Growing bulbs in the Florida garden
Did you know you can grow bulbs year after year in Florida?
When we talk about bulbs, there are “true bulbs” and bulb-like plants. Your true bulbs are those plants that contain all the plant parts, such as roots, an underground stem, a flower bud and fleshy leaves. These plant parts are stored in an underground structure called a bulb. These underground storage structures make them very tough.
Caladiums are a favorite in the Florida garden. Caladiums are a tuber, similar to potatoes.
(Photos courtesy of Nicole Pinson)
Examples of true bulbs include lilies, tulips, society garlic and amaryllis. Other “bulb-like” plants such as gladiolus and caladiums are comprised of corms, tubers, tuberous roots or rhizomes. For generalization purposes, most plant guides refer to both true bulbs and bulb-like plants as bulbs.
Picking the right bulbs for Florida can be a bit tricky. But, once you learn which bulbs are best for Florida, you can easily grow them and have color throughout the year. Not only do bulbs provide beautiful flowers, but they also have strappy leaves and interesting foliage. The different shades of green add structure, variety, texture and contrast to the garden.
Because of our tropical and subtropical growing conditions, you will want to plant bulbs that are adapted to our region for the best success. A great resource is the publication Bulbs for Florida available at UFDC.ufl.edu/IR00002886/0001. This guide provides information on selecting, planting, caring for and propagating bulbs. Table 1 lists bulbs that are most desirable and easiest to grow in Florida. Stick to this, and you will add diversity and beauty to your landscape.
Growing bulbs and bulb-like plants adds texture and interest to the garden.
Some of my favorite bulbs are African lily (also called agapanthus), amaryllis, blood lily, caladium, rain lilies and crinum. Be sure to read the cultural notes for the bulbs you choose, because the notes include additional tips on care, location and pest control.
If you want to experiment, try planting some bulbs from Table 2, or as UF/IFAS refers to them, “Bulbs for the Avid Gardener.” These bulbs may be a bit more challenging, but they are worth trying. One bulb that I am going to try from this list is a favorite cut flower- Alstroemeria.
Avoid growing bulbs — or giving bulbs as gifts — that do not grow well in Florida due to our temperatures and warm winters. These bulbs, such as tulips and some lilies, will not receive the cold temperatures they need to grow well and bloom.
Some of my favorite Florida gardens contain bulbs that are planted in clumps among other landscape plants. Imagine looking out at a backyard garden and seeing shell ginger, crinums, irises and amaryllis among traditional shrubs such as hibiscus or plumbago.
I use bulbs to brighten shady spots and add them to bouquets. Many times, I am surprised by them when they pop up. Most bulbs grow well in sun to part shade.
Amaryllis is a bulb that can be easily grown in Florida. After a few years, divide it and share with others, or use it to fill flowerpots or other areas of your yard.
When planting bulbs, make sure to plant the right side up. Follow spacing and fertilizer recommendations. Bulbs such as amaryllis will produce seed heads after flowering, and if left on the plant, they will reduce the amount of flowers next year. In order to have more blooms, cut off old flowers and seed heads. However, resist the urge to cut off yellow leaves until they turn completely brown because these leaves are making and storing food or energy for the bulb.
Eastern lubber grasshoppers are one of the biggest pest problems with bulbs like lilies and crinums. Control them when they are young nymphs, rather than when they are large grasshoppers. Handpicking is the least toxic method of control. When young, these grasshoppers congregate on the plants in the morning and evening, and this makes them easy to remove. Pests such as aphids and mealybugs can be controlled with insecticidal soap or horticultural oil. Fungal problems, such as rust and anthracnose, often develop during periods of high rainfall or are spread by wind. If the disease persists, apply a fungicide for disease control.
Bulbs add color and interest to the garden, and they are easily propagated. Depending on the bulb, you can propagate them by division, offsets, bulblets or cuttings. Plus, you will have bulbs to share with friends and family, or to transplant and fill up pots or sparse areas of your garden. Growing bulbs in Florida is easy and enjoyable.
For more information on this topic, check the following reference, which was a primary source for this column: “Is this a bulb? The difference between bulbs, corms, rhizomes, and other bulb-like plants.” Visit GardeningSolutions.ifas.ufl.edu/plants/ornamentals/is-this-a-bulb.html.
Nicole Pinson is an Urban Horticulture Agent in Hillsborough County. She gratefully acknowledges Judy Gates, UF/IFAS Extension Hillsborough County Master Gardener for her help in preparing this article. For additional information, you can reach Pinson at (813) 744-5519, ext. 54145.
Published June 1, 2016
“The late John Van Beck, former president of the Florida Daffodil Society, donated the bulbs for the most recent study. Brent and Becky Heath donated bulbs for the first study,” Stamps says.
The Heaths, third-generation bulb growers and daffodil hybridizers in Gloucester, Va., own Brent and Becky’s Bulbs.
Inspired by circumstances in his own yard, Stamps has been testing the bulbs in a series of outdoor 16-square-foot testing beds at the Mid-Florida Research and Education Center to learn which ones thrive in Central Florida.
Stamps has cultivated various bulbs under precise conditions, controlling every aspect of the plants’ growing conditions: soil type, pH level, percentage of light and shade, watering and temperature. As many as 30 cultivars have been included in each study.
Stamps says the growing conditions of each study mimic the conditions of the local region, allowing him to offer results that Central Florida gardeners can duplicate.
Each plant and each bloom has a tag on which Stamps records planting date, blooming dates, number of flowers and length of bloom, which in turn are tracked in a database.
Stamps has published his results in the proceedings of the Florida State Horticultural Society, which disseminates information to local extension agents.
BOOK ON BULBS
In another test garden several counties northeast of Apopka, the Flagler County Extension Service is giving bulbs the “cold shoulder.”
“In Bunnell, the test gardens are exposed to real elements of nature,” says Linda Van Beck, Florida Daffodil Society president and widow of the former president.
The bulbs, which in this case are all daffodils, have been neglected for the most part, rarely even watered.
“That may sound terrible, but based on the results from that garden, we know how certain bulbs behave in Central Florida when left to their own devices,” says Van Beck of Tallahassee.
She doesn’t test bulbs herself. In fact, she isn’t a gardener. It’s the mystery of the plant and the explorations of scientists that excite her. She is writing a book, as yet untitled, detailing the habits and history of daffodils in North Florida’s Zone 8.
The chapters address a range of topics relevant to growing daffodils. Practical tips, such as which watering methods daffodils respond to best, draw on Van Beck’s years of bulb observation.
“As soon as the bulbs flower, stop watering. Since they aren’t taking up water at that point, watering the plants will result in a pool of water that could rot the bulb.”
Van Beck’s advice is reliable, based on comprehensive research that includes observations of daffodils growing in hundreds of locations in the state. Van Beck is somewhat of a plant historian, too, and is writing a chapter on Florida’s daffodil heritage.
“Few people know that at a point in time, the world’s largest daffodil nursery was located in Alachua,” she says.
Late in the book, Van Beck’s educated speculations point to the future of daffodil growing, a future Van Beck hopes to influence through her writings.
For example, bulb viruses could compromise the success of daffodil growing in the South if gardeners aren’t careful to avoid them. Van Beck’s advice: “Buy from reputable catalogs and nurseries with high standards. These are the sources for virus-free bulbs. Be picky.”
One chapter of the book addresses Central Florida Zone 9 daffodil gardening.
Van Beck looks to the Bunnell test gardens as a resource. Apparently, results from the Bunnell test gardens counter conventional wisdom about daffodils.
“Daffodils are very particular. It seems that they get a feel for their location in the fall, and decide whether they are going to bloom in spring. The contractile root of a daffodil shrinks back in unfavorable conditions,” Van Beck says.
Considering this, it is amazing that out of 30 varieties that were planted, eight grow as perennials, returning year after year, despite extreme drought conditions and a single fertilization each year as the bulbs began to sprout.
Ruth Micieli of the Flagler County Extension Service describes the test gardens she oversees as “very close to natural conditions.”
In October 1998, she and her volunteers planted a set of donated bulbs like the ones that Stamps planted in Apopka.
“We covered the beds with pine straw in spring and summer to prevent evaporation of water and weed growth. We did weed consistently and also hand watered during the worst times of drought,” Micieli says.
The daffodils that survived and thrived were the same daffodils Stamps had success with, only this time plant care was more minimal and record keeping less precise.
“We’re starting over this year with a new group of volunteers, and we plan to record results from the garden more carefully,” Micieli says.
Still, the results from her previous studies affirm what Stamps has also concluded.
Gardening: Bulbous plants for Southwest Florida
Daffodils and tulips are my favorite flowers because it was a sure sign of spring in Connecticut when they began popping up in the fields and yards. While we cannot grow daffodils or tulips this far south we do have some bulbous plants that are beautiful.
Most of the year these bulbs show pretty, green leaf-like foliage in the garden. One of the most beautiful bulbs we can grow here in South Florida is the amaryllis. They come in varying shades of pinks and reds.
Bulbous plants will thrive and produce these beautiful flowers year after year with proper care. These plants have thickened underground storage organs which enable them to survive unfavorable environmental conditions. These underground organs are also the propagative units of the plants. Not all bulbous plants are true bulbs. Other underground storage organs include corms, tubers, tuberous roots and rhizomes.
A true bulb is a compressed stem or basal plate bearing a flower bud enclosed by thick, fleshy scales called bulb scales. Some true bulbs such as narcissus, amaryllis and tulip are protected from drying and mechanical injury by dry and membranous outer scales called a tunic. Other true bulbs such as lilies are called non-tunicate or scaly because their outer scales are succulent and separate, giving the bulb a scaly appearance.
A corm is a solid mass of stem tissue with a terminal bud on top. Axillary or lateral buds are also produced at nodes on the corm. The solid stem structure of the corm is protected against injury and water loss by dry leaf bases that are like the tunic that encloses true bulbs. Gladiolus is a corm.
A tuber is a thickened underground stem with many buds on its surface. Tubers are covered with a tough skin rather than a tunic or scales like true bulbs and corms. An example of a tuber is a caladium.
Tuberous roots, such as dahlia, are true roots and lack nodes and inter-nodes. Buds are present only at the crown or stem end of the root.
Rhizomes are thickened horizontal stems growing along or below the surface of the ground. Underground rhizomes of canna and calla produce roots on their lower surface and send shoots above ground.
Florida’s climate is favorable for growing many tropical and subtropical bulbous plants. Unfortunately, many of the common bulbs of northern states such as tulips, hyacinths and daffodil do not grow well in Florida. These bulbs flower poorly or not at all. With special treatment many of these northern bulbs will grow and bloom the first year. Recovery and planting the following year are not recommended since they rarely flower again.
Most bulbs thrive in a sunny location. Some, such as caladiums, do best in partial shade. Heavy shade should be avoided as it will cause thin spindly growth and poor foliage color and flowering. Bed preparation is important for successful bulbs. A well-drained soil is important. You should till and amend the soil with three to four inches of organic matter and fertilizer.
Dig holes to the recommended depth for the various bulbs and plant with points facing up. Firm the soil around and over the bulbs and water.
Mulch the beds to control weeds. Weeds that do grow through the mulch should be pulled before they become firmly established in the bed.
Fertilize once or twice during the growing season with a special bulb fertilizer. Bulbs such as tulips which are discarded after flowering do not need fertilizing since they have enough stored food to last through the blooming period.
Water is crucial when growing bulbs and it is important that they not dry out during growth and flowering. Always keep the soil moderately moist, except when drying off at the end of a growing period.
A good cultural practice is to remove dead blooms before seeds are produced. Flowering in the following season will be reduced if seeds can set. Removing seeds also adds to the aesthetic value of the planting and may prevent disease problems.
Many bulbous plants grow best if left in the ground year after year while others may become crowded and bloom poorly. Digging and replanting encourages more uniform and larger flowers.
True bulbs, amaryllis, hyacinth, develop miniature bulbs, known as bulblets, which grow into offsets. Offsets can be separated from the mother bulb and replanted into the beds. Depending on the kind of bulb, it could take several years before they reach flowering size.
Corms, such as gladiolus, produce new corms on top of the old corms, which wither. Miniature corms called cormels are produced between the old and new corms. These can be separated from the mother corms and stored along with the new corms over winter for planting in the spring. Cormels also require two to three years to reach flowering size.
Tubers (caladiums), tuberous roots (dahlia) and rhizomes (canna, day lily) are propagated by cutting them into sections, each containing at least one bud. Tuberous roots that are broken off without a bud are worthless.
Bulbous plants can be moved anytime except when they are in bloom.
Some examples of bulbs, corms, tubers, tuberous roots and rhizomes and their flowering seasons:
Eileen and Peter Ward have owned a landscape and lawn maintenance company for 35 years. Eileen can be reached at [email protected] or 239-394-1413.
- Amaryllis – spring
- Amazon lily – winter
- Aztec lily – spring and summer
- Blood lily – summer
- Crinum – spring and summer
- Society garlic – spring, summer and fall
- Spider lily – spring and summer
- Gladiolus – three months after planting
- Tritonia – spring and summer
- Watsonia – three months after planting
- Caladium – summer to fall
- Glorioso lily – March to summer
- Elephant ears – spring
- Dahlia – early summer
- African lily – summer and early fall
- Butterfly lily – spring
- Cana – spring to first frost
- Day lily – spring and summer