Anything that holds enough soil and has drainage holes in the bottom can be a container. If there are no drainage holes, drill some using a large bit on a portable drill. The pot should be big enough and deep enough for the plant or plants.
Think outside the pot and select unusual containers to add personality to your yard.
A 15 to 18-inch pot is a good minimum size, although a bigger pot has more capacity for holding water and is less likely to dry out too quickly in our hot summers. Shallow containers work well for succulents, because they need to dry out between watering.
Using a pot stand or pot feet, elevate the container off the ground so that it can drain properly.
Use a soilless mix, either by making your own or purchasing a commercial mix. No single potting mix is ideal for all container-grown plants. (See website references at end of article for specifics about additions to potting mixes.) Most potting mixtures become compacted over time so it is best to replace containers with fresh soilless mix at least once a year or every other season.
Select (1) something tall for the back-a thriller, like a grass or canna, (2) a filler-something shorter for the middle area, and (3) a spiller to cascade down the sides.
Look carefully at where you will place your containers and note the amount of sun and shade. Then choose plants with similar requirements for light and water. To help coordinate the colors in the container, choose a piece of fabric or picture of a piece of art that you really like and take it with you when you purchase the plants.
If the pot is to be viewed from all sides, place the thriller in the center of the pot. After planting, water thoroughly so the potting media can get in and around the root ball of the plants and eliminate air pockets.
Don’t be afraid to use shrubs, perennials and tropicals in containers along with annuals! The pot to the right demonstrates good textural contrast and variety.
For a pot 18 inches in diameter, you need approximately 5 to 9 plants. Aim for a variety of foliage sizes and textures so that each plant stands out. If all the flowers and foliage are similar, the pot will look too busy.
Fertilization: Fertilizer needs can vary by plant but a general plan is to use a controlled release fertilizer at the time of planting. Additional fertilizer is needed in eight to 10 weeks. Liquid fertilizers can be used once a week at half strength or every two weeks at full strength.
Grooming: Pinch back plants as they grow to maintain their shape and deadhead as needed. Annuals that trail-like petunias, million bells, and lobelia-appreciate a midsummer haircut. The easiest way is to prune the entire plant back by about one third.
Watering: Requirements vary considerably and are affected by wind, light (full sun versus cloudy conditions), temperature, humidity, container size and type (clay pot versus plastic), the type and amount of potting mix, and the type of plant. A top dressing of mulch over the potting mix surface significantly reduces moisture loss. Consider a drip irrigation system with a timer. (See website reference at end of article.)
Herb and Vegetable Containers
Plant edibles with ornamentals. This pot has edible peppers with ornamental flowers and foliage.
Plant tiny vegetables or herbs first. Add flowers later. Space plants closer than if in the ground.
Vegetables are easier in larger pots.
Use colorful trellises and pretty obelisks for supports.
Vegetables and herbs need to be placed in a location with at least six hours of sunlight each day.
Shade from overhangs, buildings or furniture will decrease the total number of hours the container receives sunlight, so take that into consideration.
Yellow cherry tomatoes and melampodium contrast with a cobalt blue pot.
Four Season Containers
For a container plant to survive the winter, a good rule is to choose plants that are hardy to two zones colder. In our zone 7b area choose plants hardy to zone 5b.
Plant pansies with an evergreen for fall and winter. In late spring replace pansies with summer blooming annuals.
Plant bulbs in the fall and after they bloom in the spring slip them out of the container and plant in your yard. Then plug some warm season annuals into the empty spot.
Use colors that will work from spring to fall. For example, use dark yellows and purples like purple fountain grass and golden melampodium. Add dusty miller for contrast. If a plant fizzles out, pop it out and replace it.
Pollinator Garden in a Pot
Want a pollinator garden but don’t have the space? Plant a container.
This pollinator container has pentas, zinnias, anise hyssop, vinca, butterfly weed, coneflower, helenium, oregano, and achillea.
Planting window boxes uses the same principles as containers. To create needed depth really make use of those spillers. ‘Silver Falls’ dichondra and creeping Jenny are great assets for trailing from window boxes.
Websites for More Information