Speaker – John Hill – Commercial Horticulture
John Hill has been in the commercial horticulture years for 57 years. He moved from
Saltburn to Stokesley at the age of 22. John has been running the family business for 16
years and his sons are the 4th generation to have worked in the company. John gave a very
interesting talk with many slides giving insights into an industry that is probably very different
from any that most Members are familiar with.
He described horticulture as ‘the science or art of cultivating plants’. Many plants have
common, but all have Latin names. The common names may vary between countries, but
the Latin name is consistent worldwide.
Wholesale nurseries are invariably specialists in one area of horticulture. For example,
strawberries may be grown as field or hydroponic and either outside or inside. Nurseries
may grow tomatoes or just produce seedlings. Artificial lighting can be used to produce
plants for sale at unfamiliar times of the year by adjusting the length of the ‘day’.
Trees may be grown for sale in various sizes and states. For example they may be 1 year
seedlings, 1 year seedlings transplanted for 2 years, 2 year cuttings and many others. All
these different varieties are produced to suit the requirements of buyers.
John’s company has a database of 30,000 different categories of plants on its database,
which is used when quoting to buyers. Because every company specialises, supplying a
customer’s requirements often requires quotations and trading between nurseries.
Container grown trees may be grown in bag pots or air pots. Air pots produce a better
fibrous root system, because when a root grows out of the side of an air pot, the effect is the
same as pruning it mechanically. Trees are irrigated with a dripper system. Feed is also
delivered this way. Compost may be made with peat or coir. Bark is often added to peat.
Fertiliser is often provided in a controlled release form as granules. The granule coating
controls the rate of release, which can be influenced by moisture and temperature. An
agronomist may be employed to advise on the Dosatron settings.
Compost mixing used to be done in house, but now it is bought in. The compost is produced
to Hill’s specification and brought bagged to the nursery. The potting process is highly
mechanised and completes 1000 pots of 2 litres per hour.
Bugs and grubs can cause serious damage to young trees and vine weevils have been a
nuisance in Stokesley. The adults eat leaves in the spring and summer and the grubs eat
roots in autumn and winter. Traditional chemical treatments are now banned, but insect
parasitic nematodes can control them. Unfortunately, these usually die in winter and so they
have to be reintroduced every spring.
Tree production is highly mechanised. A 4 wheel drive and 2 wheel steer platform is used for
pruning the tops of trees. Even tying trees is mechanised. A soil balling machine is used
when lifting larger trees. These are expensive and their handling must be done in a way
which reduces damage to negligible levels.
In reply to questions, John said that Hill’s guarantee that trees are delivered in good health.
They cannot control how a tree is treated after delivery, but they try their best to satisfy the
customer. Tree seeds may take a year to germinate, but putting them in a fridge may speed
the process up by tricking them into thinking that it is winter.