New Mexico Master Gardeners
 

 BULBS for Albuquerque

by Ellen Reed, Lifetime Master Gardener
Edited by Ruth Bronson, Lifetime Master Gardener

The terms bulb, corm, tuber and rhizome refer to swollen underground structures that plants use to store nutrients and water. The general term 'geophyte' is now used to include all of the above.

True bulbs, if cut in half vertically, reveal the components you would expect to find in a bud, namely, flower and leaves. Bulbs are layered much like an artichoke. Onions, tulips, lilies, and narcissus are true bulbs. Corms are solid, enlarged stem bases: examples are crocus and gladiolus. Rhizomes are swollen stems that grow horizontally usually underground and send up leaves and flowers at intervals. Iris are the best-known rhizomes. The term 'tuber' is applied to any plant with underground storage parts that don't fit the above categories. Common tubers are potatoes, dahlias, gloxinia and Anemone blanda.

The structures developed in response to unfavorable environmental conditions such as cold or drought during various times of the year. Since they originated in many geographical areas they are suitable for most garden situations. They need dormancy at some time of the year either in or out of the ground. Dormancy is broken by moisture and/or warmth. The original source of a species is a clue to when plants need dryness. Tender summer-blooming bulbs from the Southern hemisphere must be dug, kept dry and protected from freezing in winter. Hardy spring-blooming ones must be relatively dry when dormant in the ground in summer.

Bulbs need nutrients and water available when they are in active growth, i.e. have roots and leaves. Phosphate is their chief requirement, and super phosphate or ammonium phosphate may be incorporated into the soil under the bulb at planting time. It remains available for many years and leaches very slowly. Bone meal is too alkaline for our soils. Narcissus require high levels of potassium, but there is enough in most New Mexico soils. Nitrogen must be added annually in the spring when the leaves are actively growing. A foliar feeding of soluble fertilizer after bloom keeps the leaves vigorous so they can develop strong, healthy bulbs for next year's bloom. Keep watered while leaves are green Water once or twice a month from September through the winter as the roots are growing then.

Most of these plants need a site with full to filtered sun when their leaves are green. It should be away from tree roots that compete for fertilizer and water. or extra food and water must be provided. The middle to rear area of a flowerbed is a good place as emerging perennials or annuals can hide the fading foliage. A south-facing wall or driveway may reflect too much heat for tulips but be a good place for borderline hardy bulbs such as Lycoris or Ranunculus. Clumps of small bulbs look attractive near large rocks. Mark the site so bulbs won't be dug accidentally.

To prepare an area for planting loosen soil and remove any large rocks. Add humus such as well-rotted manure or compost to lighten clay soils and improve water retention in sandy soils. Dig a hole large enough to hold three or more bulbs, work phosphate fertilizer into soil below bulb level, add about an inch of perlite over fertilizer to improve root development (and as a marker in future digging), place bulbs on the perlite layer, refill hole, level soil and water.

Generally bulbs should be planted at a depth of about 3 times their greatest diameter. Plant deeper in sandy soil, and plant tulips deeper in warmer climates. It is difficult to determine top from bottom with anemones, so plant them on edge. Fritillaria should also be planted on their side so the cup-like bulb will not collect water. Small bulbs may be planted individually by making a small hole with a trowel. Large bulbs if all are planted at the same depth tend to bloom at the same time and height.

To prevent squirrels from digging up bulbs, plant them in wire cages. Newly planted bulb beds can be protected form cats' digging by covering the soil with wire fencing. Surround emerging Iris reticulata with a low, folding fence to keep birds from pecking the flowers. Snails and slugs may eat colchicum buds as they emerge and may hide in daffodil foliage as it withers so use snail bait to control them. Aphids may carry virus from one plant to another and should be controlled. Thrips are a problem on iris, daffodils and gladiolus. Spray if necessary. Wash off gladiolus and tuberose foliage with water to control spider mites. If bulb foliage is twisted and streaked with yellow, it may be infected with a virus, and those bulbs should be removed to the garbage or burned to prevent spread of disease to healthy plants. 

Most hardy bulbs are planted in the fall and bloom in the spring. Plant them as soon as they are available except tulips, which may benefit from about 6 weeks refrigeration and should be planted after the soil cools. Healthy bulbs are firm to the touch. They are available from local nurseries and in greater variety from mail order catalogs. Small bulbs should be planted as soon as available so they won't dry out.

Hardy Spring Blooming bulbs
Narcissus (Daffodils, Jonquils)

By choosing varieties with early to late bloom times, you can have narcissus in bloom for nearly 2 months. They prefer sun or very light shade. In Albuquerque they persist and multiply. When clumps become crowded or the bulbs work to the surface, dig them after the foliage withers, replant the largest bulbs, and share the excess with friends or replant elsewhere.

Daffodil classification is explained in many books. Most classes (except the Poeticus -commonly called "poets"- and doubles) do well here. The poets are tender and may bloom in a warm, protected site. Paper whites are best forced indoors for Christmas or New Year and if they are planted by Thanksgiving, may bloom for the holidays. Outside in a protected area they may bloom later. Double daffodils may blast in spring heat and wind. Red rims on the caps may burn in the hot sun.  One class of narcissus with narrow leaves, multiple small flowers and sweet scent is called the "jonquil". (Additional material on Daffodil culture by Debbie Vigil may be found at my web site).

Tulips

In warm climates such as Albuquerque tulips must be planted in a place that stays cold in winter. The varieties that grow best here are the lily flowered tulips, many botanical or species tulips, Darwin hybrids, and hybrids of Gregii, Kaufmanniana, Fosteriana (Emperors). Like daffodils, doubles tend to blast in spring heat. "Broken" or Rembrandt tulips are infected with a virus that can be spread by aphids to other bulbous plants so they should not be planted near lilies or other tulips. When flowers become smaller, and the clumps are crowded, they should be dug, the bulbs dried out in a cool, dry place, and the largest ones replanted. The tiny bulbs will bloom eventually if they are planted in an out-of-the-way place and allowed to grow.

Crocus
 

Crocus species and their hybrids love our hot, dry summers to ripen their corms.  The species have smaller blooms and some are very early. They look weedy in lawns and will get too much water when dormant unless planted in buffalo grass lawns. The species multiply more freely, persist better, and have more flowers than the larger flowered Dutch crocus. Crocus should be moved only when completely dormant, as their roots will not regrow if disturbed. Fall blooming crocus bring a promise of spring to the late garden. Crocus sativus (a fall bloomer) is the source of saffron. It will grow in a warm, sunny spot. Harvesting stigmas does not ruin the flowers.

Hyacinths
 

Hyacinths should be planted where their perfume can be enjoyed; i.e. near doorways and walks. The spikes of blooms become more open over the years. If they are happy, the bulbs will split and send up two bloom stalks. This is a signal to dig, divide and replant. The best colors are blues, white, light yellow and a clear pink "Lady Derby." To my eye, the reds and oranges are muddy.
French Roman hyacinths or "fairy" hyacinths (H. orientalis var. albulus) have dainty loose multiple spikes of flowers. Their bulbs multiply freely.

Other small spring-blooming bulbs
There are several small, mostly blue-flowering bulbs that are effective planted in groups or drifts. If allowed to go to seed and the soil around them is not cultivated too vigorously when the little sprouts are emerging in the spring they will spread nicely. These include Chionodoxa, Muscari (grape hyacinths), Scilla, Pushkinia, and Ipheion all of which also have white-flowered varieties. The Muscari may self-sow too vigorously. Muscari typically sends up the first foliage in the fall but it will winter over and resume growth in early spring.

Scilla siberica is cobalt blue and about 6 inches tall. S. tubergeniana appears very early, light blue and has a spicy scent. S. Peruviana may be hardy in a protected spot. All scilla increase both from bulbs and from seed. One variety of Scilla is now called Ëndymion. It ranges from the 8 inch E. non-scriptus (which also comes in pink or white and tolerates light shade) to E. hispanica that grows up to 2 feet tall.

Allium varieties (or ornamental garlic) grow from 6 inches up to 4 feet tall and have bloom heads ranging from 1 to 9 inches in diameter. The colors are "pinkish" violet through rosy purple, white, yellow and blue. They need sun and good drainage. They grow from bulbs or creeping rootstocks. Most self-sow vigorously, so seed heads should be removed. They last well in the garden and as cut flowers. The dried seed heads are ornamental in arrangements.

Anemones and Ranunculus grow from tubers and need a few degrees of protection to survive in Albuquerque and should be soaked before planting. They need to be dry in summer so they won't rot. Plant anemones on edge if you can't tell which end is up.

Eremurus (Fox-tail lily) grows from spider-like tuberous roots that are very brittle and are difficult to transplant. The flower spike may reach from 3 to 7 feet above yucca-like foliage and have small yellow, pink or white flowers. Eremurus need a sunny, well-drained spot.

Fritillaria imperialis look striking in the garden with their 3 to 4 feet stalks topped with clusters of orange or yellow bells. They like the excellent drainage of a slope with ample humus. The foliage has a "skunky" odor. F. meleagris is much more delicate with 1 to 3 checkered purple or white bells on a 1 foot wiry stem. Fritillaria (Crown Imperial) bulbs should be planted on their sides because the bulb may rot if water collects in the cup of the bulb. They also need humus, require some shade and more moisture. Other Fritillaria are being offered in catalogs and some may prove successful here.

Galanthus species (Snow drops) require some shade and more constant moisture than most bulbs while they are dormant. They can be transplanted while still in leaf. Snowflakes (Leucojum) have white flowers in the spring and are reputedly better for warm climate than snowdrops but to my eye are too floppy, have more foliage than flowers and hang around too long before going dormant.

Galtonia candicans (Summer Hyacinths) bloom in light shade with 2 to 4 foot stems topped with loose spikes of white bells.

Ipheion uniflorum (Spring Starflower) is very drought tolerant and its dormant bulbs thrive in summer heat. A single sky blue flower arises on each 6-inch stem, and each bulb produces several stems. The onion-scented leaves are gray-blue and appear in the fall and persist until after blooming. If the leaves are tattered by spring, pull off the damaged ones. They increase prolifically by both bulb and seed.

Iris 

The Iris family has a large number of species among which there are bulbous ones. Dutch, English, Spanish, Reticulata, and Danfordii. The rhizomatous ones include the tall bearded (Iris Germanica), Siberian, Arils, aril breds, and spurias. The culture of these will vary so a good resource for them should be consulted and can be found on the Internet.

Iris reticulata needs a warm, sunny, well-drained site. They bloom early and have the scent of violets. The foliage may attain 18 inches, but it is generally sparse. I. Danfordiae resembles "retics", but it is yellow. When they are well sited, they will re-bloom and multiply and not just shatter into tiny cormlets. They seem to need lots of heat in the soil when they are dormant.

Dutch iris need excellent drainage, sun and a dry summer. The foliage may appear in the fall and suffer winter damage. The dead tips can be trimmed for neatness sake in the spring.

Zantedeschia aethiopica or Calla lily is hardy in many Albuquerque gardens. The ones with white spotted arrow-sha0ed leaves are especially attractive and may be planted in the same area as Arum italicum for a year round display of interesting leaves in semi-shade.

Zephyranthes (Rain lily or Fairy Lily) have nearly evergreen, grassy leaves. They surprise us with small crocus-like flowers on 6 to 8 inch stems in August. Z. candida (white) is the most hardy, but pink ones may survive with protection.

Lilies

Lilies will bloom in June with a range of colors and grow up to 5 feet tall. Asiatic hybrids do better here than the Oriental hybrids. (Remember "Ä" for Albuquerque). The bulbs are never truly dormant, so they must not bake. They need shade at the roots and mulch with sun to half sun on the foliage and flowers.

 Summer Blooming Bulbs.

Amercrinum

Most of the summer blooming bulbs should be planted after the soil has warmed although some may be hardy such as some Gladioli, some Canna in some locations, Calla in some locations, Galtonia candicans, Alliums, Lilies and Hemerocallis (Daylilies). Other more tender bulbs are Crocossmia, Dahlias, Tuberoses, Tigridia, Acidanthera, Tuberous Begonias, and Caladium. All these should be dug after frost, stored in cool, not too dry locations. Tuberous begonias and Caladium that is grown for the decorative colorful leaves are both quite tender and should be planted in shade.

Fall Blooming Bulbs

Hardy fall blooming bulbs include Colchicum (aka autumn crocus) that sends up large leaves in spring, Crocus (the true autumn crocus), C. sativus (saffron crocus), Cyclamen hederifolium (C. neopolitanum), Sternbergia lutea (needs a warm spot, has green leaves in winter). Lycoris squamageria (Naked Lady Lily), and Lycoris radiata (spider lily) have green leaves in the winter. .

    Arum italicum is grown for its white, marbled, arrow-shaped leaves that appear in the fall and remain through the winter in a semi-shaded damp area. The green, calla-like spathe appears in the spring and may be followed by red berries.

    Fall-blooming crocus as well as Colchicum (Autumn Crocus) are happy here. However the latter have large pleated leaves that appear in the spring, in contrast to the white-lined, grassy leaves of Crocus that may appear with the flowers or in the spring. All parts of colchicum are poisonous. Most have 6-petaled lavender flowers, but there are also white and double varieties. 

    Cyclamen hederifolium is 6 inches tall with 3/4-inch fragrant flowers and has mottled leaves in the winter. Cyclamens prefer a cool shady place, but too much moisture will rot the dormant tuber. The leaves, which resemble English ivy, appear with the flowers in September and make an attractive ground cover until May. Mark the site so as not to dig into dormant tubers.  They will re-seed and bloom in 3 to 5 years.

    Sternbergia lutea resembles a yellow crocus on an 8 to 10 inch stem rising from shiny green leaves that remain all winter in a warm sunny spot.

    Lycoris squamageria (Naked Lady or Magic Lily) bloom in August with clusters of pink/lilac flowers on 2-foot stems. In old gardens the daffodil-like leaves may cause concern when they appear in the spring with no flowers. But they bloom later "Naked". They tolerate a little shade and require more winter cold than Spider Lily (l. radiata) that blooms in September with coral-colored flowers. Both develop white-lined foliage that persists through the winter. Overhead sprinkling damages the flowers. Other Lycoris species are more tender but may be grown under glass.

SS = Self Sows
DT = Drought Tolerant
Color Code: B=Blue, Br=Brown, R=Red, Y=Yellow, P=Pink, Or=Orange, Wh=White, Pu=Purple, Lv=Lavender, Mg=Magenta, Gr=Green
Season Code:  ES=Early Spring, S=Spring, Su=Summer, EF=Early Fall, F=Fall, W=Winter

(Very similar charts to this appear in the 2002 Master Gardener Manual which were prepared by Carol Adams. However, since we do not have access to the CD for that manual and in fact had no knowledge of those chart's existence or contents, the charts for Annuals, Bulbs, and Perennials were independently prepared for this web site by Ellen Reed (author) and Ruth Bronson (editor) from materials in the 2001 Manual.)

 02/05/2003

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