TULIP CLASSIFICATION

ORIGIN
Members of the Liliaceae family

Common garden tulips have been developed over three centuries of breeding, predominantly from the species "Tulipa gesneriana"

Tulipa gesneriana has a papery slightly hairy surface to the bulb. Its hybrids are generally taller late flowering varieties have been bred mainly from this species.

• Originated in Asia from Turkey and southern Russia to South West China and Kashmir.

 
VARIETIES
Tulips are classified into fifteen groups based upon botanical origin, time of flowering and flower shape. There are over 4,000 registered cultivars.
The fifteen groups are outlined below:

1.  Early Single Tulips
• 25-60cm tall
• single flowers
• flower petals sometimes flatten out in full sun
• flower early to mid spring in cool temperate climates

2.  Early Double Tulips
• 25-40cm tall
• double flowers, 6-10cm diameter
• flower early to mid spring in cold temperate climates

3.  Triumph Tulips
• to 60cm tall
• sturdy flowers resist bad weather
• conical shape flowers
• flower early to late spring in cold temperate climates

4.  Darwin Hybrids
• flower mid to late spring
• large and showy flowers

5.  Late Single Tulips
(Sometimes called Darwin tulips; not Darwin hybrids)
• 50 to 75cm tall
• petals are often pointed
• flower late spring or in cold areas, even early summer

6.  Lily Flowered Tulips
• petals are curved outwards and pointed
• flowers are delicate
• flower late spring in cold temperate climates

7.  Fringed Tulips
• 60-80cm tall
• flower petals have a fringed edge

8.  Viridiflora Tulips
• to 30cm tall
• petals have some shades of green in them

9.  Rembrandt Tulips
• petals have streaks of colour (caused by a virus)
• late flowering
• 40-70cm tall

10. Parrot Tulips
• 45-60cm tall
• petals are twisted and have a frilly or fringed edge
• late flowering

11. Late Double Tulips
(Also known as paeony tulips)
• to 60cm tall
• double, showy flowers
• delicate flowers but sturdy stalks
• flower mid to late spring in cold temperate climates

12. Kauffmanniana Tulips
(Bred mainly from Tulipa kaufmanniana)
• 6cm diameter flowers similar to water lily
• 10-25cm tall
• flowers usually bicoloured

13. Fosteriana Tulips
• to 45cm tall
• very large and bright coloured flowers

14. Greigii Tulips
• 20-40cm tall
• foliage usually with streaks of colour and an attractive twisted or wavy shape
• flowers mid to late spring in cold temperate climates

 
15. Botanical Species
• characteristics vary greatly
• some are commonly grown, but not usually as cut flowers

Varieties grown commercially for cut flowers can be classified into three groups:
a. Darwin hybrids
b. Triumph Tulips
c. Darwin (or Single Late) Tulips -produced by crossing with "Tulipa forrestiana"
   and/or "Tulipa greigii"

TULIP CULTURE SUMMARISED
Planting
• Usually plant 10-20cm deep (plant deeper in sandier soils or warmer localities and shallower in heavier soils or colder areas).
• Plant when ground temperatures are at or lower than 14 degrees Celsius and are falling.
• Plant in late autumn in snow prone areas.
• Plant in winter in milder areas (earlier flowering varieties have a better chance of performing in milder climates).
• Select large, firm, healthy bulbs for planting.
• Only buy bulbs from a reputable nursery to avoid bringing disease into your garden.

Position
• in heavy soils, grow in raised beds
• plant in full sun (in shade bulbs will deteriorate over several seasons)
• grow well in pots or tubs (plant about 15cm deep in pots)
• smaller types grow well in rockeries

Soil
• light, fertile, well drained soil is best
• ph 6.0

Weeds
Commercial crops often are treated with a pre emergent herbicide after cultivation and forming the soil into mounded rows.

Nutrition
Dig in manure or blood and bone some time before planting

Water
• water regularly but not heavily
• soil must remain moist but not saturated
• in pots only water in the morning

Removing Spent Flowers
If growing as a garden plant, remove faded flowers as rotting stems can spread infection to other parts of the plant.

Lifting
In mild areas best to be lifted annually, after flowering when foliage is dying back
In snow prone, cold climates, they can be left in the ground for several seasons provided drainage is reasonable. Species tulips normally only need lifting - every two to three seasons.
After lifting, clean the bulbs (and possibly dust with naphthalene dust) before storing in a cool, dry well ventilated place. Bulbs should be kept at a temperature no higher than 20 degrees Celsius over summer.

 

PROPAGATION
Bulbs naturally reproduce small bulbs (offsets) each year. The smallest bulbs may take a couple of years to produce decent flowers. They should be separated off and grown away from the crop or display plants until they reach a good size. Rapid natural multiplication only occurs when cultural conditions are close to ideal. Offsets from tulips need to be planted deeply to initiate flowering (deep planting (around 20cm) is better then planting too shallow. Offsets can be encouraged by cutting small notches into the basal plate.

Seeds germinate easily and fast if planted fresh, as soon as they are ripe, normally in autumn. They need a period of frost to germinate evenly. Seedlings can take 4 to 6 years to produce flowers. Seed is only used for breeding, or for growing varieties which do not propagate readily from natural multiplication of bulbs.

Commercial growers also use tissue culture to produce new plants.

PESTS AND DISEASES
Law in Relation to Chemical Use
Manufacturers, wholesalers, retailers, advisers, farmers, veterinarians, ground and aerial spray applicators and householders should all be aware of regulations concerning the spraying, storage, transportation and disposal of chemicals.  Ignorance is no longer an excuse!
Each country, state, or region may enforce a different Act to control chemical use. If you intend to use chemicals it is your responsibility to become acquainted with your local laws and relevant Acts. Ignorance of the law will not prevent you from being prosecuted for misusing chemicals.

*The status of individual chemicals is constantly being reviewed world-wide: any chemicals listed here may have a different status or be governed by different restrictions or laws in your region. In some cases chemicals permissible in one country will be strictly prohibited in another.

You should be aware of the regulations in your country as well as those for your state/region:

Material Safety Data Sheets (MSDS), Safety Data Sheets (SDS) or Pesticide Information Sheets are available for all manufactured chemicals. You should ensure that you have a copy of each sheet for every chemical that you have in use or storage.  Use, storage and transportation of the chemical must comply with any restrictions indicated on these sheets, and the local law applicable to the chemical.

Tulips - Pests and Disease Problems
Though relatively free of pest and disease problems, there are some problems which can have a devastating affect on a crop.

Fungal diseases, particularly botrytis mould can be a problem.
Fungal problems are more likely to occur after cold weather, hail or wind or some other event which leaves the plant a little weaker or damaged, hence more susceptible.
Spray Benlate early in the season to control botrytis (grey mould).

Aphids (ie. green fly) can be a problem, particularly if it transmits virus from plant to plant (see below).
This aphid also attacks iris, freesia, gladiolus and crocus. It is grey with a waxy appearance and clusters under bulb coats. It may also infest aboveground parts.

Control: if aphids are present before planting dip bulbs in Diazinon.

Slugs and snails can sometimes be a problem and can be found in moist areas or places sheltered from the sun and wind.
Control: Spread fresh saw-dust or rice hulls on the ground, or plant prostrate rosemary or wormwood to deter the snails slightly. Chemical snail pellets or powder work, but pellets in particular can be dangerous to pets. Dust with tobacco leaves, or control by spraying with Malathion, Carbaryl or Rogor.

VIRUS diseases will often affect a tulip causing the pure colour to develop streaks or stripes.
 
The virus is usually carried to the bulb by aphis, hence it is important to control aphis with an insecticide as soon as it is detected. Virus affected bulbs are weaker and more susceptible to problems which might affect their performance. Once affected, a bulb never recovers.
 
Bulb mite is a tiny animal which can attack the bulbs sometimes leading to rots developing.
Foliage on affected bulbs will turn pale. Infection usually builds over a period of years.

Control: Discard all bulbs in which heavy infestation in evident. Avoid planting clean bulbs in ground previously infested unless the soil has been steam-pasteurized. Bulbs may be freed of mites by dipping them in hot water at 122 deg F for a few minutes. (Hot water treatments cannot be used safely if the roots have started to develop).

Blight or Fire Blight; the leaves become flecked with small brown spots; flowers also are attacked. The spots are most noticeable on light-coloured varieties. When the bulb is attacked the whole plant becomes dwarfed and the flower is blasted. The rot, as it develops on the leaves and flower stalks may cause a grey discolouration bordered by brown margins. In moist weather the diseased parts may be covered with a grey mould which produces large numbers of conidia; these are spread by air currents and other agents to other plants.
Control: a careful inspection should be made before planting. Remove infected plants, taking care not to spread spores. Good protection can be achieved by frequent applications of Botran.

NOTE: crop rotation can be important to controlling disease in tulips.

CONTROLLING FLOWERING
Darwin (ie. late single) or single late tulips are not as responsive to storage at low temperatures or storing for longer periods of time. These are stored at 8 degrees Celsius for 6 to 8 weeks then planted in a cool soil.
Darwin hybrids are stored at 2 degrees Celsius for at least 10 weeks then planted straight into a greenhouse to give flowers six weeks later.

Temperature
• If growing in milder areas, bulbs need to be kept at a maximum of 4 to 7 degrees Celsius for at least 2 months from autumn to early winter before planting.
• In milder climates, bulbs can be put in the "crisper" section of a refrigerator for the eight weeks prior to planting, to improve their chance of performing. (Plants treated this way may flower in much warmer than usual climates, but the bulbs will deteriorate in such climates and probably will not flower the next season)
• Darwin hybrids need more cold during dormancy than Triumph or Darwin cultivars. Tulips are not suited to hot climates

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