and I know this is hardly scientific, but the plants in the clay pot seem to grow faster than the same plant in the plastic pot. Perhaps there is more oxygen available to the roots.

5. I've also been reading a lot on custom potting mixes and I know there is lots of debate on this but I'm thinking a bonsai type mix may be safer for a beginner for the final potting. I have installed an automatic drip system so frequent watering is not a big deal although I know it make take some time to dial things in.

Thanks so much for any advice,

Alex

I have 2 trays in which all tubers are showing leaves but are growing slowly (I got a late start). However, one of my trays shows no leaves yet and the buds are still real small. I don't think there is rot because I was real careful and at this point I almost let the mix dry out between watering.

It's still getting down to 50 deg or so at night here, 80 in the daytime. You think I can save these by bringing them back inside and applying a little bottom heat?