Growing Bulbs in Outdoor Planters
Many bulbs are well-suited for planting in outdoor containers or planters. You will follow the same procedure as required for bulbs in the ground, but there are a few additional considerations for successfully growing flowering bulbs in a confined space.
Multiple bulbs of the same type can be used to create a mass planting or ‘naturalized’ effect in a large planter or you can use a layering technique for different flowering bulbs to create a sequence of blooms throughout the season, or even year.
First, you will want to select a flowering scheme for your bulbs. Do you want all bulbs to flower at approximately the same time for a special event or do you want to create a ‘mass display’ resembling an in-garden planting? Or, would you like to have a series of blooms to continue through your growing season, or even through the year in some regions?
Soft Color Schemes
Pastel shades are probably the easiest way to create a soft look. It is nice to break the pastels up with white or cream blooms somewhere in your container. This will give a clean look instead of a washed out one. Another pleasant combination is to choose one color and use two different shades of it, along with a white or cream to soften it up. Example: Deep-purple, pale-purple and cream.
Bright Color Schemes
For a burst of color choose either three consecutive colors on the color wheel making sure you pick flowers with intense deep, rich color. Consecutive colors are: (red, orange, yellow) (orange, yellow, green) (yellow, green, blue) (green, blue, purple)
Or choose complementary colors—colors that are opposite on the color wheel: purple and yellow, orange and blue or red and green
Select Flowering Bulbs
Once you have decided on a flowering scheme, it’s time to choose your bulbs for your planters. You will find flowering bulbs are typically placed in one of three categories :
- early for Spring
- mid season for late spring through Summer
- late bloomers for the Fall/Winter
When grouping bulbs in a planter, be sure to select varieties with similar chilling, light and water requirements.
Here’s a simple planting scheme for a spring-flowering bulb container:
- Plant daffodils at recommended depth and add approximately 2″ of soil.
- Plant tulips and top with more soil.
- Add smaller bulbs such as crocus and grape hyacinths.
- If desired, top the planted bulbs with pansies, which will last through the winter in some regions.
Make sure that your bulbs are watered regularly to keep the soil moist, but not soggy. As always, be sure to use a planter with good drainage, placed in a location that gets adequate sunlight. Finally, to mask the dying foliage of spring-flowering bulbs, you can inter-plant a perennial such as hosta or daylily to extend the enjoyment of your planter.
Choosing a Planter for Flowering Bulbs
Good drainage is vital to bulbs, so choose pots with large holes. Terracotta pots are great for spring flowering bulbs because they are porous and allow water through their sides as well as their drainage holes. This lessens the chance of bulb rot during our wet, mild winters. Wood planters also to drain quite well.
A well-drained soil is essential for bulbs. Add either 10% crushed pumice rock or washed sand to a container potting soil.
When planting bulbs, be sure to fertilize with bone meal or bulb food at planting time, and again, just after blooming. Although these products are virtually interchangeable, there is one major difference: since it is organic, bone meal is slower to take effect. As a result, bone meal makes a better over-winter feed, while bulb food supplies a burst of feed in the spring.
Caring for your New Pot of Bulbs
Place your planters outside in a sunny location where they will receive natural rain or can be watered. Since most bulbs are much hardier than necessary for mild winters, there is no need to shelter them. Apply a light mulch during heavy-frost periods, once the foliage and buds starts to show above the soil. Keep your container evenly moist, and avoid digging near the developing plants.
Moving the Pot
When in bloom, bulb planters can be moved to the best site in the garden and if the pot is small enough, can even be brought into the house. After blooming, the pot can be stored out of sight in a garage or shed; or carefully planted over for a spring, summer and fall show. During each re-planting, be extra careful around the developing bulbs.
A second simple, 3-tiered potted design for beginners:
1. The first tier of 5-7 tall yellow tulips form the backbone of the planter.
2. The second tier of grape hyacinths (Muscari spp.) create a soft-looking ring around the container and offer a color contrast to the tulips.
3. The bottom tier of yellow-centered primulas, hug the pot, mirror the color of tulips, and conveniently bloom at the same time as the rest of the pot.