is an important topic when growing fruit trees
because many - but certainly not all - varieties
require pollination from a compatible donor tree
before they can set fruit.
appears (and probably is) a very complicated
subject. However don't let this put you off - it is
a natural process that almost always "just works".
Some simple rules of thumb:
are in an urban environment you probably won't
need to worry about a pollination partner for
your apple tree - there will usually be
compatible apple trees in neighbouring gardens
and hedgerows. Pears, plums, and cherries are a
bit less widely-planted though, and you can't
assume there will be others nearby, but try
varieties which are not self-fertile, and
require a pollination partner, the partner has
to be a different variety of the
same fruit species. Two trees of the same
variety will not pollinate each other.
are in an isolated area and only want to plant
one tree, choose a self-fertile variety.
doubt, and you have space for more than one tree
of the same species (e.g. 2 apple trees or 2
plum trees), plant two compatible varieties. (If
doing so, it is a good idea to choose varieties
that have different picking times so
that you have a spread of fruit through the
reassured you that pollination is not such a big
issue when choosing what fruit trees to grow, here
are some of the factors that can affect pollination:
terms each species can only pollinate others of its
own kind - apples will only pollinate other apples,
pears will only pollinate pears, and so on.
apples there is generally no distinction between
crab apples, cider apples, and mainstream apples -
they can all potentially cross-pollinate each other.
less clear with plums. European plums (Prunus
domestica) can inter-pollinate with
closely-related species such as damsons, mirabelles
and cherry plums. European plums cannot generally
cross-pollinate with Japanese plums (Prunus
Acid cherries are also different species but can
potentially cross-pollinate each other.
fruit varieties, pollination is carried out by
insects, often bees. Since pollination happens in
early spring, good weather which will encourage bees
is a factor. In the UK and other cool temperate
climates a common problem with species such as
apricots and peaches is that the blossom appears
extremely early, before pollinating insects are
about. (Even though apricots are self-fertile and do
not need a separate pollination partner,
the blossom still needs to be pollinated so lack of
insect pollinators can be a problem).
also depends on having blossom to be pollinated -
which is why the risk of late frosts which can
damage blossom is sometimes a factor. Frosts just
after pollination can also damage the first stages
of fruit formation.
groups / Pollination groups
One of the
easiest and simplest ways to see if two varieties
could pollinate each other is to check their
pollination or flowering groups. The flowering
groups are not the only factor in determining
compatibility between varieties, but they are the
main starting point.
for apples, pears, and most plums and pollination is
most likely to be successful with two varieties that
are in the same group. These groups are somewhat
arbitrary but the concept is simple - each group
contains varieties that flower at around the same
time. Groups may be given letters or numbers, but
they typically run from the earliest-flowering to
the latest-flowering varieties in each species.
neighbouring groups will also work fairly well
because the groups overlap in time. Our variety
pages automatically show you compatible varieties
based on these flowering groups.
- best avoided
authorities record precise dates for the peak
blossom day of each variety. This sounds more
accurate than flowering groups but in practice this
data is not much use and is potentially misleading.
is that flowering dates are different from one
region to another i.e. trees in more southerly or
sheltered regions will usually start blossoming
earlier than those in more northerly climates.
are also different from one year to the next,
depending on the severity of the winter and the
weather during spring. The unusually hard winter
followed by an unusually mild spring of 2011 in the
UK advanced blossom by as much as 4 weeks for some
A more subtle
point is that in continental climates such as much
of the USA, spring is often compressed - the
transition from winter to summer happens very
quickly. In contrast in temperate climates such as
the UK - where much of the original blossom data was
first recorded - the transition is much slower, with
the result that the blossom season is relatively
For all these
reasons, knowing an exact day can be misleading. The
flowering groups, by virtue of being less precise,
are more helpful when comparing different varieties.
and flowering groups
complication is that the rootstock can affect the
flowering times. For example, any apple variety
grafted on the MM106 rootstock will tend to flower a
few days ahead of the same variety on most other
apple rootstocks, whilst the M9 and M25 rootstocks
tend to delay flowering by a few days.
pollinators and poor pollinators
varieties naturally tend to produce a lot of blossom
over a long period, and/or are genetically highly
compatible with a lot of other varieties - this
makes them good pollinators for other varieties.
Most crab apples fall into this category and
commercial apple orchards sometimes inter-plant them
for this purpose.
varieties are very poor pollinators. Bramley's
Seedling is a particular case in point, because it
is a 'triploid' variety which means not only does it
require 2 separate pollination partners, but its own
pollen is ineffective at pollinating other
varieties are self-infertile but there are a few
exceptions such as Red Windsor / Alkmene which are
self-fertile - they do not require a pollination
partner. However, fruiting is usually improved with
a suitable partner.
species such as apricots, peaches, nectarines, the
rule is the opposite - they are invariably
self-fertile so you can safely plant just one
example. However even self-fertile varieties still
need the pollen to be transferred from one flower to
a neighbouring flower and if bad weather deters
pollinating insects the pollination may be poor and
you will get a reduced "fruit set".
Even if all
the other factors are taken care of, sometimes
varieties are still not compatible. This is often
because there is a family relationship. Thus Golden
Delicious - which is an excellent pollinator for
many apples because of the duration and quantity of
blossom - will not pollinate Jonagold or Crispin and
is a poor pollinator of Gala, mainly because these
varieties are closely related to it (very closely
related in the case of Jonagold and Crispin).
relationship incompatibilities operate at a genetic
level and are therefore difficult for the
non-scientist to find out about. However a useful
rule of thumb is that you can usually assume
traditional varieties from the USA are unlikely to
be related to traditional varieties from Europe and
vice versa. Thus Golden Delicious is a good
pollinator for many heirloom European varieties.
This rule breaks down for varieties developed from
the late 19th century onwards though, because by
then transport and communication links had developed
and new varieties were increasingly raised by
research stations and knowledgeable amateurs using
varieties from both continents.
self-incompatibility is a particularly important
issue with the pollination of sweet cherries, and
very complicated to work out. For this reason it is
often best to plant a self-fertile sweet cherry.
In order to
have pollination you have to have blossom ... and in
order to have blossom some of the buds must be
fruiting buds rather than leaf buds. Perhaps
surprisingly, this year's fruit buds are formed the
previous summer. Therefore if you have good
spring weather but little blossom, the cause is
often incorrect pruning the preceding summer.
you can encourage a tree that is not producing much
blossom to create more fruit buds by tying new
branches to the horizontal in early summer - this
fools the tree into thinking that it is fruiting,
and in turn causes it to set new fruit buds (which
will hopefully blossom next spring).
tree pollination compatibility online
ON-LINE POLLINATION CHECKER takes into account
all the above factors and can suggest pollination
partners for a large number of different apple
As we said at
the top of the page, in spite of all the apparent
difficulties, pollination is rarely an issue in