1. RHS Level 2
Certificate
Week 25 – Ornamental trees
and shrubs
This Photo by Unknown Author is licensed under CC BY-SA
2. Quiz
• 10 questions – 15 minutes
• Use the Week 26 Quiz on Moodle –
don’t forget to save and submit at the
end.
• Please put your notes away.
3. Learning objectives
3. Understand the choice of woody plants for display and their
establishment and maintenance.
3.1 Name TEN trees suitable for growing in a domestic garden
3.2 Name TEN shrubs suitable for growing in a domestic
garden.
3.3 Name FIVE trees grown for winter interest and FIVE grown
for autumn display.
3.4 Name FIVE shrubs grown for winter interest and FIVE grown
for autumn display.
3.8 Describe the soil preparation and planting for trees and
woody shrubs.
3.9 Describe the routine maintenance for trees and woody
shrubs, to include pruning and the control of weeds and
common pests and diseases (aphids, powdery mildew, black
spot of roses, canker, coral spot, honey fungus).
4. Selecting Trees and Shrubs
• ‘Anchor plants’ – providing structure
and interest all year round.
• Be aware of final size and spread –
allow for the mature size when
planning planting.
• Forest trees do not belong in small
gardens!
• What season of interest?
• What type of plant - Bare root,
container-grown or containerised?
5. Bare root, containerised or
container grown?
• Bare root – plant in Autumn/Winter. A narrow
window for planting and only small plants available.
However: cheapest method, and small plants often
establish better than large ones.
• Containerised/root balled – can be planted at any
time of year and you can see what you are getting.
Disadvantages – possible limited root system, may
become pot bound.
• Container grown – most expensive, plant at any
time of year (provided you water them). May
become pot bound before sale. Large specimens
may not establish well.
This Photo by Unknown Author is licensed under CC BY-NC
6. Buying a healthy plant
• Check for dead, diseased or distorted
growth and any signs of pest infestation or
fungal problems. Signs of nutrient
deficiency suggest it has been in its pot too
long.
• If the compost is very dry this suggests lack
of care.
• Avoid pot-bound woody plants. Look for
large amounts of root growing through the
base of the pot and algae or moss on the
surface.
• Look for a good shape and balanced growth
– an ‘ugly’ tree will be very hard to correct.
7. How to
plant trees
and shrubs
– changing
practice
Old approach was to enrich the soil in the
planting hole with compost and fertilizer.
However, this can encourage the roots to
remain in the hole.
Poor soil should be improved in a wide area
around the site before planting instead.
Previous advice was to dig a deep hole. Danger is that
this slumps taking the tree too deep. Current thinking
is – wide but not deep.
8.
9. How to plant (1)
If soil is poor improve the whole area. Consolidate and leave to settle.
Hole - 2-3 times the width of the root ball but only slightly deeper.
Square holes – encourage root penetration.
Fork over the bottom and sides of the hole. Add mycorrhizal fungi if
using- do not mix.
Remove plant from container and tease out roots.
If planting bare root plant - untangle the roots, trim any broken ones.
Spread out the roots in the hole.
Take care not to plant too deep – identify the ‘nursery mark’ or surface.