Mulberry    Trees

Mulberry Tree - Propagation

Mulberry trees are not terribly dificult to propagate.

However black mulberries appear to be domesticated - and probably only reproduce in England with human assistance. I have yet to witness a black mulberry sapling growing naturally anywhere near the base of its parent.

Mulberry trees are slow-growing - which means that propagation efforts will typically not bear fruit for many years.

Plants 2-3 years old

Propagation can be done via seeds or cuttings.

Seeds have the advantage of ensuring the young plant has few pathogens.

However, cuttings allow a tried-and-tested genotype to be used.

Young seedlings

Seeds can be obtained for common mulberry varieties directly from fruit - or from the internet.

If fresh fruit is the source, cleaning the flesh from seeds is tedious - but needs to be done to prevent moulds forming.

Seeds are supposed to benefit from cold stratification - however they germinate pretty well without it, at any time of the year - if provided with suitable conditions.

I clean the seeds, bury them seeds under about 1mm of purchased compost in the illustrated containers, put them in a heated incubator and keep them moist.

Some seeds germinate later indoors without heat - if left long enough.

The germination rate is reasonable, and the infant mortality rate is fairly modest.

It has been suggested - in a paper entitled "Does Ingestion by Birds Affect Seed Germination?" - that Morus Nigra seeds germinate better after passage through a bird's gut. However, they seem to germinate reasonably well without this treatment.

Mulberry seedlings have relatively fragile roots, and these are easily damaged while pricking the seedlings out. It seems best to prick them out as soon as the first signs of germination appear - if space permits.

Plants outside in pots

In England, the next problem is the first winter. Established specimins can be put outside to winter - however more recent seedlings that have not yet developed a woody stem may need to be kept under glass. If they do not actually freeze, mulberry seedlings become dormant in the winter - but do not lose their leaves.

If they survive the winter, another common problem is extended dormancy. Mulberries put their tasty leaves out tentatively, and drop them at the first sign of frost. They spend much of their time in a dormant state - and sometimes they do not wake up. This is a fairly common problem - affecting perhaps 20% of seedlings. I lost my very first mulberry seeding after two and a half years due to this problem.

There is often a solution: brutal surgery. If a mulberry is still dormant by the start of summer it will probably stay that way permanently - if left to its own devices. Fortunately, dormant mulberry seedlings can often it can be brought back to life - by chopping off their top along with any existing leaves. The cut should be made above the most promising-looking bud. Cutting close to the ground is OK.

Such surgery apparently sends the plant into an emergency state - where it heavily prioritises putting out new foliage. It often seems to be enough of a shock to wake up a dormant plant.

After six months or so, plants should be placed in pots outside. After a year or two, they may be transplanted to their proposed location - unless this is frequented by deer, or other large herbivores.

Various ants may attack and destroy mulberry seedlings. In particular, the yellow meadow ant - Lasius flavus - will happily move into the moist basement of a mulberry seedling, plant its sap-sucking aphids on the roots, and suck the plant dry until it is dead. This is a relatively common fate of mulberry seedlings, in some areas. I recommend the use of ant powder. Also - if possible - avoid planting out near existing Lasius flavus nests.

Note that some young mulberry plants exhibit an unusual lobed leaf shape. This is perfectly normal - and does not indicate any genetic abnormality.

Because mulberry trees are so slow to grow, they may need their light defending against faster-growing neighbours for many years - if they are to survive and thrive.

Mulberry trees may also be propagated vegetatively.

There is a separate page about that here.

Tim Tyler | Contact |