Container planting is not hard and it can be great to experiment with different combinations of plants and containers. The first thing you want to do is choose the right plants for the container you are using. Make sure the plants can tolerate the light exposure the container will receive. Shaded areas need shade plants and sunny areas sun lovers. All plants in one container should have the same light requirements. You should also consider the mature size of the plants and their growth habits. Plants selected should also need the same moisture requirements.
Not all containers need to be flowering plants - foliage is very important in containers. Variegated foliage on plants can add interest even when not in bloom. You can have a great container garden with only foliage plants. In general containers look best when there are different colors and plant textures.
Tropical and perennial plants are being used more often in containers. Tropical plants can be brought inside for the winter or given away at the end of summer. Many perennials will over winter in the right container. Ornamental grasses and sedges, small hosta and heuchera, dianthus, ferns, even dwarf evergreens can be used in containers.
Ornamental vegetables and herbs can also be enhanced by planting in containers - ornamental peppers, cabbage, kale and basils. Variegated thymes are excellent trailers, and variegated mints also have a trailing habit when grown in a container. Smaller okras have hibiscus- like flowers and Rosemary and lavender can add fragrance to containers.
When you start with small plants it is easy to crowd the container. When mature, some plants will outgrow others and the whole group will suffer. Because many plants are bought in four or six packs, it is tempting to plant them all in one container. If you did this early in the season don’t be afraid to remove some the container will fill in.
To start planting take the largest plant for your container out of its original pot. If the root balls are packed and twisted, gently pinch the bottom of the roots. This will keep your roots from growing in a circle and possibly strangling the plant.
Now fill the container with planting medium so that the plant’s root ball will be about one inch below the container edge. Take your companion plants and arrange them in the container for visual interest, moving them around until you get the right look. With the smaller plants, add some soil under them so that the root ball tops are all the same height.
When the plants are arranged to your liking, fill in the space around them with moistened planting medium. Tamp it down between the sides of the container and the root balls and between plants. You want to cover the tops of the root balls only slightly, leaving about an inch below the top of the container to hold water.
To keep containers healthy and attractive, they need to be watered on a schedule that suits the plant material in them. Do not let plants wilt between watering; press your finger into the soil and it feels dry, water. Late in the season when plants are large and the root mass fills the container; the planting medium may have a hard time holding enough water for them, so you may have to water more frequently.
If a container has become too dry, the planting medium may shrink away from the sides of the container causing water to run down this gap and out of the container. You will need to soak the container in a larger container of water for several hours or let a hose run at a trickle in the center of the container.
To keep containers blooming, the plants will need regular fertilization. If the planting medium you used was Miracle Grow or other fertilized mix, it is usually good for three months. In the Bluegrass, plants placed outside in early June may need fertilization in late August. That will keep them going until frost. If the planting medium did not include fertilizer, the best way to feed container plants is with a water soluble fertilizer. Mix it according to label directions for container plants and apply it about every two weeks.