It may perhaps not have been the greatest year for the British gardener, what with the hosepipe ban followed immediately by some of the wettest Spring and Summer months on record. And now as the year begins its draw to a close we have the spectre of Ash dieback disease (Chalara fraxinea) looming over us! The beauty of horticulture and gardening however is that Spring and the optimistic hope of a better year is always just around the corner. As I sit here today the Autumnal rains are thrashing down and the papers are talking of another harsh Winter ahead but here at Chartwell we are already planning for Spring, even though it may seem like a little way away yet!
One of the fun jobs that we do every Autumn at Chartwell is to force daffodil bulbs (Narcissus cvs.) over Winter so that we can use the blooms as early as possible for cut flowers in the house. This is a process that became popular in this country in the early 1800’s. It has been carried out in Churchill’s garden for many years and is one of the tasks which we still continue to this day. This practice is also carried out by commercial growers the world over and is something that most home growers can have a go at too.
The idea of bulb forcing is a process used to make certain bulbs flower earlier than they naturally would by altering their biological clock. Many bulbs are usually dormant during Winter before flowering the following Spring or Summer. The forcing process prompts the bulb to put on early growth and therefore early blooms. Hyacinths are commonly forced for indoor Christmas flowering for example. The house here at Chartwell is closed over Winter however so we force daffodils instead for early Spring flowering.
There are many ways of forcing bulbs but they all essentially work in the same way. At Chartwell we choose daffodil bulb varieties suitable for forcing such as N. ‘Salmome’, ‘Thalia’, ‘Cragford’, ‘St Keverne’, ‘Pheasant Eye’ and most aptly of all, Narcissus ‘Sir Winston Churchill’. These bulbs are often heat-treated to speed up the forcing process, although this makes them slightly more expensive to buy. The next step is to place them on the surface of compost filled wooden crates as shown above. They should be placed close together but not actually touching as this can induce rotting. This stage can be done any time during October or November, depending on how early you want the blooms.
The planting material is a mix of our own ‘home made’ compost together with some peat-free purchased compost and some perlite or potting grit for extra drainage. It is important that the bulbs remain moist but do not get too wet and therefore rot. These deep crates are then topped lightly with more of the same mix. At this point the crates are back-breakingly heavy so taking them to the forcing pits is most certainly a two-man job!
Each crate is labelled and then placed at the base of the bulb forcing pit that is dug each year out of an area of very gritty soil next to one of our glass houses. The wall against which they are placed is west-facing meaning that although it will get some sun, the temperatures here will be cold enough to trigger the bulbs to produce plenty of growth shoots. Narcissus bulbs generally tend to take between 15 and 17 weeks at this sort of temperature to put on the required growth.
The crates in the pit are covered with at least 6 inches of the soil and then are left to do their thing over Winter. Canes have been placed at the corner of each box so that the act of digging them up is that much easier.
After the allotted cooling time has passed we will dig up the forcing crates and bring them into our potting shed for two to three weeks of warmer conditions. This will stimulate the pale green shoots produced in the pit to actually produce their flowers. I will endeavour to cover this part of the forcing process in a future blog post.
This all may sound like a lot of work to some of you but it really isn’t. Although forced bulbs often flower for shorter periods than normal, we find that they fill an important gap in the flowering season when there will be little else to take up to house and decorate the rooms with. And it is certainly a better and more sustainable idea than buying in imported bulbs or flowers for the same effect. Come and pay us a visit next Spring to see the house displays for yourself…