Growing Bulbs in ContainersGrowing Bulbs in Containers
Save Space and Brighten Up Your Landscape in Every Season with Flowering Bulbs
There are so many choices for growing bulbs in containers that it is necessary to decide first of all, what you are looking for in your container gardening plan.
- Are you anxious to see an early bloom of color in the spring after a long winter?
- Perhaps you want some to plant some tender bulbs because of their dependable bloom through the summer?
- Do you feel fall bulbs are always fun to extend the growing season when your garden is fading away?
- Do you want to force some bulbs inside in winter to perk up your spirits and remind yourself that spring is not far away?
As you can see, when growing bulbs in containers, it is possible to have these wonderful flowers year round. There is no need to wait for spring tulips and daffodils to enjoy bulb gardening year round. Flowering bulbs can be used in outdoor containers, grown in a raised bed for cut flowers, or grown as house plants year round.
As you can see, you should have a plan in mind before you order any bulbs. Check the listing and ideas above, peruse catalogs, wander through greenhouses and nurseries at various times of the year to get a good idea of the many flowers that are actually bulbs you can be grown in containers. Because there is such variety in flower bulbs, I’ll be devoting a page to each bulb season. There are, however, some basics to growing bulbs in containers.
The first question that comes to mind is what size pot should I choose when growing bulbs in containers. There is no right answer here, as some bulbs like to be planted deeply, while others prefer surface planting. The size of the bulb also enters into this choice.
As a general guideline, an 8-inch pot is a good choice to start with. You can put about 5-6 bulbs in a pot this size. Use your judgment when planting these bulbs. Most bulbs don’t mind being crowded. They can be planted touching each other. If you have large bulbs, you may only be able to get 3 in the pot, or maybe only one extremely large bulb. You will be able to get an idea of how many bulbs fit in the pot once you start laying them in. If you want a container for a large splash of color on your deck or patio when growing bulbs in containers, a 16-inch pot will not be too large.
Any type of container is suitable for bulb growing. Many bulbs are delicate in nature and when planted indoors look well in china bowls and silver dishes. If you are planting outside, terra cotta pots look great, but because of their porous nature, will need more watering than pots made of plastic or fiberglass. Whatever type of pot you decide on, the most important consideration in a container is drainage. If there are no drainage holes in your container, it is always possible to drill a few.
Potting Mixture for Growing Bulbs in Containers
As always, every gardener has their favorite potting mixture for bulbs that they swear by. The one constant in choosing a good potting mixture for bulbs is that it must have good drainage. A good recipe for bulb potting mix contains equal parts of soil, sphagnum moss, and perlite or vermiculite. If you prefer not to mix your own mixture, commercial “soil-less” potting mixes can also work well. Having large amounts of organic matter in your potting soil is not recommended as this could encourage disease and rot in your bulbs.
Forcing Bulbs – Bring Spring Flowers Indoors and Shorten Winter Garden Doldrums
Forcing bulbs is a sure way to raise your winter spirits, especially if you live in the colder Northern climates. There’s nothing like the cheery nodding of daffodils or planting tulip bulbs in a container to chase away the winter blues and bring light to your eyes.
For the new gardener, the process of growing bulbs indoors and coaxing them into bloom is called “forcing bulbs”. Forcing bulbs in containers is easy, but you have to think ahead if you are aiming for a beautiful display of spring bulbs during the late winter season. September/October is the ideal time to pot up your spring bulbs if you want them to bloom 3-4 months ahead of schedule. Your choice of bulbs will have a lot to do with your success in this area, so choose carefully, especially if you are new to forcing bulbs. Check the catalogs or ask your nursery vendor which varieties are preferred when you are forcing bulbs.
When forcing bulbs it is best to plant only one single variety per pot. The reason you usually see only one color in a pot of forced bulbs is that even in the same species, different colors are apt to bloom at different times. When you are forcing bulbs, you want to see a container with a mass of color. This can happen only if you plant a single variety per pot. If you plant several varieties per pot or even several colors of the same variety, your display is apt to be spotty and unattractive. If you want many colors, it is better to plant several pots of different colors. When the containers bloom, you can move them around to get the mass of color you are looking for. As the blooms in one container fade, you can remove it and give the next colorful bloomer the spotlight.
Planting Your Bulbs
Choose a bulb container for your planting. There is a commercial pot for bulbs that is about 4″ deep and 10 -12″ wide. This allows for root growth and many bulbs to be planted in one pot. Cover the drainage hole with screening or a coffee filter. Add a bottom layer of planter mix. A good recipe for bulb potting mix contains equal parts of soil, sphagnum moss, and perlite or vermiculite. If you prefer not to mix your own mixture, commercial “soil-less” potting mixes can also work well. Having large amounts of organic matter in your potting soil is not recommended as this could encourage disease and rot in your bulbs.
The mix should be deep enough so that the tops of the bulbs will be about 1″ below the rim when planted. Plant the bulb with the flat end facing down and the tip facing up. Place the shoulder of the bulb to shoulder in the pot with about 1/4″ spacing between them. The bulbs are planted in the top of the pot to allow room for root growth.
When you plant large bulbs such as tulips and hyacinths, cover the tops with 1/2″ of soil. With daffodils, don’t try to cover their necks, only the flattened portions of the top of the bulb. Cover the smaller bulbs like crocus with 1/2″ of soil.
Once the bulbs are in place, cover them with more potting mixture. Label each pot with the type of bulb and variety. If they are going to go into cold storage at this time, water them thoroughly by setting the container in a pail of water and letting it soak until the surface of the soil is moist. The planting is ready for cold storage and you are now starting the process of forcing bulbs.
You Need Cold Storage When Forcing Bulbs
Bulbs need cold to bloom. Bulbs already have the flower inside them. It takes 12 – 14 weeks of cold treatment, (temperatures between 40-55 degrees) before a bulb will flower. This cold period gives the bulbs the time they need to develop a strong root system. Set your pots in an area that is cold and dark, such as an unheated cellar or garage. An old refrigerator in the garage set to that temperature is ideal. If you live in an area of moderate cold, it’s alright to store your bulbs outside in a protected box. Cover them with peat moss, styrene pellets, or other protective covering. Just be sure your bulbs are never exposed to freezing temperatures. During this period, roots require moisture for growth. Be sure to check your bulbs and keep the soil moist (not wet) during the period of cold storage when forcing bulbs.
At the end of the cold storage phase, when the sprouts are 2-5″ high and the roots can be seen from the drainage holes, place the containers in a cool 60-degree room. After a week or two in this intermediate room, they are ready to be brought into the house at normal room temperature. Be sure to give them adequate light at this point, or the plants will become leggy.
How to Extend Your Bloom Season into Spring
If you stagger your plantings when forcing bulbs, you can extend your blooming season way into spring. This takes a little more thought, but if you enjoy bringing spring early to counteract the long winter, try this method of forcing bulbs for a long blooming season indoors:
Pot up three containers at a time. They don’t all have to be the same bulb planting. For instance, you could try planting tulip bulbs in one pot, daffodils in another, and a hyacinth bulb in the third pot. Or if you prefer, you could try planting tulip bulbs in all pots, but each one a different color. Place them in storage, and two weeks later repeat the process. Do this several times and you will have a gorgeous display of bulbs throughout late winter into early spring.
If you don’t want to be constantly planting bulbs in containers, plant all your containers at once but keep them dry. Label your pots with the type of bulb and date you want to move them into cold storage. When you are ready to start forcing bulbs, water the containers thoroughly as mentioned above and move them into cold storage.
Forcing Hyacinths in Water
Another way to consider forcing bulbs is to do this in water. Both hyacinths and paperwhites can be forced in water. The important thing to remember in both instances is that bulbs will rot when sitting in water, therefore be very careful when using this process to keep the bulbs above water.
To force hyacinths on water, set a bulb just above(but not touching)the water in a forcing vase or another container. Special hyacinth forcing vases are available in nurseries and florist shops. Place the bulb in cold storage as described above. The process of forcing hyacinths in water is the same as described above. The only difference is that you must check the water. If it gets cloudy or foggy, change the water. When the roots are long enough, after about 10-14 weeks, bring it out of the cold store and follow the procedures listed above.
You can also try this procedure that many people have had success using:
Store bulbs of an easy to force hyacinth variety (check the catalog or with your nursery vendor) dry in a paper bag in your refrigerator for 8-10 weeks. Then put them on the water as for regular forcing (see above), anywhere in indirect light. As they grow roots and leaves, give them more light but avoid direct sun. Experiment with this system and see if it works with the bulb variety you have chosen as it’s a much easier way to force hyacinths in water as you don’t have to remember to keep checking the water.
Forcing Paperwhites in Water
Paperwhites are also forced in water. These are very easy to grow because they don’t need cold storage to bloom. Follow this procedure for forcing paperwhites:
Choose a container that is about 4″ deep and around 10″ wide that has no drainage holes. Spread 2″ of stones, marbles, colored glass pebbles, etc, on the bottom of the container. Place your paperwhite bulbs, pointed tips up, on this layer. Place them as close together as possible for an amazing flowering display. Add a second layer of stones, glass, etc., up to the shoulders (the fattest part of the bulbs) of the bulbs. The tips should still be showing.
Add water up to the base of the bulbs. Don’t cover the bulbs as this will cause the bulbs to rot. Keep the bulbs in an area heated to about 60-65 degrees. The bulbs don’t need light while the roots are developing. Keep an eye on your bulbs and add water as needed. When roots have developed, move your paperwhites to a sunny area. They prefer a really bright and sunny light at this point, but don’t like a lot of heat. If they get too warm, your plants will become leggy. Once your plant’s flower, move them to a cool spot with indirect light.
As with other forcing bulbs, you can extend the paperwhite season, by starting more pots several weeks apart.
After the Flowers Fade
Keep your plants in good health by providing water and sunlight. Once the danger of frost has passed, move the pots outside to an inconspicuous place where the foliage can continue to mature. Do not cut back the foliage as this is where the bulb gets its food for next year’s bloom. Once the foliage has died, plant them in the ground for continuous growth for years to come. Some people force the bulbs a second time, but the bloom is never as satisfactory as the first time around.
Discard hyacinths and paperwhites forced in water as they seldom bloom again
If you’ve decided this is a process that really interests you, be sure to keep a journal of your progress. This can be a simple notebook recording the name of the bulb, date planted, date put into cold storage, and date of bloom. If you want more meticulous records, keep more details such as length of bloom time, how many bulbs in a pot, species of a bulb, area of storage, etc.
In this way, from year to year, you can improve on your indoor display when forcing bulbs. You will be able to extend your bloom time, control flowering schedules, and tailor your display from year to year to fit into your desired schedule and display area. Before you know it, you’ll have all your friends and neighbors oohing and aahing over your skill as an indoor gardener.
Fall-Blooming Bulbs in Containers – Extend Your Garden Season with Fall Bulbs
If you’ve never considered planting fall-blooming bulbs in containers, you are missing out on quite a show. Although everyone is familiar with the spring-blooming bulbs like tulips and daffodils, fall blooming bulbs are almost like the stepchildren of the bulb family.
These are great plants to use in containers because even if they are not hardy in your area, you can still have a fall showing of colorful blooms. When the show is over, you can move the entire pots to a garage or basement and bring them out again next year. If you prefer, you can lift the bulbs and store them bare root over winter to protect them from frost. Check out the monthly garden tasks for September for more information on storing bulbs through the winter months.
When you are ready to re-plant the bulbs, discard any bulbs that have shriveled. Check them over for rot or any signs of disease or insect damage. Be sure your containers are clean and sterilized. Follow the general directions for planting bulbs in containers and plant only firm healthy bulbs in your garden containers.
The range of fall blooming bulbs is not as extensive as that of spring bulbs, but you still have quite a few choices that will extend the bloom time of your garden containers. Although I’m discussing growing fall-blooming bulbs in containers, these fall flowering bulbs can also be planted in the ground which is why I am listing the plant hardiness zone for each bulb.
Colchicum (Fall Blooming Crocus):
Blooming Season: Sept-Oct
Hardiness Zone 4-9
Comments: These are actually corms and are shipped in late August, early September. They bloom within a few weeks of planting. Showy flowers. Colchicums can be placed in a dish of pebbles with enough water to keep the corm bottoms wet. They’ll bloom very soon without the addition of soil. Each bulb produces 5-10 flowers.
Crocus speciosus (True Autumn Crocus):
Blooming Season: Sept-Oct
Color: Violet Blue – Mauve
Hardiness Zone 4-9
Comments: These are shipped in early September and should be planted immediately for fall bloom. A very easy plant to grow and is the hardiest of the autumn crocus bulbs. Resembles its spring cousin, the crocus we all know and love.
Cyclamen Hederifolium (Fall Blooming):
Blooming Season: Early to late Fall
Hardiness Zone 5-7
Comments: This bulb is the daintiest of fall blooming bulbs. Useful for containers, but also great when planted in woodland gardens. Spreads easily
Lycoris (Spider Lily):
Blooming Season: Late summer -Early Fall
Color: Shaded of Reds
Hardiness Zone 8-10
Comments: An old fashioned favorite. Best if kept dry in the summer while the plant is dormant. A member of the Amaryllis family.
Blooming Season: Late Fall – Early Winter
Hardiness Zone 7-10
Comments: Nerines are amongst the finest of the autumn flowering bulbs and are members of the amaryllis family. They are very long lasting when used as cut flowers. This bulb is a member of the amaryllis family
Sternbergia (Autumn Daffodil):
Blooming Season: Fall
Color: Golden Yellow/White
Hardiness Zone 6-9
Comments: Resembles the crocus flower. Prefers a sweet soil. A member of the amaryllis family. Combines well with blue or purple fall crocus in containers.
Table of Contents
- 1 Growing Bulbs in Containers
- 1.1 Save Space and Brighten Up Your Landscape in Every Season with Flowering Bulbs
- 1.2 Forcing Bulbs – Bring Spring Flowers Indoors and Shorten Winter Garden Doldrums
- 1.3 Fall-Blooming Bulbs in Containers – Extend Your Garden Season with Fall Bulbs
- 1.4 Related