Growing a holly tree in a container can be a challenge, particularly if you try to grow the holly tree from a seed. The growing process from a seed will take multiple years before a seedling will sprout. It is because of this that it is a better idea to start with a seedling instead of a seed when growing a holly tree in a container. The holly tree seedlings will develop into great ornamental trees in a container, as long as you provide the tree with what it needs to survive.
Selecting a Container
After you have a holly tree that you want to work with your next step is to find a container. The container that you select needs to be large enough to accommodate the growth of your holly tree or holly shrub. Generally a 15 to 20 gallon container is going to be large enough to handle the growth needs of a dwarf holly tree. When selecting your container make sure that it is designed for good drainage and that it is strong enough to contain your holly tree as it matures and gets taller.
Soil and location
Holly plants prefer well-drained and sandy soils, although they grow in all types of soil, you should avoid water logging soil. Holly performs best in partial shadows, although most of its varieties can tolerate full sunlight. The plant likes a little acidic soil. If organic substances (such as shredded or chopped bark) are used during planting, it helps in reducing soil pH and improves soil quality. At the time of planting, using sulfur-based fertilizer can reduce the soil ph.
Since the holly tree is grown in containers, so it is more sensitive to drying. So make sure the container is well fed regularly.
Planting Your Holly Tree
The next step is to plant your holly tree in your container. To do this, simply place your holly tree in the container and fill in the container with the soil/coffee ground mixture. Pat down the soil to secure the holly tree in place. Soak the holly tree and place it in the sunlight. Give your holly tree about a month to establish its root system before feeding it a balanced, basic slow release fertilizer.
General Care Tips
After your holly tree has been planted in its container it will need regular care. You will need to give it water, just enough to keep the soil moist but not muddy. You will also need to feed your holly tree once a year. Finally, you will need to prune your container grown holly tree during its non-growth seasons. This will help you to manage the size and shape of your holly tree.