Most bulbs can be grown indoors – for a short period of time! Cyclamen are the main exception, in that they can be successfully grown in the house for the whole of their life. Not easy, but possible.
Other bulbs are generally bought into the house for flowering period – often at Christmas – but spend most of their growth cycle out of doors or in a cool garage. Whilst bulbs for Christmas are an obvious target - for presents and holiday feel, bulb can be more easily bought into flower a little later.
Most of us will have seen the hapless schoolchildren, trying to get their prize daffodil to school for the annual daffodil growing competition. Often having to be help up with a 2 foot long cane – or simply waving around in the breeze! There is a simple reason for this – explained below.
The first thing to realise is the fact that bulbs are not ‘natural’ indoor plants, and that the type of bulbs we normally try to grow or flower indoors, are normally those that prefer to have the main part of their growing/preparation time, with their bulb and roots in cold soil. Far colder than is the norm in the house!
There are others – such as Cyclamen – that are generally sold as potted flowering plants – during the winter – Christmas in particular. These can simply be taken indoors and treated like normal houseplants.
Narcissus, Hyacinths, Crocus and Tulips, basically require the same growing requirements for successful flowering indoors. The exception to these are the specially prepared Hyacinths - of which more on another page about growing Hyacinths Indoors - and Hippeastrums, which can spend their entire growing period indoors.
Planting the Bulbs
The bulbs should be put in their growing pots in late August or early September - using bulb fibre, and not potting compost - although a soil based compost may be used as an alternative - if there are drainage holes to the pot. It is normal not to have drainage holes - with either plastic or earthenware bowls being used. In this case, bulb fibre is a must!
A decent sized bowl - some 8in across or more - will hold between 5 and eight bulbs. Crocus would be better in bowls with a smaller diameter.
Half fill the bowl with bulb fibre, and sit the bulbs on top of the bulb fibre. It is best to use just one variety of chosen bulb and not used mixed varieties - unless you want them flowering at different periods. Sounds a good way to do it, but rarely works in practice!
The bulbs be positioned quite close together, but best to to be touching each other. Once positioned, then more bulb fibre is added, just leaving about the top third of the bulb exposed. The bulb fibre level should finish about an inch below the rim of the pot. This will allow you to water the pots indoors with less risk of splashing onto furniture etc. Leaving the top of the bulb exposed has two other purposes. a/ to prevent rotting of the neck, and b/ to make the finished flowering bulb display more attractive - especially if live sphagnum moss is gently laid around the bulb cluster when bringing indoors. Coloured pebbles can also be used for this.
Growing the Potted Bulbs
Now for the part which often causes dismal failure in the finished product.
After potting, the bulbs must be kept in a dark COOl or COLD place. As long as it is frost free, it is fine. The garage or garden shed is ideal. Keep the potted bulbs in the dark by covering with a black polythene sheet, or simply placing the potted bulbs in a black plastic bin liner. REMEMBER NO heat; NO Light. So the airing cupboard is a no go area - as is the cubby-hole under the stairs. (If you venture out into your garden around Christmas time, you will see many types of bulbs poking through the soil in spite of the cold or freezing conditions. They need that cold spell to alert themselves to the fact that spring is about to happen - and they know that that they need to get ready for the spring flowering event.
What you are doing by treating the bulbs to a long cold and dark spell in the garage or shed, is tricking them into believing they are in the middle of winter! Sorry bulbs, but we have to do it!
Keep an eye on the bulbs - in particular for them to start sending up their leaves. Now you can start to bring them into flower. Slowly and not in too much heat, otherwise they will grow too quickly - resulting in tall flower stems that will require tying to supports! With experimentation, you can move the pots into a slightly more warm room, removing the black sheet, and ferrying the post between cold and warm conditions to get the timing right for any special event. Otherwise just gradually increase the temperature until the bulbs are perfect. Don't be afraid to arrest any quick growth by a short spell back in the cooler - but without the black cover this time.
The commercial growers for potted bulbs that you see in the garden centres in early spring, normally leave their potted bulbs out in the winter, in huge bed. The potted bulbs are then covered with a 4inch layer of sand or peat - to keep them in the dark. Then they are lifted from these preparing beds just as the shoots start to show through. That is why you often see this type of potted bulb, with yellow stems at the bottom. Light deprivation prevents the greening process. No problem - soon to turn green in normal light.
Look forward to seeing photographs of you successes - or failures!