HOW TO GROW MINIATURE DAFFODILS
There are probably as many different growing regimes as there are growers. This is an outline of the methods that I use in North Yorkshire, modified over 30 years with experience and tips from other growers, notably Ian Young in Aberdeen. If you are a bulb enthusiast, you really must have a look at Ian's Bulb Log on the Scottish Rock Garden Club website, where there is a wealth of superb photography and in-depth information on growing bulbs of all kinds.
My daffodil growing year begins in June with all the bulbs dormant in their clay pots in a dry sand plunge, the remains of their foliage lying straw-like on the surface of the pots. If possible, I like to repot all my mature bulbs into fresh compost every year. This makes it possible to check on the health of the bulbs, and to harvest surplus stock for sale or exchange. It also minimises the need for supplementary feeding during the growing period. Repotting is always looked forward to, and accompanied by a feeling of excited anticipation like the day before Christmas, each pot like an unopened present waiting to surprise you with its hidden contents. Will there be more, fewer, or indeed any bulbs in there?
Repotting begins with knocking out each pot and sieving out the bulbs from the dry compost. It is a good idea to wear a dust mask while doing this as the perlite dust can cause respiratory problems. The bulbs are cleaned of loose scales and checked to see if they are sound and healthy. Soft or damaged bulbs are discarded. For the last few years, I have dipped all my bulbs before potting them in a solution of formalin for 30 minutes. To facilitate this, I put each cohort of bulbs into an organza drawstring bag sold for such things as wedding 'favours' and jewelry, enclosing the label in the bag. They are then hung out to dry in a windy place, preferably not in full sun if dealing with small bulbs without brown tunics, to avoid dehydration.
I like to grow all my mature narcissi in clay pots plunged in 25cm deep sand under glass. The plunge medium is ordinary ‘sharp’ builder’s sand, sometimes called ‘grit sand’, and can be bought quite cheaply in bulk from builders’ merchants. Other growers manage their plants equally successfully in plastic pots, but clays are my personal preference as they cut down on watering, since if the sand is kept moist during the growing season, the plants can absorb water through the sides of the pot as needed. The sand will also draw out any excess moisture, and so avoid waterlogging. Another benefit is to buffer temperature so they do not freeze during the winter. Clay pots are not difficult to clean if they are first soaked in a dustbin full of water, with some bleach added, for 24 hours before being washed. This softens any deposits of lime or algae so that they are easy to remove with a washing-up sponge. They are then rinsed and allowed to air dry.
The next job is to mix up the compost. This is usually a mixture of two parts John Innes No2, two parts perlite. A slow-release general fertiliser can be applied at the recommended rate before the pile is thoroughly mixed - I usually use Vitax Q4. In practice, the same basic compost is used for almost all my bulbs.
I begin the repotting with the bulbs that come into growth soonest. These are generally hoop-petticoat types such as Narcissus romieuxii and cantabricus, which may begin producing roots in late July even if bone dry. The contents of the pot are removed until the layer of bulbs is revealed. The mass of bulbs is then tipped into a small sieve and shaken gently to remove the compost. Each bulb is checked to see that it is firm and any loose tunic is removed.
Recently, I have begun to dip my bulbs before shipping or replanting; for this I use a Formalin solution at the recommended rate, and thoroughly dry the bulbs immediately after dipping. I think this has dramatically reduced fungal diseases on the bulbs.
A clean pot is chosen, ideally of a size to take the bulbs fitted closely together (almost touching each other) in one or more layers. The pot is prepared by covering the drainage hole with a small piece of plastic netting such as that used for shading, and one third filled with prepared compost. I do not advise the use of ‘crocks’ over the drainage hole, as the compost needs to be in contact with the plunge medium through the holes in the netting in order to establish the capillary action that will stabilise the moisture content of the compost, especially if using a plastic pot. The compost itself, if properly made, will act as the drainage medium.
A 1cm deep layer of clean, coarse, washed horticultural sand is then added and the larger bulbs are placed close together on this. If there are a lot of bulbs, the first layer is covered with more sand and then a second layer placed on top so that they lie between the bulbs beneath. The very smallest bulbs can be placed in yet another layer on top of this. Sometimes there can be, for instance, over 100 bulbs in a 17cm(7”) pot. Obviously if there are only a few bulbs there will only be a single layer, but the smallest size of pot that they will fit into is used, as they seem to grow best when in close proximity to their neighbours. If I only have one or two bulbs of a taxon, then they will share a pot with 'pot buddies/potpals' so that they get some company for their roots. The different potpals are separated within the pot by sections of cut-up plastic bottles. It just needs a little extra care when repotting to empty out each section without mixing the different taxa.
If the harvested bulbs are elongated rather than rounded, this can mean that they would be better in a deeper pot. Elongated bulbs will rarely flower, so planting deeper will often induce flowering in difficult-to-flower varieties such as ‘Stocken’. For each pot the label should be replaced if necessary, and updated to show the number of bulbs in the pot for that year.
The final layer of bulbs is just covered with more sand (at which point I usually settle the sand around the bulbs using a trickle of fungicide solution) and then the pot is filled with compost to within 1.5cm of the rim and finished off with a 1cm layer of coarse (6mm) grit.
Ideally the pot should be re-plunged immediately, as this will buffer the temperature and prevent the contents of the pot from overheating in hot weather. As each plunge bed is filled, the plunge sand only is watered to settle it around the pots and ensure close contact between the pot and plunge medium. The rest of the bulbs are repotted in rough order of flowering, usually N. jonquilla and N. watieri being left until the end.
After the mature bulbs are completed, attention turns to the young bulbs. One-year-old seedlings are left in the same pots for another year, but the old foliage is removed and a sprinkling of slow-release fertiliser is applied to the surface of the pot. Two-year-old seedling bulbs are potted up into clay pots from their plastic seedling pots, even very small bulbs being placed halfway down the pot in their layer of sand. Seedlings can take from 1-5 years to flower, but will usually flower in their third year.
By this time it is usually the end of August. Hopefully all the bulbs have been repotted or top-dressed, and re-seated into the plunge. Around 1 September (if possible - I am often still repotting!) all the pots are given a double watering (the first “monsoon”) to ensure that the compost is thoroughly wetted. The plunges are also watered at this stage. A month later on 1 October a second monsoon is given in the same way. By this time some of the earliest bulbs will have foliage visible.
The next few months are spent watching the cycle of flowering and keeping an eye open for any signs of disease or pests on the plants. The watering consists of keeping the plunges moist and giving a little extra water to those pots showing a lot of growth. In very cold weather, watering is held back to keep the compost on the dry side, which will help to prevent frost damage to the bulbs.
All my glasshouses have a small electric fan heater, which helps to stop temperatures falling very low, although in the winter of 2010-11 temperatures for some days fell as low as -7ºC despite the heaters. Luckily, the fact that the pots were plunged seemed to help prevent too many losses.
As each species begins to flower decisions are made about which plants to breed from. Narcissus species can be propagated simply by allowing insects to pollinate the plants, but I usually prefer to hand pollinate just in case. Rather than using a brush to transfer the pollen, I use forceps to pick off a stamen with a mature anther shedding pollen, and brush this against the stigma of the other flower. If there is only one flower on that species, the flower is self-pollinated to obtain seeds.
If different species/varieties are to be crossed to produce hybrids, then the female parent is selected as soon as the flower begins to open, and the undehisced stamens are removed to prevent self-pollination. Pollen is transferred from the male parent as above, and then the perianth and corona are removed to make the flower unappealing to insects and minimise the risk of unwanted pollen reaching the stigma. It is essential to label the flower with the parentage of the cross; for this I use small strung tags used for pricing items in shops, and an indelible pen.
Not all attempted crosses are successful. Some fail because of sterility of one of the parents, for instance N. ‘Cedric Morris’ is incapable of setting seeds, but the pollen is fertile and can be used to pollinate other varieties. Some appear to set seeds, but the swollen ovary is empty. Sometimes a good quantity of seeds does not germinate at all.
More frustratingly, after a four-year wait for flowering it may become apparent that the seeds were produced by self-pollination, instead of with the donated pollen. After two generations of this happening using N. watieri as a seed parent, I discovered that the stamens within the flower tube were shedding pollen onto the stigma almost as soon as the flower opened. To counter this I now split open the flower and tube as soon as the bud begins to unfurl, to keep the pollen clear. The same procedure is undertaken with other flowers with a similar structure such as N. rupicola.
As the pots finish flowering, they will be given one or two liquid feeds of half-strength tomato fertiliser (high potash). I do not remove seedheads from the bulbs unless they are known to be ‘nuisance’ seeders, for instance N. romieuxii seeds prolifically into the plunge medium and has to be regularly removed. Most hoop-petticoat types will produce copious quantities of seeds, trumpet types usually fewer, but larger, seeds.
The production of seeds does not affect the subsequent performance of the bulbs, but they remain in growth longer to compensate. For this reason most of my outdoor narcissi are deadheaded so that they will hopefully die back quicker. In order not to miss any of the seeds that are wanted, the seed heads are enclosed in small drawstring bags, sold for such things as wedding 'favours' and jewelry.
If the seed is a result of a deliberate cross, the information label can be put into the bag with the seeds.
I use 7 x 7 x 8cm deep plastic pots for seed sowing, since plunge space is in short supply and unplunged plastic pots are less susceptible to drying out. The seeds are best sown either while they are still fresh, or at any time up until September (ideally) again into a layer of sand halfway down the pot. Unsown seeds are best stored dry at room temperature, not in the fridge, as many will continue to mature throughout the summer.
If there are fewer than about 20 seeds, they are placed together in a small depression in the sand in the centre of the pot, covered with a little more sand, then topped with compost and top dressed with grit. It is essential to label the pot straight away with the identity of the seeds and the date of sowing. If there are a lot of seeds they are sprinkled evenly over the sand layer then topped off as before.
The seed pots are placed in a shaded frame outdoors and given very occasional light watering in very dry weather, otherwise allowed access to any rainfall that occurs. Germination usually begins in September or about the time that the parent bulbs would begin to produce leaves. All the seed pots are brought undercover in October, watered well and stored under the staging. They are checked regularly and any germinated pots are brought up onto the staging in full light.
Seeds obtained in winter can be sown as before, then exposed to the cold weather outdoors for a few weeks before bringing under cover.
LATE SPRING/EARLY SUMMER
Finally, as flowering finishes, the plunges are allowed to dry out as the leaves turn yellow and the bulbs enter dormancy once more. Now is the time for looking at the apparently barren pots and wondering –“Just what is under there?”