FAQs

Here is a collection of frequently asked questions that other gardeners have asked us as both beginning and more advanced flower bulb gardeners We hope that our solutions help you to experience the world of flower bulbs! Can’t find the answer to your specific question? Please do not hesitate to contact us.

Should I fertilise flower bulbs?

A customized fertilizing program keeps plants healthy and resistant to pathogens and pests and also cuts down on the use of chemical control agents. Proper fertilizing also ensures a good soil structure. There is a choice of fertilizing agents. Compost and manure are organic fertilizing agents. As described previously, they are also effective in improving the soil. Organic supplements provide a complementary balance to organic fertilizing agents. And then there are compound mineral fertilizers The type of fertilizing agent chosen depends on the kind of planting and the time at which the agent can be applied. For more information, please have a look in the landscape brochure. 

 

Is it true that bone meal is the best flower bulb food?

Once upon a time, bone meal was considered an excellent flower bulb fertilizer, but times have changed! Most bone meal today has been so thoroughly processed that the essential nutrients have been literally boiled out. Spring-flowering flower bulbs actually need no fertilizer for their first flowering season. A healthy Dutch flower bulb will already contain all the nutrients it needs to support one season of spectacular growth. Flower bulbs that will be left in the ground to naturalize will benefit from well-rotted cow manure or special flower bulb fertilizer when the shoots first appear in spring and again the following autumn. 

Why are flower bulbs often priced differently?

At the auctions in Holland, flower bulbs are graded according to their circumference which is then referred to as their bulb size. For each particular variety, the more mature flower bulbs are larger and will produce larger flowers. These bulbs demand a higher price. For high-profile bed plantings, it's worth the higher price paid for these more mature bulbs that will produce a showier display. But younger (smaller-sized) flower bulbs, which are often sold at lower prices, can offer a great way of adding color to large areas or marginal areas of the yard where they can be left in place to naturalize and mature, thus gaining in size over time. It should be noted that, for quality control reasons, the Dutch do not export flower bulbs smaller than certain established sizes. For instance, tulips must be 4 inches in circumference or the Dutch will not export them. This means that if you see tulip bulbs for sale that are smaller than this, they were not exported from Holland were no exceptions are allowed except for species tulips, which are naturally smaller in size to begin with. 

When do flower bulb growers in the Netherlands plant their flower bulbs?

Growers in the Netherlands plant their flower bulbs in November. They can do this because winters in the Netherlands never really start until mid-December. In regions where the winter starts earlier, it would be advisable to plant tulips in October. 

What is the Flower Bulbs Quality Mark Foundation Holland (SKBH)?

The Flower Bulbs Quality Mark Foundation Holland is a foundation that was established to offer consumers an independent sounding board for any complaints that might arise. You can thus contact this foundation if your flower bulbs have not provided the desired results. Sending a photo along with a complaint is not obligatory but can definitely support your position. You can also submit a complaint if the flower bulbs you purchased produced flowers other than those indicated on the packaging. Just make sure, however, that the SKBH logo appears on the packaging. 

Why are tulips grown in Holland of all places?

Tulips were introduced into the Netherlands at the end of the 16th century by Carolus Clusius. People in the Netherlands were quick to take an interest in these flower bulbs and started experimenting with growing them in the gardens around their homes. Because the demand for tulips grew, an increasingly professional approach was devoted to their cultivation, and it turned out that the coastal area – and especially the strip of land just inside the Dutch dunes - had the perfect conditions for this. The marine climate with its mild winters and cool summers, proper drainage with a consistent water level, the right type of soil and the fact that the Netherlands was a center of trade were all very beneficial factors. With the increasing urbanization occurring in the traditional flower bulb growing regions, the most important growing areas today are located in the northern regions of the Netherlands where there is still enough land available for flower bulb growing. This will assure their cultivation in the Netherlands for a long time to come. 

Are there flower bulbs that scare off mice and/or rats?

Unfortunately, no flower bulbs have the capacity to really scare off mice or rats. There are a few precautionary measures that can be taken to keep these pests from eating your flower bulbs, however. First, plant the flower bulbs deeply enough and cover them properly with soil so that mice and/or rats are not attracted to the planting site. Secondly, cover the border where the flower bulbs have been planted with some finely meshed wire netting. Lay out this netting so that it more than covers the border and then push the edges of the netting slightly into the soil. 

Can I use a Spring Meadow flower bulb mix in my own garden?

This formula – the “Spring Meadow” – has actually been realized at Keukenhof gardens in Lisse. Keukenhof is the largest flower bulb display in the world. In April and May, 7.million flower bulbs cover this large site to the delight of thousands of visitors every year. At a number of sunny places in the lawn, wave-shaped areas were cut out of the sod to a depth of more than 4 inches. These shapes were filled with sharp sand that was then mixed together with the soil below and above it. This created perfect spots to plant small flower bulbs for naturalizing: over a surface of around 600 square yards, 55,000 flower bulbs composed of 35 different kinds were mixed and scattered and then planted by hand. At Keukenhof, the planting of these flower bulbs was also accompanied by the sowing of a flower meadow seed mix so that the flower bulbs would emerge among a haze of herbaceous plants that would then provide weeks of color once the flower bulb flowers had faded. Any bulbous plants suitable for naturalizing that also have a more or less “uncultivated” look can be included in this kind of mixture. The flower bulbs used for the Spring Meadow at Keukenhof were distributed at a rate of approximately 180 bulbs/square yard and were made up of the following varieties:

  • Bellevalia pycnantha
  • Chionodoxa forbesii
  • Chionodoxa luciliae
  • Crocus tommasinianus 'Ruby Giant'
  • Crocus tommasinianus 'Whitewell Purple'
  • Leucojum aestivum 'Graveteye Giant'
  • Muscari aucheri 'Blue Magic'
  • Muscari 'Valerie Finnis'
  • Narcissus 'Jack Snipe'
  • Narcissus 'Jetfire'
  • Narcissus poeticus recurvus
  • Narcissus 'Topol’
  • Ornithogalum umbellatum
  • Scilla siberica
  • Tulipa bakeri 'Lilac Wonder'
  • Tulipa clusiana
  • Tulipa clusiana 'Lady Jane'
  • Tulipa linifolia
  • Tulipa tarda
  • Tulipa urumiensis

Can I plant flower bulbs among trees and shrubs?

Flower bulbs planted in these locations have to be strong enough to “go it on their own”; in other words, to be able to take care of themselves between such powerful competitors. In addition, the kinds that flower earliest are often the kinds chosen for these sites since they are easily visible among the woody plants that are still bare. Perfect here would be a mixture of at least six varieties of naturalizing flower bulbs that have successive flowering periods. Such a combination planted in variously sized clusters in the lightest spots of a wooded area or along the edge of a wood will ensure years of flowering that becomes increasingly profuse year after year. 

Should tulips be deadheaded once the flowers start to fade?

Tulips planted for multiple-year flowering should be deadheaded once the flowers start to fade. This prevents the development of seedpods, a process that uses the plant’s energy resources to produce seeds instead of new bulbs. Deadheading is the name given to breaking the flowers off from the stem. This also prevents petals from falling into the leaf axils and allowing Botrytis to develop. 

When is the best time to mow the lawn with crocuses and daffodils in it ?

As a rule, mowing grass strips containing flower bulbs is not started until an average of 6 to 8 weeks after flowering. Grassy areas planted with flower bulbs can be mowed only after all the aerial parts of the flower bulbs have withered back. Some flower bulbs such as Chionodoxa, Scilla and Eranthis propagate by seed, so their seeds should get a chance to mature. 

Do tulips prefer a sunny or a shady spot in the yard?

Tulips are sun as well as shade lovers. But when planting your tulips this fall, don't be fooled by the patterns of sun and shade in the fall garden! Remember that come spring, when tulips bloom, all the deciduous, non-evergreen trees in your yard will be beautifully leafless. There's a lot of sun in a spring garden! 

Is it better to plant flower bulbs earlier or later in the fall?

Planting times vary, depending upon your climate zone, but as a general rule, earlier is better. Flower bulbs need to establish strong root systems, before the frosts of winter set in and the flower bulbs enter a new cycle in preparation for spring blooming. Remember to plant flower bulbs in an area that drains well and water newly planted flower bulbs to help those roots get going! 

What are 'botanical' or 'species' tulips?

“Species tulips” is the name given to varieties which have not been bred or hybridized and remain essentially the same as the ones found growing in their natural habitats. Botanical tulips are hybrids but hybrids which remain very close to the original species. Neither of these terms refers to "wild" tulips. All tulips sold by the Dutch, including the species and botanical tulips, are actually propagated and grown in Holland. Species and botanical tulips are generally smaller than other tulips. They are especially prized for growing in rock gardens. 

I've been told that the bigger the tulip bulb, the better the flower. Is this true?

Not entirely. It is true, however, that, as a general rule, the bigger the tulip bulb the bigger the flower. But bigger does not necessarily mean better. The flower bulbs of a species tulip such as Tulipa tarda, for example, would appear quite tiny beside, say, a large Darwin hybrid flower bulb such as ‘Apeldoorn’, but these small species tulips are some of the most delicate and lovely bulb flowers you can grow. They're quite hardy as well. Tulip bulbs are sold by their bulb size measured in centimeters around the circumference. Within any particular type or variety of tulip, the larger bulbs will demand a higher price than the smaller ones. For big showy displays, bulbs with the larger bulb sizes are certainly worth the price. However, you can get some excellent bargains by buying lots of smaller bulbs for brightening up a marginal spot in the spring yard. 

Which tulips are the most famous?

The most popular tulips of all are the red ones such as ‘Apeldoorn’ and ‘Oxford’. These cultivars have been the front-runners for years and years – every shop always has red tulips for sale. But the most famous tulip by far has to be the “black” tulip: ‘Queen of Night’. Although this cultivar is not a true black – the color is actually a very deep purple – it’s very close resemblance to black creates a magical effect. After centuries of breeding efforts to develop a truly black tulip, this is still as close as we’ve been able to get. 

The Fritillaria imperialis bulbs I bought have a really bad smell. Is there something wrong with them?

No, this is a natural characteristic of the flower bulbs and flowers of Fritillaria imperialis. (A Dutch nickname for the Crown Imperial is “stink lily”.). But a useful side effect is that the scent of Fritillaria imperialis bulbs keeps moles out of your garden. 

Which flower bulbs can I plant outside?

Since spring-flowering flower bulbs can easily withstand even a fairly harsh winter, almost all of them can be planted outside. They even need a cold period in order to flower. The exceptions are Hippeastrum (Amaryllis) varieties and Narcissus ‘Paperwhite’. These should not be planted outside, but should be planted in pots and kept in a cool spot until December or January. At that time, they should be placed in a warm room where they will produce flowers.

Can you plant flower bulbs in any kind of garden and in every type of soil?

Flower bulbs can be planted in any garden and/or every type of soil. The most important thing is that the part of the garden where the flower bulbs are to be planted must not become too wet during the winter. Water that remains in puddles several days after a rain will absolutely ruin a bulb border. About the only other exception involves the Checkered fritillary (Fritillaria meleagris) that will not grow well when planted in dry soil such as that found under a Thuja. And, although heavy river clay makes it difficult to dig planting holes for tulips and daffodils, they will thrive in this type of soil. 

Can I plant flower bulbs among the roots of perennials and shrubs?

Flower bulbs will thrive among the roots of perennials and shrubs. Bulbous plants emerge early, at a time when perennials and shrubs are not yet in leaf. This means that the flower bulbs will have plenty of light and space to create a lovely flowering display. Even so, it is sometimes more difficult to get the flower bulbs into the soil. The soil is often hard, and the roots can make digging the holes for the bulbs difficult. For these reasons, make the planting holes as small as you can and plant each flower bulb separately in its own little hole. To make things easier, you could try using a special flower bulb planter; this tool will also minimize damage to the roots of the perennials and shrubs. 

Which bulbs have the strongest smell?

Fritillaria imperialis and the various Allium species are the flower bulbs with the strongest smell. Chives (A. schoenoprasum), ramson (A. ursinum), onion sets (A. cepa), shallots (A. ascalanicum) and garlic (A. sativum) all belong to the Allium family. The scent of other members of this family is similar as well. The strong smell of Fritillaria imperialis keeps moles out of your garden.

How can I keep mice and rats out of the garden?

Mice and rats are found everywhere, so it’s difficult to prevent them from entering your garden. The best way to discourage them, however, is to keep the garden tidy at all times – no piles of leaves left lying around and never any remnants of food or other refuse left about. Mice in particular can be discouraged by keeping seeds out of your garden. To do this, snip off all flowers as they fade and make sure that your bird feeder is high off the ground where it will be inaccessible for mice. This latter piece of advice, however, is difficult to follow since mice are such acrobatic little creatures. 

What should I do after tulips fade in spring? And what about daffodils?

After tulip flowers have faded, "dead-head" them by clipping off the faded blooms so that they won't go to seed. Narcissi (daffodils) do not require dead-heading, so you can, just leave them as they are. The main thing that flower bulbs need during their post-flowering period is for their foliage to be allowed to die back naturally so the plant can put its energy into "recharging" its flower bulb for next spring's performance. 

Do flower bulbs have to be lifted after they flower?

Flower bulbs that you have bought for naturalizing can simply be left undisturbed. These flower bulbs will come back year after year and even increase in number. As for other flower bulbs, never remove them from the soil right after they flower but wait at least until their foliage has died back entirely. In this way, you give the flower bulbs a chance to grow and store the energy they will need for next year. Not only is the lifting and storing of flower bulbs a difficult chore but it frequently leads to disappointing results as well.

How should I allow flower bulbs to naturalize?

You should let flower bulbs naturalize by not lifting them from the soil. After they bloom, the plants have to be given the chance to die back naturally so that they can store newly produced nutrients in their flower bulbs for flowering again next year. Many flower bulbs, however, are not suitable for naturalizing purposes. This is why you should be sure to check the information on the packaging when you buy the flower bulbs to see they are suitable for naturalizing. Naturally, you can always experiment with other kinds to see if they might be suitable for naturalizing in your particular garden.

What are naturalizing flower bulbs?

Naturalizing flower bulbs are flower bulbs, corms and tubers that will come back and flower year after year. If information on the packaging indicates that the flower bulbs are suitable for naturalizing, they do not need to be lifted from the soil. Naturalizing flower bulbs will flower again next year and can even increase in number.

What should be done before storing the flower bulbs?

Storing flower bulbs
Not all flower bulbs can be left undisturbed in the soil. Tulips, for example, are susceptible to diseases, and gladioli cannot tolerate frost. If you still want to enjoy flowers produced from the same bulbs next year, you will have to store these flower bulbs.

What should be done before storing the flower bulbs?
If you want to store your flower bulbs, it is important to trim off any wilted flowers as soon as they are finished flowering. By trimming off the flowers, you keep the plant from using its energy to produce seedpods; instead, this energy goes into making the bulb itself stronger. By also proving some extra fertiliser, you will get extra strong bulbs.

Lifting flower bulbs
The flower bulbs can be taken out of the ground once the leaves and stem have completely died back. This is also referred to as lifting the flower bulbs. After lifting, it is advisable to brush off most of the soil clinging to them. Flower bulbs have to be kept dry during storage or they will quickly rot. For this reason, do not wash the flower bulbs before storing them.

Bulblets
Flower bulbs propagate by producing small bulbs from underneath. These are known as bulblets. When the flower bulbs are lifted, these bulblets can easily be removed along with the original bulb’s old tunic and roots. This is referred to as pealing the flower bulbs. Like the mature bulbs, bulblets can also be stored and planted out for next year’s growing season. A few years later, they will produce beautiful flowers.

What is the best container for storing flower bulbs?
The best container for storing lifted bulbs and bulblets is a cardboard box. Place the bulbs layer by layer in the box with a sheet of newspaper between each layer. When all the flower bulbs are in the boxes, store them in a cool dry place such as a cellar or wardrobe. As you can see, storing flower bulbs is not that difficult.

Information organic flower bulbs

Organic flower bulbs
You can recognise organic flower bulbs by the certification label indicating organically grown products. These flower bulbs have been organically produced. This means that they have been grown without the application of nonorganic fertilisers, chemical crop protection agents and pesticides. The organic agriculture standards applied to the production of organic flower bulbs are based on preserving the environment, biodiversity and landscape and apply throughout the EU.

Monitoring the organic production of flower bulbs
Skal Biocontrole monitors whether flower bulbs are being produced in compliance with the organic agriculture standards that apply to flower bulbs. This organisation serves as an agency that monitors the reliability of organically grown products, including organic flower bulbs, in the Netherlands. ‘Organic’ is a legally protected term. Legislation for organic production is aimed at preserving and justifying the trust of consumers in organic products. An organic flower bulb may bear this qualification only if its production process complies with statutory regulations. European authorities determine these regulations, the certified organic bulb producers comply with these regulations, and the Ministry of European Affairs commissions Skal Biocontrole to monitor this compliance. You can thus be sure that organic flower bulbs really are organic.

The supply chain
The entire supply chain that handles organic flower bulbs has to be certified. This means that all the organisations that produce, process, package, import, market and store these flower bulbs have to comply with the requirements that apply to organic flower bulbs. The production of organic flower bulbs involves more risk than the production of conventionally produced flower bulbs. The reduced use of fertilisers and the limited options for controlling diseases and pests during cultivation mean lower yields of organic flower bulbs than conventional flower bulbs. This is why the costs for producing organic flower bulbs are higher than for conventional flower bulbs.

The advantages provided by organic flower bulbs
The price for organic flower bulbs is higher than for conventional flower bulbs. On the other hand, buying them provides extra advantages:

-          Cultivating them involves no use of chemical crop protection agents and nonorganic fertilisers.

-          Cultivating them involves no release of undesirable substances into the environment (into ground water, drainage ditches, etc.)

-          Efficient use is made of scarce raw materials such as minerals and fuel for energy.

-          Fewer flower bulbs are planted per square metre so that the plants are grown in a healthier, more natural way.

-          More attention is devoted to the crop in the form of regular and accurate plant monitoring.