Normally I start my clones out in April inside under 400 wt Halides and by the end of May they are in 3 gal pots ready to go outside in partial shade to aclimate them for a week. As for holes go. I dig large holes almost 4 ft across and a little over kneecap deep. Now as for soil and nutes go, I use Promix HP for my base soil as it contains canadian sphagnum peat moss which holds moisture real well while staying very soft and light allowing roots to grow great. I then mix in some extra perlite, a 20% earthworth mix for the local worm factory and one bag of organic composted chicken manure.
Now as for nutes, Tea's. I will cycle different teas during the week during their growth phase. But I use 1 drop per gallon of Super Thrive, great shit! Here is one of my recipes.
I mix in a 5 gallon bucket that when ready in 24 hrs get mixed into a 55 gal barrel for watering.
3 - 8 oz cups of Bat Guano 10-2-2 of something close to this.
2 - 8 oz cups Organic Composted Chicken Manure
10 - TB Spoons Organic Soluble Seaweed
5 - oz Molasses but I only add this once a week or every other week.
Strain everything and then dump in to the 55 gal barrel and fill to the top with well water. The ony difference is sometimes I use straight Worm Castings in place of the Bat Guano or Chicken Manure.
Last but not least is foiliar feed my plants 2 times a week with a much more diluted version of the above. Now a trick for you guys that don't want to spend $300 buck on a atomizer for feeding is to buy yourself a cheap electric paint gun like the Wagoner Power Painter, basically it's a baby atomizer for about $50 or cheaper. This works fantastic and great to use in the evening time after things cool down a bit. I like spraying early evening as the plants stay wet longer absorbing the nutes.
Hope this helps out a little.
Mr G