Daffodil

Light and exposure

Daffodils like sun but cope very well with partial shade, which makes them one of the few bulbs that thrive under deciduous trees. By the time they flower, at the very start of spring, the branches overhead are still bare and plenty of light reaches the ground, even under a big oak or an apple tree.

Once flowering is over, the growing shade cast by the trees’ leaves is no problem at all, because daffodil foliage finishes its cycle before summer arrives. That is exactly what allows it to naturalise in woodland edges or lawns, where almost no other bulb flower settles in so easily.

Watering

In open ground, daffodils get by on rainfall alone and need almost no watering at all. A bulb planted in autumn draws on reserves in the soil through winter and only needs a helping hand in an exceptionally dry spring, while the foliage is still green and active.

In a pot, things are different: the compost dries out faster, and regular watering in spring stops the bulbs coming under stress while in full flower. Once the foliage has died back, though, stop watering altogether: the daffodil goes into summer dormancy and hates wet feet at that time, since too much water in summer easily rots the bulb.

Soil and repotting

An ordinary garden soil suits daffodils fine, as long as it drains well. They grow in most soils, including fairly heavy clay, as long as water does not sit around the bulb in winter.

On very heavy, compacted clay, loosen the soil to a good depth before planting and work a little coarse sand or well-rotted compost into the bottom of the hole. In a pot, an ordinary potting mix lightened with a bit of sand and good drainage at the base is more than enough.

Temperature and humidity

Daffodils are fully hardy from USDA zone 3 to zone 8 and shrug off even the harshest frosts, the bulb sitting safely under some fifteen centimetres of soil. In fact the bulb needs that winter cold to trigger flowering the following spring, a natural mechanism known as vernalisation: count on twelve to sixteen weeks below seven degrees.

That is exactly why you should never bring daffodil bulbs indoors for winter the way you would a dahlia or a tuberous begonia: without enough cold, the plant will not flower well, or at all, the following year. Just leave them in the ground, that is what they are built for. In a mild climate, where winter never drops low enough, the logic is reversed: you give the bulbs ten to fifteen weeks in the fridge before planting them.

Pruning and upkeep

Deadhead the spent flowers as they fade, cutting only the flower stem, to stop the plant wasting energy on setting seed. This simple habit feeds straight back into the bulb, which rebuilds its reserves for next year.

The most important point, and the one most gardeners get wrong: let the foliage yellow and die back completely before cutting it, which takes around six weeks after flowering. During that time the still-green leaves are recharging the bulb through photosynthesis. Never tie the leaves into a knot or braid, and never mow them while green, however untidy it looks on the lawn, that is the surest way to weaken the bulbs year after year.

Pests and diseases

The narcissus bulb fly (Merodon equestris) is the main pest: its larva burrows into the bulb and eats it from the inside, leaving stunted plants with thin, sparse leaves, or bulbs that simply fail to come back. You usually only spot it in hindsight, finding a soft, hollow bulb when you dig one up.

Bulb rot, caused by Fusarium fungi, takes hold mainly in waterlogged or poorly drained soil, turning the bulb brown and soft underground. The good news: unlike tulips or crocuses, daffodils hold no interest for field mice or voles, which avoid them because of their toxicity, and that cuts losses to below-ground pests right down.

Propagation

Dividing clumps is the simplest and most reliable method. Every three to five years, once a clump flowers less freely or produces smaller blooms, a sign it has become overcrowded, dig it up after the foliage has died back fully in summer, separate the bulbs by hand and replant them straight away, spaced well apart.

Daffodils also produce small offset bulbs naturally around the parent bulb, tiny bulbs that will bulk up and flower within two to three years. This is exactly the mechanism behind their spontaneous naturalising in lawns: left undisturbed, a clump of daffodils spreads on its own, year after year, without any input from the gardener.

Toxicity

The whole plant, and especially the bulb, contains toxic alkaloids, including lycorine. The bulb can easily be mistaken for an onion, and poisonings happen fairly regularly when it is picked up for cooking by mistake, causing nausea, vomiting and stomach pain. The sap can also irritate the skin when handling bulbs or stems, particularly for sensitive people, so it is worth wearing gloves when planting or dividing large quantities.

Month-by-month care calendar

Green Hub tips

• Never cut back the green foliage after flowering: let it yellow and die down completely, around six weeks, that is what recharges the bulb for next year.
• Plant bulbs at a depth of roughly three times their height, pointed end up, six to eight weeks before the first autumn frosts.
• Let clumps naturalise in a lawn or under trees: daffodils multiply on their own and come back thicker every year with no upkeep at all.
• Unlike tulips, daffodils are left well alone by field mice and voles thanks to their toxicity, a real advantage anywhere those rodents go after bulbs.