I have several plants (some flowers, some shrubs) in 1 and 2 gallon buckets. I want to know how to plant them correctly. I intend to spread mulch of some sort over the planting area afterward, so I think the top should stick out a little. The ground is pretty flat as well, so no surprises there. What do I need to do to make sure they survive?
This is the time to prepare the soil in the ground to match the soil in the bucket. There could be large ph or drainage differences between the soils. I made this mistake a couple of times worth noting:
I planted a goji berry tree in native acid soil and discovered afterwards that goji requires an alkaline soil, so I tried in vain to apply lime and save the tree, but it was too late. Lime takes considerable time to change the ph of the soil and should be applied well ahead of planting.
Another example of a mistake in planting was with a stella cherry where I failed to give it a raised bed in the heavy clay soil we have. Heavy rains followed the planting and drowned the cherry's roots. I learned afterwards that cherries don't like wet feet.
So now is the time to be sure the soil doesn't need more prep before transplanting is done. Another thing to consider is sun/shade tolerances, though shrubs and flowers seem like they would be very forgiving in this area.
If the soil type and drainage and the amount of light matches the plant's requirements, the plant should survive.
Be sure to untangle any roots and dig a hole much larger in diameter than the bucket, then spread the roots out. Don't put leaves or mulch in the hole to compete with the roots for nitrogen. Put the mulch on top. The raised look should be fine, but may require more watering because of the increased drainage.
For the azalea, the soil needs to be acidic, not alkaline, and they usually prefer a little shade during the hottest part of the day. If you haven't yet dug over where you want to plant, you should take the chance to do this now, incorporating humus rich materials (organic material, well composted, so things like composted animal manures or even your own compost heap material). Let the soil settle for a week, then dig holes larger than the containers you have. Plant what's in the containers at the right distance apart to allow room for spread of each plant, at the SAME depth they're in currently, in other words, don't leave the rootball sitting proud of the ground, it should be level with it or just fractionally below, so you can't see any root. If the plants are root solid, by which I mean the roots have curled round and round tightly, tease these out, and plant without cramping the roots into the hole. If they are not in that state, then just scratch down the outside of the rootball lightly and then plant. Water in well, then put your mulch over the top, making sure you put less than an inch directly against the base of the trunk/stem of the plants, or leave a little space around the mainstem clear of mulch. The reason I say to plant level with the existing soil is that the mulch (assuming its organic and not inorganic) will gradually rot down, and if you've planted the rootballs proud of the existing soil, these will eventually be sitting in open air, and that isn't something your plants will enjoy.