At a glance
Mistletoe is a parasitic plant that grows on the branches of host trees, drawing water and minerals from them while producing its own food through photosynthesis. It cannot be grown in soil and depends entirely on a living host tree to survive. In UK gardens it is most commonly found on apple trees, though it will also grow on lime, hawthorn, poplar, willow and field maple. In winter, when the host tree has shed its leaves, mistletoe becomes its most visible: rounded globe-shaped masses of pale green growth in the canopy, covered in white berries from October onwards.
Growing your own from seed is the only reliable way to establish mistletoe on suitable host trees. It is protected under the Wildlife and Countryside Act 1981, which means uprooting it from the wild is illegal. Sowing it yourself in the garden is entirely legal, and with a suitable host tree and patience, consistently achievable.
What mistletoe is
Mistletoe is a semi-parasitic evergreen shrub. The stems fork repeatedly into a distinctive ball shape, reaching up to one metre across on a well-established plant. The leaves are oval, pale yellowish-green and arranged in pairs. The plant is dioecious, meaning male and female flowers are produced on separate plants. Only female plants produce berries, and only when a male plant is nearby for pollination. The flowers are tiny, green and appear in February and March, easily missed but important because this is when pollination occurs.
The white berries are a valuable food source for mistle thrushes and blackcaps, birds that have evolved specifically to feed on them. In the wild, these birds spread mistletoe by wiping seeds onto branches or passing them through their digestive system. In the garden, you replicate this process manually.
Which host trees to choose
The host tree is the single most important factor. Mistletoe is highly selective and will fail on unsuitable trees regardless of how carefully the seeds are sown. The table below rates the most common options.
The tree must be reasonably mature and in good health. Very young trees with smooth, thin bark are poor candidates. The tree must also receive good light, as mistletoe is a sun-loving plant and will fail in deep shade even on an otherwise suitable host.
When and how to sow
Timing and technique both matter. Sowing at the wrong time or with dried-out seeds is the most common reason attempts fail before they have even begun. The steps below set out the correct process.
Do not cut or nick the bark before sowing. Some older guides recommend making a small wound in the bark. Current advice is firmly against this. It risks damaging the branch, disrupts the tree’s wound responses, and can introduce fungal infection. Simply press the sticky seed onto the surface.
How long it takes
Mistletoe is extraordinarily slow to establish. Patience is not optional. The table below shows what to expect year by year and why so many attempts are abandoned prematurely.
Managing established mistletoe
Once established, mistletoe requires almost no intervention. It manages its own growth rate in relation to its host and does not need watering, feeding or any conventional care. The only management decisions involve keeping the plant in balance with its host. A tree carrying dozens of clumps will eventually suffer from the combined draw on its water and mineral supply, particularly in dry summers. On apple trees that are also meant to produce fruit, excessive mistletoe burden can reduce cropping significantly.
Manage this by removing individual clumps where the overall load is becoming heavy. Cut clumps back to the branch they grow from. The internal haustorium within the branch remains, so regrowth will occur. This is normal. Repeat as needed over several years to keep the balance manageable. The best time to remove or trim mistletoe is after the berries have set in autumn and before new growth begins in spring. If harvesting stems for seasonal decoration, cut cleanly in November or December and the remaining plant will regrow from the attachment point.
Encouraging berries
Only female mistletoe plants produce berries. Male plants are needed nearby to provide pollination but produce no berries themselves. Plants cannot be sexed before they flower, which they typically do not do for several years after establishment. The only practical approach is to establish multiple plants to improve the chance of having both sexes present.
Pollination occurs when small insects visit the tiny flowers in February and March. Cold, wet, still weather during this brief window can result in poor pollination and no berries even when both male and female plants are present. This is not a failure of the plants but a weather-dependent outcome, and the following year may produce a full crop.
Sow seeds from multiple sources on multiple branches. You cannot control the sex of plants you establish, and you need both to get berries. Sowing generously over several branches of the same tree, and ideally on more than one tree, maximises your chances of ending up with a male and female in close enough proximity for pollination.
Toxicity
All parts of mistletoe are toxic to people and animals. The berries in particular should not be eaten. Symptoms of mistletoe poisoning include nausea, vomiting, and can affect heart rate and blood pressure. Fatal poisoning from casual contact with berries is extremely rare, but all parts should be treated as toxic and kept away from children and pets. Wear gloves when handling cut stems and berries, and wash hands afterwards. The sticky sap can cause skin irritation in sensitive individuals. Despite traditional medicinal uses of mistletoe in diluted preparations, the berries should always be treated as toxic in a domestic setting.
Common problems
Most problems with growing mistletoe come down to the same handful of causes. The table below covers each one with what to do.
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