Why didn’t my daffodils appear?
Q What has happened to my containers of daffs? Mike Crossley, Gillingham, Kent
A There’s nothing worse than planting up a collection of bulbs in the autumn in expectation of a great show in the spring, only to find the shoots barely make it out of the ground. Where bulbs fail to sprout or produce yellow and distorted foliage, there are a number of possible causes.
Daffodils are usually very reliable but I’d avoid using multi-purpose compost in a container, as over winter pots can get waterlogged. While daffs like moisture, they don’t want it wet, which could lead to root rot. Either, place containers where they have some overhead protection from the rain, or incorporate a good amount of horticultural grit in mixes to give good winter drainage.
Avoid reusing potting composts from the previous year, too. The organic component decays over time, and the compost slumps and loses its structure, becoming airless and poorly drained. Commercial growers base their choice of potting composts largely on something known as the AFP – air-filled porosity. Particularly for long-term plants, they want a relatively coarse mix with lots of air spaces to encourage good drainage and strong root growth.
The other problem with old potting compost is that the risk of disease is greater.
Looking at the photograph, I suspect infection by narcissus basal rot ( Fusarium oxysporum) may be the cause of the poor performance. Decay sets in around the base of the bulb and the roots fail to develop. A shoot may start to grow from the resources within the bulb, but it quickly falters with no roots to sustain further growth. Tiny worm-like creatures may then invade the decaying tissue.
When saving bulbs from year to year, clean them carefully, discarding any that are soft or showing signs of damage.
If you cut the bulbs across and see a series of brown rings or arcs this could indicate infection by stem and bulb eelworm ( Ditylenchus dipsaci) a microscopic nematode. Commercial growers use hot water treatment to destroy the eelworms but it’s difficult without professional equipment. For the home gardener the best option is to remove all infected plant material and dispose with household waste.