Indoor Flowering Plants – Growing Indoor Flower Bulbs

indoor flower bulbs

Growing Indoor Flower Bulbs

Growing flower bulbs indoors and for the home is rewarding in many ways. I find it an especial pleasure to have at such close proximity, plants which I have nursed along carefully for several months, to provide colour during the late winter. You must too, I feel, approve instinctively of a gardening activity in which virtually anybody, with or without a garden, young or old, well or in poor health, can engage on more or less equal terms. I say ‘more or less’ because those of us who own gardens have an obvious advantage in having space to start growing flower bulbs outdoors, before bringing them into the home. But countless householders manage to find a suitable cool, dark place where the bulbs can be kept for the first eight weeks or so, for example under the stairs, in an empty cupboard or an attic.

I shall now outline the various stages that flower bulbs must go through when they are grown for the home, the treatment they should be given to get the desired results, and the types of containers and mediums which can be used and how effective these are in practical terms.

Growing Flower Bulbs in Containers and Growing Mediums

So far as containers are concerned one can say, in the modern idiom, almost anything goes – provided, of course, that the container in question is large enough to hold a reasonable number of the chosen bulbous plants, and its depth also is sufficient to allow good development of the roots.

Containers without drainage holes have the advantage that they can be placed on tables and elsewhere without anything underneath them to collect excess moisture. This is a considerable convenience but it means that bulb-fibre – a mixture of peat, coconut fibre, charcoal and oyster shell (the last two to keep the mixture sweet) – must be used, and it is generally agreed among gardeners that for absolute top results it is better to use a good soil mixture. However, provided a good bulb-fibre mixture is purchased, this is something which should not be over-emphasised. Given good cultivation – and especially watering – bulb-fibre will give excellent results.

If a container with drainage holes is chosen, make sure that the soil compost used is suitable for this type of plant. It should have plenty of body in it but at the same time drainage must be good. The John Innes No. 2 Potting Compost is an excellent mixture but if one prefers to make up a mixture then 3 parts high quality loam, 1 part peat and 1 part sharp sand gives very good results.

Gravel is used as a rooting medium for hyacinths and the earliest daffodils as well, but as it has nothing to give the plants during their development one would not expect to get such strong-growing plants in this way. The gravel must be kept moist but too much water must not be allowed to collect in the bottom of the bowl. Vermiculite can also be used as a rooting medium but I am not altogether happy about this as it does not support the bulbs, and flowering-size plants, even when staked, tend to topple over.

Another method of cultivation which is rather fun for children is the hyacinth glass, used again for hyacinths and the earliest daffodils. Here it is possible to watch the bulbs send down their roots into the water and develop gradually until they are fully fledged flowering plants. Also available are plastic bowls with indentations in the top cover to hold the bulbs. The roots have access to the water in the container.

Before discussing these growing methods in more detail there is one point about containers which should be mentioned now. Some, like conventional clay flower pots, are made of absorbent materials. These must be immersed before first use in water and left until air bubbles cease to rise. If this is not done moisture losses through the sides will be excessive, to the detriment of the plants.

Indoor Flower Bulbs Grown in Fibre

Make absolutely sure before using bulb fibre that it has been thoroughly soaked in water. Dry bulb fibre used for potting-and it is always sold in this state-cannot absorb anything like the amount of water needed to satisfy the moisture requirements of the bulbs.

There are several ways of soaking fibre and if only a small quantity is involved the best way is to half fill a large bowl with fibre and fill it to the brim with water. Allow this to soak overnight and then squeeze out excess moisture with the hands before using for potting the bulbs. If the amount of fibre to soak is large, spread it out on the ground and then soak thoroughly with a hose pipe or with a watering can. Allow this to drain overnight. A third method is to immerse a sack of the fibre in a water tank. This, will mean taking the sack out several times usually, and moving the fibre around, for otherwise the fibre at the centre of the sack stays dry and the results are not entirely satisfactory. This saturated fibre should also be allowed to drain before being used. A simple test of the suitability of fibre for potting is to compress a handful and release it. If it falls away readily it can be considered in fit condition to use.

The potting procedure is simple but should nevertheless be carefully carried out. Place a few lumps of charcoal in the bottom of the container to keep the fibre sweet. Cover this with a layer of fibre and press this gently into place. (The reason why this must be done gently is that a hard layer of fibre under the bulbs would act as a barrier to the roots. Consequently, these would then exert pressure upwards and soon displace the bulbs.) Place the bulbs on the fibre, again gently, and fill in around them with fibre, firmed securely into place with the fingertips. Give the fibre a good soaking and after an hour or so turn the container on its side to drain. The bulbs are now ready for the first phase of their growth cycle and are plunged outdoors or stored in a cool, dark place indoors.

Indoor Flower Bulbs Grown in Compost

I want to emphasise the importance of good drainage when indoor flower bulbs are grown in containers. As in normal potting, cover the drainage holes with large crocks and these in turn with a thin layer of smaller crocks before adding a layer of fibrous material and the compost in which the bulbs will grow. Seat the bulbs at the correct depth in the compost and firm the compost around them with the fingertips.

Plunging Bulbs

With the bulbs in their containers the next move is to plunge them outdoors under ashes of about 4 in. thickness or in a cold frame or garden shed. If such facilities are not available the alternative is to store them in a cool – repeat cool – dark place indoors. The objective now is to get the plants to make a good root system before any top growth is made. Low temperatures and darkness ensure that this objective is achieved.

The Next Stage

After four or five weeks of this treatment, periodic inspections should be made to see whether growth has been made. The top growth will, of course, be blanched due to the lack of light and when they are ready to take out of the plunge bed – when the growth is about an inch high for daffodils and hyacinths and rather more for tulips – they should have about a week in half light before being subjected to normal conditions.

The water requirements of the plants must now be watched very carefully for they must never be allowed to dry out. For the time being keep the bulbs in cool conditions and only take them into the house when growth is considerably more advanced. For example, daffodils and crocuses should only be brought indoors when the buds have formed. When the time comes, the introduction to heat must be gradual, only providing the plants with living room temperatures when they are about to flower. Too much heat too soon results in etiolated growths, general weakness and, inevitably, poor quality blooms.


Taller bulbous plants like hyacinths, daffodils and tulips should be staked early before the growths have a chance to sag. The staking should naturally be done as unobtrusively as possible so that the appearance of the plants is not spoilt, using light twiggy branches or thin canes as circumstances dictate.

29. September 2010 by Dave Pinkney
Categories: Bulbous Plants, Plants & Trees | Tags: , , | Comments Off on Indoor Flowering Plants – Growing Indoor Flower Bulbs


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