Selecting and Establishing Woody Plants Level 2 – Plant selection & maintenance

What is a Shrub? “A shrub is generally defined as a woody perennial plant with several persistent stems arising from or near ground level”

When is a shrub a tree? According to the American Forests Web site, “... trees are woody plants with one erect perennial stem or trunk at least 250 mm in circumference (75 mm in diameter) at 1.5 m above the ground (breast height), a definitely formed crown of foliage, and a height of at least 4 m.” In contrast, shrubs are small woody plants, usually with several perennial stems branching at the base."

Some reasons for growing shrubs Decorative effect/ seasonal variation Structure Height Permanence Visual and noise barrier, Shelter Dust pollution filtering Creation of habitat, source of food & shelter for wildlife

How can shrubs be used in gardens? Shrub and mixed borders Topiary Ground cover Wildlife and woodland gardens Specimens and mass planting Rose gardens

Trees in the Landscape Advantages and Disadvantages

Advantages & Disadvantages? Divide into groups of 3 or 4 Discuss and then list all the advantages and disadvantages of trees that you can think of After 10 min each group to report back their results

Advantages Provide shade Provide shelter from winds Can frame a view or provide focal point Screen ugly views Help to remove excessive moisture from ground Provide food & shelter for wildlife Provide fruit for human consumption. Absorb CO 2 from atmosphere, release oxygen Provide wood for building, tools & furniture Stabilise soils & prevent soil erosion Provide essential oils for pharmaceutical use Absorb traffic noise

Disadvantages Unwanted shade Leaf-fall and berries need clearing Can damage foundations and drains Block nice views Falling branches can damage & hurt Prevent other plants from growing Harbour aphids that produce honey dew Poisonous flowers / seeds Hazard to motorists Hazard to telephone lines

The right tree for the right place How tall will it grow? How wide will it spread? How vigorous is it? Is it too near the house foundations or drains? Will it cast too much shade? Is it likely to be dangerous to children or motorists? Does it require too much maintenance? Will it thrive in this location?

Water Demand & Foundations Example of tree species High: Oak, Willow, Poplar, Cypress Moderate: Beech, Chestnut, Pine, Sycamore Low: Birch, Holly, Laburnum Area affected by the tree 1.25 x mature height 0.75 x mature height 0.5 x mature height

Selecting and Handling nursery stock plants

Desired Criteria Correctly named Vigorous Good shape Healthy (no damaged or dead wood) Good root system (not spiralling in the container) Pests and Disease free Good value for money

How to choose top quality plants They should be well balanced right down to the ground, Conifers that have bare stems are unsuitable for hedging. Foliage should generally look healthy and not be marked or spotted (sign of P&D) Plants for hedging should not be taller than 60cm/2ft as this will affect the rate of establishment. Check that the compost in the pots is moist, especially for evergreen shrubs.

How to choose top quality plants… Plants should be well established in their containers, with perhaps a little root showing at the bottom. They should not be pot-bound, as this will delay establishment and may affect the development of the root system.

Bare-rooted plants Although most shrubs are now sold in containers some shrubs such as roses and hedging plants can still be bought bare- rooted. Bare-rooted stock is mostly grown to order and used for large scale planting schemes. The main advantage? Main disadvantage?

Root-balled plants Immediately water the root-ball to prevent it from drying out (transportation on an open back lorry can be very stressful). Prepare the site for planting. Make sure to dig out a hole that is at least twice the size of the root-ball in both width and depth. The root-ball will be either wrapped in Hessian, elastic or wire mesh in the case of some trees or just loose in a plastic bag.

Root-balled

Removing wrapping For all shrubs, you should remove all wrapping For trees, Hessian, elastic and even wire wraps will eventually rot away and as tree development is slower they have little or no effect. Inspect the roots for any signs of damage, and prune back with secateurs if necessary.

Planting out Disturb the soil as little as possible then plant to the same depth as that of the nursery or soil mark. Planting too deep may lead to rotting and entry of Pests & Diseases or have the same effect as ring- barking. Plant too shallow and roots will become exposed and dry out

Storing plant prior to Planting If you are unable to plant soon after accepting delivery, then the plants will need to be protected from drying out. Containerised plants can simply be set out on a level piece of ground and kept well watered until needed. Root-balled and bare-rooted plants should be thoroughly watered and then kept in a plastic sack with wet straw, for a few days only, if necessary.

Heeling-in If plants need to be stored for more than one week then they should be ‘Heeled-in’ Dig a shallow pit or trench; place the roots in, cover with soil and firm down with your heels, then water. In this way the plants are give far better protection against drying out and/or frost damage to the roots.