PEAR TREE ROOTSTOCKS

If you grow a pear tree from a seed and leave it to grow on its own roots you will end up with a massive tree which can easily reach 6m to 7m (20ft to 23ft) high. The fruit will be well out of the reach for picking unless a ladder is used, it will cast a large amount of shadow and will suck up moisture and nutrients from a wide area. Another, often ignored, problem with large pear trees is that they are difficult and sometimes impossible to spray with pesticides. These disadvantages are not the ideal for almost all UK gardeners!

Pear tree growers, both commercial and amateur, were provided with an ideal solution to tall growing pear trees in the mid 1920s when East Malling Research made Quince rootstocks available to the general public. A rootstock is a variety of tree which restricts the size and enhances the growth characteristics (disease resistance, fruit size and shape, survival in adverse conditions) of pear trees when they are grafte  onto it. Currently, the vast majority of pear trees commercially grown in the UK are on Quince C or A rootstocks.

The picture below shows the rootstock at the bottom of tree where the roots are growing into the ground. The scion is the desired pear tree  variety which has been grafted onto the rootstock at the point shown by the join

Different areas in the world have preferences for different rootstocks because local conditions differ and require a rootstock which does best in those conditions. In the UK the following rootstocks are commonly available to the amateur gardener:

1. Quince C Rootstock

   : this is a quince tree (closely related to
   the pear tree) rootstock which is the most dwarfing (i.e. restricts the
   eventual height of the tree) of all. Trees grown on this rootstock
   typically grow to a mature height of 2.5m to 3m (8ft to 10ft) depending
   on the variety and local conditions. Pear trees grown on the Quince C
   rootstock have the following characteristics:

   • Suitable for growing as a bush, cordon, espalier and fan shaped
     tree
   • Begins to produce fruit quickest of all, normally after three to
     four years
   • Requires a stake to support it throughout its life
   • Best grown in soils which have good supplies of water (not
     water-logged) and nutrients.
   • Does not do well on alkaline
     soils.

2. Quince A Rootstock:

   this is also a quince tree rootstock
   which is slightly more vigorous compared to Quince C. Tree grown on this
   rootstock typically grow to a mature height of 3m to 3.5m (10ft to 11ft)
   depending on the variety and local conditions. Pear trees grown on the
   Quince A rootstock have the following characteristics:

   • Suitable for growing as a bush. Can also be grown as a bush,
     cordon, espalier and fan shaped tree on poor soils
   • Begins to produce fruit after four to five years
   • Requires a stake for the first three years of its life
   • Grows well on most soil conditions.
   • Can easily be pruned to a height of 2.4m / 8ft. This is the
     rootstock we recommend for most garden situations.
   • Does not do well on alkaline
     soils.

3. Pyrodwarf Rootstock:

   this rootstock is not dwarfing in the
   true sense of the word. It is a cross between two varieties of Pyrus
   communis (‘Old Home’ בBonne Luis d’Avranches’). Pyrodwarf is of
   German origin and is copyrighted. Trees grown on this
   rootstock typically grow to a mature height of 4m to 4.5m (13ft to 15ft)
   depending on the variety and local conditions. Pear trees grown on the Pyrodwarf rootstock have the following characteristics:

   • Suitable for growing as a standard or half standard. Can also be
     grown as a large fan or espalier on poor soils
   • Begins to produce fruit after four to five years
   • Does not require staking
   • Grows well on most soil conditions
   • Produces lots of suckers from the rootstock which should be pruned
     away
   • Good resistance to fireblight which can be a major problem with
     pear trees grown in warm areas of the UK
   • Tolerates alkaline soils better than most rootstocks
   • Currently not very commonly offered for sale in the UK.

4. Pyrus communis Rootstock:

   this is a rootstock which
   is grown from a seed. If you want a large pear tree it is still better
   to grow it on a rootstock because it will, in most cases, give the tree
   better disease resistance and fruit production abilities. Trees grown on
   this rootstock typically grow to a mature height of 6m to 7m (19ft to
   23ft) depending on the variety and local conditions. Pear trees grown on
   the Pyrus Communis rootstock have the following
   characteristics:

   • Suitable for growing as a standard
   • Begins to produce fruit after eight to ten years
   • Does not require staking
   • Grows well on most soil conditions and tolerates alkaline soil

It’s clear that the rootstock of a pear tree is the most important factor
in its final size. Our recommendation for most amateur gardeners would be to
choose the Quince A rootstock. For smaller gardens its size can be further
reduced by an annual prune in June. Quince C may be
more suitable in the following conditions:

• In small gardens where space is at a premium
• In small and medium sized gardens where the soil is a rich loam and
  has a good water supply and the tree will be in full sun position all
  day
• Where fireblight is a known problem, consider also the Pyrodwarf
  rootstock for fireblight resistance (see above).

PEAR TREE HEIGHT – OTHER FACTORS

After the choice of rootstock, local growing conditions are the most important
factor as far as tree height is concerned. Pear trees thrive in a rich loam soil
that has good drainage but at the same time a regular supply of water. They
also grow better (and produce more fruit) in a full-sun position for as much
of the day as possible.

FORMS AND SHAPES OF PEAR TREES

Trees can be grown in all shapes and forms but the most common pear trees in
the UK for amateur gardener are as follows:

• Bush shape: A bush shaped pear tree is the most
  common in UK gardens. Typically the bare trunk will be about 60cm / 2ft
  and the total height at maturity (on a Quince A rootstock) will be about 3m to 3.5m (10ft to
  11ft). Of all the shapes this one is the easiest as far as
  pruning is concerned.
• Fan shaped: Almost always grown against a wall.
  Initially the tree is pruned so that two main stems are grown in a V
  shape and from those a series of two side-branches are grown and tied
  onto the wall. The bare trunk will be about 30cm / 1ft and the total
  height at maturity (on a Quince A rootstock) will be about 2.5m to 3m (8ft to
  10ft). To create the ideal shape the tree not only needs to be pruned
  carefully but the individual branches need to be trained to the correct
  shape. Difficult to achieve and time consuming but very productive of
  fruit, utilises space very efficiently and looks spectacular. See the picture below.

  

 

• Espalier shaped: The shape is a single stem with
  pairs of branches growing from it in tiers. The bare trunk will be about
  30cm / 1ft and the total height at maturity (on a Quince A rootstock) will be about
  2.5m to 3m (8ft to
  10ft). The most difficult shape as far as pruning and training is
  concerned. Very productive and forms a spectacular centre-piece.Awaiting picture
• Cordon shaped: The shape is a single stem with very
  short side branches. The bare trunk will be about 30cm / 1ft and the
  total height at maturity (on a Quince A rootstock) will be about 2.5m to
  3m (8ft to 10ft) although careful pruning can restrict the height. Each
  individual cordon will produce far fewer pears than other forms but
  because the trees occupy so little space more can planted in a given
  area. Require a wall, fence or strong structure to support them.

PEAR TREE POLLINATION

The majority of pear tree varieties are self-sterile which means they need
another variety (not the same variety) nearby which flowers at the same time
for pollination to occur. Only when pollination occurs will fruit begin to
form. Two common varieties which are considered self-fertile (i.e. they do
not need a pollination partner) are Concorde
and Conference. In most conditions they
will produce a crop of pears as stand alone trees.

Pear trees are pollinated by bees and a few other insects but in reality you
are relying on bees. In most suburban and urban gardens there is a likelihood of a suitable pear tree(s) for pollination being grown nearby but
this is by no means guaranteed. Remember, far fewer pear trees are grown in the UK compared to
apple trees and this can make pollination of a single pear tree problematic in many areas.

To guarantee success you need to grow two matching pear
tree varieties in your garden and the two trees shouldn’t be of the same
variety. The only other consideration is that they must flower at roughly the
same time. Pollen is produced in the flowers and matching flowering times is the
key to successful fruit production.

If only life was that simple! Various companies and organisations have
tried to group pear tree varieties into what is called pollination groups.
The theory is that varieties of the same group will pollinate each other
because they flower at the same time. In practice a given variety will also
pollinate others in groups next to them as as well. Take the example of
Conference pear tree which is in pollination group 3; it will be not only be
capable of pollinating other varieties in group 3 but also groups 2 and 4.
This is because the flowering time of a pear tree is roughly three weeks and
therefore varieties in different groups can overlap each other as far as
pollination is concerned.

The first complication occurs because some organisations do not use
“numbers” to define pollination groups, instead they use letters and the two
do not necessarily correspond. Even comparing the “numbering” system,
different organisations use different numbers for the same varieties.

Take the case of the variety Beurre Hardy. The
RHS classify it
as being Group 3,

Ashridge Trees classify it as being Group B,

Keepers classify it as being Group D (and also uniquely classify it as
“Pollination Date 19”),
Blackmoor
classify it as Group B,

Chew Valley go out on a limb and classify it as “mid-season flowering”,
the differences in classification goes on and on.

What seems very strange to us is that none are specific about the
dates when a variety will, on average, be in blossom. Possibly this
is because each year has different weather conditions which can
significantly delay or bring forward the dates of blossom. But this is not a
problem in reality as the following example shows. Let’s say we agree that
the average date, in the average UK area, for Conference producing blossom
is the third week of April through to the first week of May.

In a good year weather wise this date might be brought forward by a week
or two. But the critical point is that if Conference flowers two weeks
earlier than normal so will all the other varieties of potential pollination
partners, so pollination will not be affected. With this in mind, our unique
table below shows two pollination date classifications for all the common
pear tree varieties. The RHS classification and a date when, on average, you
can expect blossom production to be at its peak.

We suggest you personalise the results to the weather in your home town
by clicking here. This
will make the dates as accurate as possible. It only takes a minute and will
cause all dates on this site to be accurate for your home town. The setting
will last for six months or more and can be checked by looking at the top of
every page where your home town setting is clearly displayed.

PEAR POLLINATION GROUP 1

Varieties in this group will pollinate others in groups 1 and 2:

There are no common varieties of pear trees in  group 1.

PEAR POLLINATION GROUP 2

Varieties in this group will pollinate others in groups 1, 2 and 3

Louise Bonne Jersey	Average flowering date:April week 2 (UK average)
Invincible	Average flowering date: April week 2 (UK average)

Notes: Louise Bonne of Jersey and Williams' Bon-Chretien are not compatible Invincible produces a second flush of blossom three weeks later in cold conditions.

PEAR POLLINATION GROUP 3

Varieties in this group will pollinate others in groups 2, 3 and 4 

Beth	Average flowering date: April week 4 (UK average)

Beurre Hardy

Average flowering date: April week 4 (UK average)

Catillac

Average flowering date: May week 1 (UK average)

Clapp's Favourite

Average flowering date: May week 1 (UK average)

Concorde

Average flowering date: May week 1 (UK average)

Conference

Average flowering date: April week 4 (UK average)

Durondeau

Average flowering date: April week 3 (UK average)

Glou Morceau

Average flowering date: April week 4 (UK average)

Gorham

Average flowering date: May week 1 (UK average)

Merton Pride (triploid)

Average flowering date: April week 3 (UK average)

Packham's Triumph

Average flowering date: April week 3 (UK average)

Williams' Bon-Chretien

Average flowering date: April week 4 (UK average)

Winter Nelis

Average flowering date: April week 4 (UK average)

Notes: Williams' Bon-Chretien and Louise Bonne of Jersey are not compatible Triploid varieties (Merton Pride) cannot pollinate other any other pear trees, they are also self-sterile.

PEAR POLLINATION GROUP 4

Varieties in this group will pollinate others in groups 3, 4 and 5  

Beurre Bosc

Average flowering date: May week 2 (UK average)

Blickling

Average flowering date: May week 2 (UK average)

Doyenne du Comice

Average flowering date: May week 4 (UK average)

Onward

Average flowering date: May week 2 (UK average)

Notes: Doyenne du Comice and Onward are not compatible

BARE-ROOTED OR CONTAINER GROWN PEAR TREE?

Pear trees are sold as either bare-rooted or in containers. A bare-rooted
tree will have been grown in open ground at a plants nursery and then dug up
when it is dormant, November to February are typical times. Almost all the
soil is removed from the roots, they are then packed ready for sale either
to direct customers or via the internet. The first key advantage of a
bare-rooted pear tree is the lower cost compared to a container grown tree.
This is especially the case when buying over the internet because the
postage costs will be far lower. Another advantage is that more varieties
are grown as bare-rooted trees giving you a bigger choice.

The disadvantage of a bare-rooted pear tree is that they are normally only
available for sale during the months November to early March because they must
be dormant at the time of sale.

Container grown pear trees have the single advantage that they can be
sold and planted at any time of the year. They are normally, however, more
expensive and the choice is restricted.

PLANTING AND CARE OF YOUR PEAR TREE

Click here for full details of how to plant and care for your pear tree.
We explain in detail how to plant both bare-rooted and container grown
trees, how to stake your tree if necessary and ongoing care throughout its
life.