Q. I needed some advice for planting small trees or roses in containers on a balcony. Please walk me through the steps of planting in containers, when is the best time to plant, should the container be placed directly on top of a plate for drainage? I don’t want to stain my white balcony floor. A. The first step is selecting the container. The larger the plant you want to grow, the larger the container must be to accommodate it. Weight is an issue on balconies. Make sure your balcony can support the increase in weight from a plant and container full of wet soil. Expect the container to weigh about 8 to 10 pounds for each gallon capacity, plus the weight of the container and the weight of the plant. Gravel is not needed at the bottom of the container. Omit the gravel that many people suggest. If the gravel is not clean or sterile, you run the risk of adding plant disease to your soil mix. Select a soil mix that is as light as possible for patios. Light soil mixes are used for houseplants and usually contain a soil amendment called perlite. Perlite is a lightweight, crushed volcanic rock which has been heat treated and expanded so that it contains a lot of airspace. Perlite adds bulk or volume to the soil mix without much additional weight. Plus it is good in holding water. Perlite is used in light weight soil mixes. It adds bulk and improves water holding of a soil. After purchasing the plant, gently remove it from its container and put it in a clean bucket of water. Let the roots soak submerged overnight. In the morning remove the plant from the bucket. Gently rinse off the soil surrounding the outside roots. It is not important to remove all of the soil. Just the soil from the outside inch of the root ball. Once the soil is removed, put the plant back in the bucket with fresh water covering the roots while you prepare the container. Never put roots of any plants in direct contact with dry soil. Put enough wet potting soil in the bottom of the container so that the top of the root ball of the new plant rests 1 inch below the top rim of the container. Using wet potting soil, fill the void between the roots and the inside of the container. Use enough potting soil so that the top of the root ball is barely visible. Add about 1 inch of water to the container to settle the potting soil around the roots. The potting soil will “disappear” as it fills the voids among the plant roots. Add more wet potting soil and repeat this process until the soil barely covers the top of the root ball. You are finished potting the plant. If the plant selected was for its flowers such as a tree rose, fertilize the plant with a fertilizer applied to the soil at the beginning of a growing season and once a month while it is flowering. Use a fertilizer high in phosphorus which promotes flowering. If the plant selected was for fruit production such as a lime tree, apply a fertilizer to the soil just before flowering begins and again after harvest. Use a fertilizer high in phosphorus which promotes fruit production. Watering will be as needed and when the soil starts to become dry. One of the easiest ways to determine this is to use a water meter sold for houseplants. They are relatively inexpensive and gives you a general idea how wet the soil might be. Moisture meters used for houseplants can give you a general idea how dry or wet the soil is. Another tactic is to nudge or slightly lift the container to get a general idea of its weight. Containers become lighter as they lose water. A third way is to push a pencil into the top of the soil. Pencils push easily into wet soil but are more difficult to push into dry soil. You will water the container enough so that about 10 to 15% of the applied water runs out the bottom of the container. This is important to prevent the buildup of salts in the soil which will damage the plant. Any basin that collects water after an irrigation should be emptied soon after it fills. The container can rest directly in the basin.