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Growing Spring Bulbs

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Included are: Tulips, Dutch Iris, Narcissus (Daffodils and Jonquils), Crocus, Anemones, Ranunculas, Freesias, Hyacinths, Liliums, Zantedeschia (Calla Lilies)

Tulips

  

Tulips enjoy well drained soil with a pH above 6.  Therefore wetter soils can benefit from being moulded into raised beds and the pH can be adjusted by the addition of lime or dolomite, if necessary.  The best fertiliser is a combination of blood and bone and a little complete fertiliser mixed into the soil prior to planting.  Tulips also like a cool Winter, so we achieve this in Australia’s milder climates by refrigerating the bulbs (see below).  Plant tulips at the end of April or early May when the soil has cooled to below 14 degrees.  Cover them with 15-20cm of soil to insulate them from the sun’s heat and plant 7-20cm apart.  Most bulbs prefer a sunny or half shade situation.  Unhealthy bulbs should be removed to protect the main planting.  While your bulbs are growing keep them free from aphids and do not over-water during the winter.  After flowering, water them well so that they will produce nice bulbs for the following year.  These new bulbs can be lifted when the foliage yellows, and stored in a net bag in a well ventilated area away from direct sunlight.  The ideal temperature is around 20 degrees, but in hot climates this may be hard to achieve.  Sustained very high temperatures will kill the flower developing in the bulb.  Many people ask if they can leave tulip bulbs in the ground.  Unfortunately, there is no easy answer to this question.  In Tasmania, and some parts of mainland Australia with cool summers, it appears possible to leave bulbs unlifted for 2-3 years if the area in which they are growing is dry during the summer.  We suggest only single late and Darwin hybrid varieties for this, however we are unable to recommend this treatment.

Cut tulip flowers while they are nicely coloured buds.  Arranging tulips is a joy – because they do it themselves.  A clean vase and fresh water and in they go “Hey Presto” an elegant display.  The flower buds will intensify in colour and open, and even grow further in length.

 

Tulip Bulbs in Pots

A number of our varieties are very suitable for potting (look for potting symbol).  A bulb potting mix can be purchased from Bunnings.  Bulbs in pots require more care than those grown in the garden since they can easily dry out.  For best results with potted tulips, use a large pot or tub where the bulbs have plenty of room to grow and survive for a few extra days if you forget to water them.  Potted bulbs should be kept outside, except during flowering when they may be taken indoors.  The critical time for care of the bulbs is after flowering.  During this time the bulbs make their growth for the next year and if the pot dries out during this period the bulbs may not grow to flowering size.

 

Growing Tulips in warmer climates

Yes, tulips do grow better in cooler climates but you can share the pleasure in warmer climates too!

Imagine a beautiful tub of colour to enjoy in late winter in Sydney or Brisbane that will be the envy of all of your neighbours. It will probably not be possible for you to get flowers from the bulbs in the next year but the 2-3 weeks of pleasure that you obtain from these stunning flowers will be a good value purchase from your garden/flower/wine/lotto budget.

Just follow these simple steps:

1. Select your bulbs from the medium and tall growing bulbs, not the rockery types. The safest ones to grow are those marked for warm climates.

2. Do not take delivery of your tulips until at least March (this protects the bulbs from the worst of your summer heat)

3. Between mid-March and early April put the bulbs in the crisper of your fridge for 6-8 weeks until late May

4. Plant the bulbs in a large pot/tub with up to 10 bulbs for a 20 cm pot, 20 bulbs for a 30 cm pot, 35 bulbs for a 40 cm pot and up to 50 bulbs for a 50 cm pot. (You can under-plant with violas and reduce the number of tulips.) Use a good quality potting mix from your nursery.

5. Place the tub in the coldest place in your garden, with absolutely no sun, until the shoots are about 5 cm high.

6. Move the tub to your preferred display position, full sun or shade, and enjoy the spectacle of the rapid growth and flowering of the tulips.

If you wish to try and flower the bulbs for a second year, use only bulbs marked in our catalogue as suitable for warm areas.

Re-Using Bulbs in Warmer Climates (Year on Year Growing)

Bulb growers in warm climates (e.g. Perth, Brisbane, Sydney) face some difficult issues with respect to re-using tulips for second and subsequent years.

These issues relate to:

  • The short period for new bulb growth following flowering
  • The very long period of senescence
  • Summer heat

1. The short period for new bulb growth following flowering

Tulips and Dutch iris differ from many bulbs in that the bulbs produced after each growing period are new bulbs. The bulb that is planted is used up producing the new leaves and flowers and new bulbs that were embryonic in the planted bulb grow to replace the planted bulb. Normally, 2-3 new bulbs are produced but the total aggregate weight produced is usually no more than double that of the planted bulb. For refrigerated bulbs, the yield is usually no more than the planted weight – i.e. no increase in weight at all.

The growth of the new bulbs is mostly in the period between flowering and senescence. To maximise this new bulb growth, the ideal conditions are cool-warm temperatures (say 15-20 degrees C combined with optimal nutrition and moisture. In warm climates, refrigerated bulbs often have a relatively short period between flowering and senescence due to a too-warm climate and effects of the refrigeration. Consequently, many of the bulbs produced will mostly not flower because they are too small. Tulip varieties have critical bulb circumferences before they will flower. For many varieties that circumference is about 8 cm but can vary from 6-9 cm for common varieties.

Therefore, problem number 1 for tulip growers in warm climates is that there may well be a shortage of bulbs that are of flowering size following growth.

2. The very long period of senescence

Dormant tulips are basically an energy store which also contains embryonic leaves, flower and bulbs for the coming crop. They are still alive and continually use energy and lose moisture. A commercial tulip grower will normally have the bulbs in storage from say, mid-December until mid-April – say 4 months, maybe 5. The December harvest will follow planting in mid-April and flowering in early October (the bulbs will not have been refrigerated).

A gardener in a warm climate will have refrigerated the bulbs and planted in, say, mid-May. The bulbs will flower in about late July-August and die back in late September. The following year they cannot be planted again because of the heat until mid-May. This is a period of about 8 months. This is a very long time to have tulips out of the ground and by this time the bulbs will be significantly compromised.

3. Summer heat

Tulips need a period of about 8 weeks following lifting to develop the flower for the new season. They do this best a temperatures of about 20 degrees. Once the new flowers are developed they are susceptible to abortion if they are subject to extended periods of temperature in excess of 30 degrees. For air conditioned homes this may not constitute a problem but in many situations it does, especially when high daytime temperatures are combined with warm nights as well.

How to Maximise the Chances of Second Crops

  

The above problems may make it look as if it is too hard and in some situation it probably is. Certainly, a third crop in warm climates will be extremely difficult. However, there are ways to maximise chances based on confronting the problems noted above.

  • Variety selection is very important if you want a second crop. On the other hand, if you wish to grow the tulips as annuals you can use virtually any variety.

Tulips vary in the amount of cold they need to produce good growth. For warm climates, it makes sense to use the varieties which need the least cold to flower successfully. These varieties are noted in our catalogue as being suitable for warm climates. Generally, they are members of the group of tulips known as “single lates”.

Varieties which need the least cold need the least time in the refrigerator and so will most likely produce the biggest crop of bulbs and also, possibly, die back the latest – thus minimising the time in storage.

Varieties such as Menton, Maja and Maureen may even grow without any refrigeration at all – although it would be advisable to give them at least a couple of weeks.

  • Storage of the bulbs is also important. Ideally the bulbs should be at about 20 degrees, well ventilated and free of aphids. Storage at temperatures around 25 degrees will be ok but a critical point is reached nearing 30 degrees where the new flowers will abort. The bulbs will then be put in the refrigerator for the desired time before planting when the soil has cooled to about 15 degrees.
  • Planting in optimal conditions also helps – provided viable bulbs with flowers inside them are used. In warm climates the bulbs are often planted in pots. Pots have the advantage that they can be moved and placed in total shade in the coolest place in the garden from planting until they emerge (say 5-10 cm high). Then they can be placed in whatever position is desired. This is good practice in cool climates as well.

Still too hard?

 

Comfort yourself with the fact that tulips have never been cheaper and in the last decade the real price has fallen by about 75%. Perhaps you can now afford this spectacular celebration of spring through annual purchase of the bulbs. Also, annual purchase allows tulip growing even in hot climates in Australia.

Refrigerating Bulbs

Refrigerating bulbs is a technique you can use to persuade your tulips to flower earlier, and to achieve maximum stem length, although it may result in a reduction in bulb yield next season.  To successfully chill your tulips only use large flowering sizes (10cm circumference and larger) and place them in an open paper bag in the vegetable drawer of the fridge for 6-8 weeks before planting.  What you are doing is stimulating the hormones in the bulb to convert the starch within the bulb scales to sugars.  This ready energy allows the plant to develop faster and flower earlier.  If you live in a warm climate area it will be essential to chill your bulbs, however in cooler areas such as Tasmania and mainland areas with cold, frosty winter nights, nature will complete this process for you.  Experiment and see what the response is in your environment.  Note: Do not refrigerate ANGELIQUE bulbs, as the bulbs from this variety will probably be too small to flower next year.

Storing Bulbs on Arrival

We recommend that you unpack your order on arrival, open the tops of the paper bags, and leave them in a well ventilated cool area. Keep away from ripening fruit or other sources of ethylene as this may produce flowering disorders, and try to ensure that the bulbs are not subject to sustained periods of high temperature.  Please check your order on arrival to ensure that it is correct.  If you find a discrepancy please contact us.

Tulip Families and Characteristics

Single Early Tulips – Usually early flowerers, that need to be chilled to get height for picking. Good upright leaves make them excellent for pots.

Triumphs – Medium height with upright leaves.  Can be planted closely (10cm).  Popular cut flowers but need to be chilled to give good length.  Great potted.

Darwin Hybrids – Multiply well, with broad leaves and medium height.  Need to be spaced wider if potted.  "Beautiful for massed plantings".

Rockery (Greigii & Fosteriana) – Very versatile and low growing, often featuring patterned foliage.  They can be left in the ground to naturalise.

Doubles – These varieties feature another whirl of petals and look fabulous wherever planted.

Fringed – Always stunning with their crystallised edges.

Parrots – These tulips are bred with feathered and irregular petals and provide an exotic and flamboyant touch.

Single Lates – These tall elegant tulips are well suited to Australia’s warmer climate.  The flowers retain their classic shape until the petals fall.

Dutch Iris

Dutch Iris are a most rewarding bulb to grow.  They prefer temperate climates, but will tolerate warmer conditions than tulips.  Soil conditions need to be similar, however planting can begin in early April.  Plant 8cm deep and 8cm apart and immediately water well to assist root growth.  Keep well watered throughout the growing season for best results.  The bulbs can be left in place year after year and are best planted in groups, which quickly multiply into free-flowering clumps.   Iris make excellent cut flowers and can be cut once the buds have begun to unfurl.

Narcissus (Daffodil and Jonquil)

Narcissus or daffodils can be enjoyed in all but sub-tropical and tropical climates, and they like a well drained, moist soil that remains as cool as possible.  In warmer areas, deep planting, mulching and leaf canopy cover in summer can be helpful in controlling excessive heat.  Generally plant 15cm deep (deeper in sandy soils) and 20cm apart.  The landscaping possibilities range from naturalising, to beds, borders and miniatures in rock gardens.  Like most bulbs they grow best in well drained soils with a pH of 6-7 and enjoy lots of water while they are growing.  Divide and spread bulbs out after 4-5 years.  Daffodils don’t need dry summer dormancy and enjoy some high potassium, low nitrogen fertilizer in winter when the leaves are emerging.  Please leave their leaves to die back naturally so that you get maximum bulb growth.

Crocus

Crocus enjoy well drained soil, deep planting (10-15cm) with a South facing aspect, plus a layer of mulch to keep them cool in summer.  They do need to be dry over summer as with many other bulbs.  They may be left undisturbed and are relatively disease free.  Crocus Chrysanthus feature multiple smaller flowers per bulbs.  The bulbs are also generally much smaller than the Crocus Vernus cultivars.

Anemones

These problem free corms love full sun, flowering late winter to early spring on 20-30cm stems.  Suitable to both warm and cool climates they enjoy well drained soil rich in organic matter.  Plant point down, 3-4cm deep and 12-15cm apart, and water well.  Top dress with blood and bone after flowering.  Bulbs can be left in the ground or lifted and stored should you wish to change their position.

Ranunculas

These small tubers can be grown throughout Australia.  They should be planted claws down, 50-75mm deep in well drained soil.  Plant them in a sunny position anytime from late Summer to early Winter.  They enjoy moderate applications of fertiliser.  When the foliage is yellowing off after flowering, they can be lifted and stored, however new stocks each year give the best display.

 

Freesias

Freesias enjoy a sunny position with well drained soil, enriched with a complete granular fertiliser.  Plant from March to May, 5cm deep and 7cm apart with the point of the bulbs upward.  The bulbs can be left undisturbed for several years with a top dress during the Autumn.

Hyacinths

Hyacinths can be grown in the garden, containers and even in a hyacinth glass.  They like well drained soil, enriched with organic matter, and can be planted in sun or partial shade.  Plant 10cm deep and 10cm apart in the early Autumn.  Mulch with compost and water them in.  They should not require water then until the shoot has emerged.  Check their moisture regularly then until the foliage dies back.  They can be top dressed with blood and bone after flowering.  They can be left in the ground from year to year in cooler areas, but in warm climates they benefit from pre-chilling, so harvesting the bulbs and storing in a well ventilated cool area is recommended.  Hyacinths rarely produce offsets.

Liliums

Liliums are winter dormant and grow throughout the spring, summer and autumn, usually flowering in January/February. Plant in full sun to shady location. More shade will result in taller stems but they may require staking.  Plant 15cm deep in well-drained, fertile soil with just a little blood and bone.  In the spring top-dress occasionally with complete fertiliser.  The bulbs do not need to be lifted.  They will die back in April/May and grow even better in the second year.

 

Zantedeschia

The Zantedeschia tubers (commonly known as Calla Lilies) grow best in dappled sunlight, or with some shade from the suns heat, and sheltered from strong winds. In very cold climates they are more suited to be grown in a conservatory. Building the soil up with some organic matter well before planting will help them to flourish. Plant Zantedeschias in late winter or early spring in well drained soil approx. 20-25cm apart and 5-8cm deep. Apply soluble fertiliser when buds appear and continue to feed while they are in bloom. They looked best when planted in clumps and are also wonderful pot plants. They will yield approx 4 flowers per tuber. They must be kept very well watered while they are in their active growing stage during spring and summer. But watering logging or poorly drained soils will cause plants to rot so watch carefully. It is important that Calla lilies never dry out, nor are water sodden. In cooler climates, calla lily tubers should be dug up and stored in a cool, dry place for the winter. This dormancy period is important in the development of a healthy vigorous tuber for subsequent planting.  The minimum storage time is 10 weeks, although they can be stored for as long 8-10 months without detriment. After the storage and dormancy period, the calla lily bulbs can be replanted. The picked calla lily flower has a long vase life, up to 2 weeks.

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