f, When new growth appears on the plants. Check the growth cycle expectations for each type of plant. Even drought tolerant plants need water to get established and then water can be cut back. List the plants and we can help search the info for you. Don't see why you can's start immediately. Drought plants should be alright in hot and humid country. Check with the local supplier of the plants for transplanting info. I hope you are not starting from seed. Aloha

The dead ones look very wet. There are even algae on the surface of the mix. I think they've rotted. Also I suspect the pots are too big for babies. I'd pot them on to much smaller pots.

You have essentially two ways to maintain this plant arrangement: as a single hedge, where all the shrubs grow together into a single mass ... or as single shrubs, where each is separate from the other. Regardless of which design you choose, the consistent aspect of shrub trimming is that the base is trimmed wider than the top, so that sunlight reaches the lower foliage and it continues to live. (Where the back faces the house, it will be cut straight and not matter as it will not be seen.) If the top is wider than the base -- as is seen in the shrub at the left side of your house -- then lower foliage will eventually begin to die off and the shrub will assume the form of a tree, as if it were on little stilts. (See this beginning in the shrub, second from right, in your original picture.) In an individual shrub, trimming in a ball shape would be incorrect because it undercuts the base, shading it by the top. A dome shape would be correct because the base is wider (or no less wide) than any portion above it. That said, most landscape designers do not use a series of dome shapes in a line anywhere near as much as they would use a hedge, which is simpler to look at and simpler to maintain. The series of balls is usually the result of a homeowner thinking it is cute and maintaining what would have otherwise been a hedge, in that arrangement. After deciding between a single hedge or 4 individual shrubs, one would next decide on how this is best maintained: through regular, tight clippings designating the outer limits of the foliage ... or through annual coppicing, where all trunks of the shrub are cut to the ground. They quickly regrow with the final result looking simultaneously thick and bushy, and loose and natural. The problem for you using coppicing here is that all stems (trunks) grow out in a relatively uniform length. If they ended up nearly reaching the window bottom, they would also be nearly reaching the door.

How often depends on the soil and the weather. And if the natural soil is much different in texture than the soil the tree came in watch that this soil does not dry out despite frequent watering, that keeps the existing soil moist. What often happens when trees are planted with intact root-balls is the soil around the tree having a greater attraction for water, so that the tree is always drying out despite watering. The resulting susceptibility to drought does not end until the tree roots into the native soil. Plants often come from retail outlets with severe nutrient deficiencies, that may not always show much in the color of the foliage. So fertilizing your new tree enough to be sure it is in good shape is worthwhile. But otherwise summer fertilization is undesirable if it results in the production of a major flush of tender new growth, in any situation where falling behind on watering even one time on a hot day is possible.