Spring is in the air and your bulbs are just starting to show some foliage as they get started on providing you with a dazzling display of color and form. But wait. What have we here? You see flower bulbs coming to the surface and there is still a danger of frost and freezing conditions. Heaving of bulbs is common and may be the result of weather conditions, soil porosity, planting depth, or just the variety of plant bulb. You need to take action to protect the bulbs from cold and animals and learn how to stop bulbs from coming out of the ground.
One reason you may see bulbs coming out of the ground is improper site condition. Soil for bulbs needs to be rich and organic, well worked, and free draining. Bulbs will rot in boggy soil, and they have difficulty growing up through hard pan or heavy clay.
Amend the bed with plenty of organic matter to increase porosity or the area will get waterlogged, freeze, and force the bulbs up out of the soil as it thaws and refreezes. Soil that doesn’t drain will also get muddy and bulbs can literally float up to the surface of the ground and get trapped there as the water recedes.
Winter is characterized by wicked weather. In many regions, it is comprised of freezing rain, snow, heavy rain, and thick icy rime over the ground. Periods of thawing are common as the winter nears its end, but a freeze is likely to follow.
This contractive action actually moves the soil and, therefore, pushes the bulbs up to the surface if they are not planted deeply enough. The process is called frost heaving. The proper depth for planting varies by bulb but on average, install them three times the diameter of the bulb deep in the soil.
Winter conditions will also tend to erode the soil, so planting depth becomes especially crucial to reduce the chance of bulbs coming out of the ground.
Looking around your flower bed you see a plant bulb is surfacing. It’s not time to panic if the bulb is a certain variety.
Nerine bulbs, for example, tend to collect at the top of the soil. Flower bulbs that naturalize, such as tulips and daffodils, will produce clusters of bulblets that can push to the surface of the soil. Snowdrops also naturalize and produce thick groups of the plant with their bulbs often just at the surface of the soil. For the most part, this isn’t a big deal. Just dig the bulb up and gently plant it deeper.
In urban or rural areas, one of the most common reasons for bulbs to be exposed is due to varmints. Squirrels are the primary culprits, but even the neighborhood dog might be digging them up. Again, if the bulbs are undamaged, simply replant them as you find them to protect the bulb from other influences.
It is normal to see what looks like a plant bulb surfacing if it is a root crop. Onions rise to the surface, radishes push up and expose their ruby skin, and even rutabagas will surface to expose themselves to the tender ministrations of the garden slugs. Proper soil condition is again a cause of this, so remember to work your soil until it is airy and fluffy before planting any root vegetables.
There is no perfect moment, calendar-wise, for planting bulbs. The ideal time to plant your spring bulbs depends on where you live and seasonal weather conditions.
To break dormancy and bloom, most of the more common spring-blooming bulbs (like tulips, daffodils, hyacinths, and crocus) must be exposed to temperatures of 40° Fahrenheit (or colder) for at least 12-14 weeks. Exposing bulbs to these cold temperatures stimulates them to turns on flower formation and initiates root growth. Most spring-flowering bulbs must be planted in soil for several weeks before the ground freezes for their root systems to develop.
Planting bulbs too early in the fall can be detrimental because the bulbs could start to sprout. Sending up foliage too early depletes a bulb's energy that it needs to get through the winter and bloom in spring. So, if your area is experiencing a long summer and temperatures are still quite warm at the beginning of fall, hold off planting until temperatures begin to cool down.
Here are the general rules of thumb for planting spring-blooming bulbs:
Listening to some gardeners talk about it, you would think that a genuinely "perennial" tulip is some kind of holy grail. The dream of a tulip that comes back and multiplies has inspired and then eluded many gardeners. Any skepticism you may have is why I hesitate to make the following claim, but here it is: Wild or species tulips are perennials. Under optimal conditions, they will come back year after year and usually increase in numbers. In many cases, gardeners find themselves pulling out some that have strayed too far.
Species tulips are the wildflowers of the tulip family. The much larger and more extravagant hybrid tulips, bred largely by Dutch horticulturists, are their fancier descendents.
Hardy wild tulips require less work. They are less vulnerable to stormy spring weather, and their generally short stems don't bend in strong winds.
Another appealing feature of species tulips is how they flower. Their flowers usually remain closed through the morning or on cloudy days, showing only the outside color of the petals. When warmed by the sun, they open to reveal another petal color on the inside. It's like having two different flowers in the same space at once. What a treat!
Species tulips propagate quickest given full sun but tolerate partial shade. The only cultural feature they are persnickety about is well-drained soil. Sandy soil is best. If your garden lacks good drainage, work fully composted pine or fir bark or a similar organic amendment into the soil.
When and How to Plant
The best tulip-planting time depends on where you live. Ideally, wait until the soil temperature is below 60 degrees F. As a general guide, plant in September through early October if you live in USDA Hardiness Zones 4 or 5 October to early November in zones 6 or 7 November to early December in zones 8 and 9 and late December to early January in zone 10 (after refrigerating the bulbs for 8 to 10 weeks).
Set the bulbs in a planting bed or in separate planting holes with their roots or basal plate downward. Plant bulbs 4 to 6 inches below the surface, or three to four times their height. Space the bulbs of most species tulips 2 to 6 inches apart, or three times their width, following the supplier's instructions. Water the bulbs right away to initiate growth. Mulch after planting to help keep soil cool in mild winter areas mulch after soil freezes in cold-winter areas.
If you live in the South (or mild-winter areas of the West), plant "mild-winter" tulips that thrive in zones 8 through 10: the lady tulip (T. clusiana), the Candia tulip (T. saxatilis), and the Florentine tulip (T. sylvestris). These tulips do not need chilling before planting in these regions. In areas like Tallahassee, Houston, or San Diego, buy these three types of species tulips in the fall, plant them in a cool, shaded location, and forget them. They'll flower in spring and likely for many springs to come.
Most species tulips naturalize-when unaffected by rodents-via seeds, underground stems called stolons, or daughter bulbs. The new plants are usually identical to the parent plant, but beds of seed-grown plants may produce some flower-color variation.
Encourage the bulbs' multiplying tendencies by leaving faded flower heads attached so that seeds can mature and spread. Don't remove leaves until they begin to turn yellow and fall over. Bulb plants use the extra time in leaf to continue photosynthesis and store nutrients for the next year.
Every fall, apply 4 to 5 pounds of the 9-9-6 fertilizer called Holland Bulb Booster per 100 square feet over the tulip bed. If you prefer organic plant food, I recommend Bulb Mate, a 5-10-12 mix of cricket manure, rock phosphate, bonemeal, blood meal, dolomitic limestone, granite meal, and compost. Apply 8 pounds of it per 100 square feet.
Water the growing plants in spring if the garden doesn't receive about 1/2 inch of rain weekly. Species tulips are dormant in the summer and prefer dry soil then, but most kinds adapt to garden situations (the exceptions are noted below).
Insects or Other Pests
If you have rodents such as voles or gophers (or what my husband and I call "underground bulb monsters") in your garden, adding a handful of sharp gravel to the hole on the tulip bulb will discourage them from eating it. Don't mulch where rodents are a problem, because they love to nest in mulches. Wire or fabric baskets protect bulbs from rodents, and repellents are available that help deter these pests. Of course, a good cat or two is the best control of all.
You can force species tulips to bloom indoors. In cold-winter climates, pot the bulbs and cover them with about 8 inches of mulch, or store them in an unheated, ventilated basement or garage for about four months beginning in the fall. Move them to a sunny place when shoots appear. In warm climates, store the pots in a cool location, but check for root growth after 8 to 10 weeks, then move them to a warmer location.
Several of these wild tulips have been hard to find in the past, and some still are. All are available via mail-order suppliers, and most garden centers also stock species tulips in the fall.
Most commercially available species tulip bulbs are nursery-propagated and grown, but check with your supplier to be sure they were not collected from the wild.
Favorite Species Tulips and Their Hybrids
Native to areas ranging from Europe to central Asia and China, the following 22 species of wild tulips are charming and widely available. All are, technically, "other species." Tulipa fosteriana, T. greigii, and T. kaufmanniana are not commercially available as wild species but are categorized as hybrids with the characteristics of wild tulips.
Bloom season isbased on typical zone-6 bloom times: "early" (March to April), "midseason" mid- to late April, and "late" (April to late May). South of zone 6, blooms come early north of zone 6, they come later.
Recommended zones are guidelines, not absolutes. Exploit microclimates and provide good growing conditions to promote growth.
T. albertii. Midseason bloom. Height is 10 to 12 inches. Zones 6 through 8.
T. bakeri 'Lilac Wonder'. Blooms early. Height is 6 to 8 inches. Zones 5 through 9.
T. batalinii hybrids. All bloom midseason and grow 4 to 6 inches high. Best varieties are: 'Apricot Jewel'--see photo-its leaves form a lovely rosette 'Bright Gem'--a fragrant flower of soft sulfur yellow with an orange-sherbet flush 'Red Gem'--red petals with an apricot glow and 'Yellow Jewel'--pale yellow flowers with a dusting of rose, and prostrate leaves. Zones 4 through 8.
T. biflora. Blooms early. Fragrant. Height is 4 inches. Each bulb produces one to five small flowers that open wide. Zones 4 through 8.
T. clusiana hybrids. Sometimes called lady tulips, these varieties bloom in midseason on 8- to 10-inch stems. Varieties are: 'Lady Jane'--alternating red petals and white petal-like sepals suggest a candy cane. It is a readily available strong grower 'Cynthia' (similar to T. clusiana chrysantha)--red petals with chartreuse edges, a purple base, and soft green anthers 'Tubergen's Gem'. Zones 4 through 10.
T. eichleri (also known as T. undulatifolia). This early bloomer reaches 10 to 12 inches tall and multiplies rapidly. Zones 4 through 8.
T. hageri. Midseason blooms grow atop 5- to 6-inch stems. 'Splendens' grows 8 inches tall and produces three to five coppery bronze flowers per stem. Zones 4 through 9.
T. humilis (also known as T. pulchella). Small, crocus-shaped flowers are normally pale pink with a yellow center, but some are dark purple with black or purple bases. Very early bloomer. One, but sometimes three flowers, to a stem. Height is 4 inches.
Varieties include: T. h. albocaerulea-occulata--white with a deep steel-blue base 'Eastern Star'--magenta-rose with a bronze-green flame outside and a canary yellow base 'Lilliput'--red with a violet base and more than one flower per stem 'Odalisque'--rosy-red outer petals with a silvery glow, striped green at the base, and the inner petals are beet-purple with a large yellow base 'Persian Pearl' and 'Violacea'--pointed purplish rose petals with green-tinged lower part and a yellow basal blotch margined with blue or greenish black. Zones 4 through 9.
T. kolpakowskiana. Yellow flowers streaked with red come one to three per stem in mid- to late season on 6- to 8- inch stems. Wavy-edged leaves lie nearly flat against the ground. Zones 5 through 8.
T. linifolia. Blooms midseason on 4- to 6-inch stems. Zones 5 through 8.
T. neustruevae. Blooms early. Height is about 4 inches. Zones 4 through 8.
T. orphanidea. Sometimes called the Spartan tulip, blooms on 8- to 10-inch stems in early spring. Yellow-flowered T. orphanidea 'Flava' is long-blooming. Spreads by stolons. Zones 5 through 9.
T. polychroma. Five blooms per stem appear early in the season. Height is about 4 inches. Zones 5 through 8.
T. praestans. Up to four flowers on 12- to 16-inch stems bloom in midseason. Orange-red 'Fusilier' is shorter but offers up to five flowers per stem. 'Unicum' also has five flowers per stem, but is slightly less cold hardy. 'Zwanenburg' has slightly larger and darker flowers compared to 'Fusilier', but it may be difficult to find. Zones 4 through 9.
T. saxatilis. Also called the Candia tulip, it grows 6 to 8 inches high. In sunlight, flowers open early in the season into an elegant star shape. This species is excellent for mild-winter climates and will multiply rapidly farther south than other tulips. Spreads by fat, white stolons. Zones 5 through 10.
T. sylvestris. Also called the Florentine tulip, the sweet, musk-scented flowers come one or two per 10- to 12-inch stem in late spring. Spreads via stolons. Zones 4 through 9.
T. tarda (also known as T. dasystemon tarda). Fragrant flowers bloom early. Each 3- to 4-inch stem produces up to six flowers. The plant multiplies rapidly. Zones 4 through 8.
T. turkestanica. Up to seven petals bloom on 3- to 10-inch stems. The species is variable, however. Some have black centers, and some have red centers. Blooms early and multiplies readily. Zones 4 through 8.
T. urumiensis. Three to five flowers per stem. Blooms early to midseason. Height is 4 inches. Zones 4 through 8.
T. vvedenskyi 'Tangerine Beauty'. Petals open wide, bending backward in bright sun. Blooms mid- to late season. Height is 8 to 10 inches. Zones 5 through 8.
T. whittallii. One of my favorites and an amazing naturalizer, this tulip blooms in midseason. Height is 8 to 10 inches. Zones 4 through 8.
T. wilsoniana (also known as T. montana). Flowers open wide in full sun, and with the central yellow anthers, the effect is striking. Blooms late. Height is 4 to 6 inches. Zones 5 through 8.
When you look at the many vibrant members of the iris family, it’s not hard to see why Swedish botanist Carl Linnaeus named the group after the Greek goddess of rainbows, Iris. Members of the Iridaceae family, irises — with about 80 genera and 1,500 species — are truly a varied group, not just in the assortment of colors in which they come, but in the types of habitats they prefer, which range from desert conditions to swamps. You can find members of this diverse group in Europe, the Middle East and Northern Africa, and across North America. Growing from rhizomes or bulbs, these lovely flowers reach a variety of heights and bloom in every season, too.
Rhizomatous irises which include the popular bearded iris , are typically planted with the top of the rhizome poking out just above soil level. An easy way to do this is to dig two shallow trenches with a ridge between them. Place the rhizome atop the ridge and spread its roots into the trenches. Fill the trenches with soil, then top-dress with a low- nitrogen fertilizer (high-nitrogen fertilizers will “burn” the rhizome). After the initial planting, fertilize the rhizomes each spring. Water often: Bearded irises prefer moist, well-drained soil. Do not mulch bearded irises during their growing season, since the mulch can harbor disease and pests that will infect the rhizome.
Choosing an iris for your garden
Plant beardless irises, which are also rhizomatous, using this same technique, but set the entire rhizome beneath the soil’s surface. Unlike their bearded cousins, many beardless iris varieties (including Japanese , Siberian , and Louisiana irises) prefer wet conditions, so they benefit from moisture-retentive mulch when they are growing. You should, however, mulch all iris varieties in winter, because it will prevent frost heaving.
Definition : Frost heaving is the expansion and contraction of the soil’s surface due to the freezing and thawing of moisture within the soil.
Bulbous irises include the popular Dutch iris, plus English and Spanish irises. Plant bulbs in a light, well- drained soil mix. If you have heavy clay soil, add some coarse sand and humus. Plant the bulbs 3-4″ deep and 4″ apart. After the plants have flowered, feed them with a high-phosphorus fertilizer to encourage bulb growth.
Iris have six petals. The three larger petals, which generally extend below the flower, head, are called falls. this is where the “beards” of bearded iris, or the “crests” of a crested iris, are found. The “shoulders” of the falls are called hafts. The style arms are smaller petallike parts over the falls these have the stigmas (where pollen is deposited).
The other three petals are often smaller, and usually extend above or to the side of the flower head these are called standards.
Over time, iris beds, whether planted with rhizomes or bulbs, can become crowded and blooms may suffer. You can get your plants back to blooming beautifully by dividing them. After your bearded iris has bloomed, carefully lift the entire clump with a garden fork. Using a sharp knife, cut apart the new, younger sections from the original center rhizomes, then replant, either in the same spot, a new spot, or both. You may want to let the rhizomes dry in the sun for a day before replanting.
Divide bulbous irises in early autumn after the plants have finished blooming, but while they still have foliage. Dig them up gently (any cuts or bruises can invite diseases) and, with your hands, carefully pull the bulbs apart. If the bulbs do not separate easily, stop and wait another year or so, then try again. Once separated, the bulbs can be replanted wherever you’d like them to go.
The Iris family: More than meets the eye
Bearded: Plants have sword-shaped, usually broad leaves and simple or branched flower stems bears multiple flowers, each with a prominent “beard” of white or colored hairs in the center of each fall (lower petal). The most common of the irises, bearded varieties are classified according to height and are planted so the rhizome pokes out above soil level.
Beardless: Do not have “beards” rhizomes are planted just below ground level.
Siberian : Blue, purple, white, yellow, pink, or deep red flowers with large falls and smaller standards.
Laevigatae (a.k.a water irises): Simple stems bears blue, pink, red, purple, white, or yellow flowers.
Louisiana: Often have zigzag stems that bear flowers in large range of colors prefers damp conditions.
Unguiculares: Evergreen, almost stemless plants bear blue, violet, lavender-pink, or white flowers from autumn to spring develops from a mass of rhizomes aboveground.
Crested (a.k.a. Evansia irises): Relatively flat flowers in shades of blue, violet, or white that have a crest or ridge on each fall instead of a beard.
How does your iris grow?
Rhizome: A swollen length of underground stem that bears roots and leaves. A rhizome grows horizontally and forms roots on its underside while leaves sprout from the top. Buds form at intervals along the structure.
Bulb: Formed from the plant stem and leaves. The bottom of a bulb is made up of a small disk called the basal plate, which is a compressed stem. Roots grow from the bottom of the plate. Layers of scalelike leaf bases filled with food sit on the plate and sorround a bud that will become the next year’s flower.
Pests and diseases
Although most varieties are deer resistant, irises can attract a significant number of pests, including aphids, iris borers, iris weevils, slugs and snails, thrips, verbena bud moths, and whitefies. The most significant of these pests, however, are iris borers, which chew on leaves and bore into the plant stems, leaving the plant wide open for soft rot, a foul-smelling bacterial infection that kills more plants than plants borers themselves actually do. The best way to avoid an infestation of borers is to keep the area around your irises clear of debris. If you notice any signs of infestation, dig up your plants and cut off and dispose of any infected parts, comb the soil for additional borers, and enlist the help of beneficial nematodes, which will destroy these pests.
How to grow?
Beardless flowers with deciduous leaves appear from late winter to midsummer.
Dutch: Slender, graceful flowers in a variety of blues and yellows, with broad, sword-shaped foliage.
Dwarf: Flowers are yellow, blue, white, or reddish violet bulbs are covered with netted tunics.
Juno (Rare): Plants have flat or channeled leaves and grow from fleshy-rooted bulbs.
Did you know?