Pruning permanent framework

Transcription

1 Pruning permanent framework Many of these plants form a dome-shaped canopy Generally assume regular shape Ceanothus Julia Phelps Pieris White Cascade Remove: dead damaged Lavender Lavandula spp. Cistus Silver Pink Removal of errant shoots help shape 1

2 Cubist pruning is common Or, the meatball variation Think about flowering time before pruning! 2

3 Shearing removes form, but hopefully not flowers Pittosporum tenuifolium Silver Sheen Arbutus unedo (Strawberry tree) Pruning subshrubs Small subshrubs which may be sheared: have woody base, but bloom on current season s shoots some become larger and more woody in mild climates avoid pruning until after risk of severe freeze Epilobium canum Buddleia nivea Penstemon pinifolius Remove most shoot growth to base Before August 2010 January 2011 After 3

4 Larger subshrubs Caryopteris x clandonensis Spiraea Perovskia atriplicifolia Large subshrubs Remove dead stems, prune hard in spring Buddleia Pink Delight Heptacodium miconioides Lavatera: early spring 10 minutes work! Note where cuts made Later Look how much growth is removed! 4

5 Suckering shrubs Naturally thicket-forming plants Heptacodium miconioides Rhus typhina Laciniata Includes: Aralia spp. Clerodendrum spp. Kerria japonica Rhus spp. Rubus spp. Symphoricarpos spp. Syringa vulgaris Zenobia pulverulenta Dig suckers Use barriers Pruning Conifers For pruning purposes, there are two types: Needle-foliage Conifers: Pine Family Needle-like leaves Whorled branches Scale-like foliage Random branches Abies: The Firs Cedrus: True Cedars Picea: The Spruces Pinus: The Pines Pseudotsuga: Douglasfir Tsuga: The Hemlocks When sited correctly, rarely need pruning The biggest mistake: pruning into un-needled growth Abies pinsapo Glauca Pinus thunbergii Thunderhead 5

6 Pine Family To dwarf plant and fill in canopy, pinch back new growth at candle stage Do not cut into old, un-needled parts of stem! Candle pruning makes a conifer dwarfer bushier Candles on pines are easily broken at this stage Some conifers revert as well Scale-foliage Conifers: Cypress Family Alberta spruce Calocedrus Incense Cedar Chamecyparis Hinoki Cypress Cupressus Monterey, Italian Cypress X Cupressocyparis leylandii Leyland Cypress Juniperus many, many species/forms Thuja Arborvitae, Western Redcedar 6

7 Cypress family plants respond well to light trimming and make good hedges Effects of hard pruning: Don t prune into older un-needled parts of plant! Cutting back hedge Limbing up too-big shrub Conifers that respond to cutting to older wood: Pruning Vines Taxus: Yews Sequoia: Redwood Cryptomeria: Japanese cedar 7

8 Pruning need depends on vigor, climbing habit Consider the climbing habit of the plant: Non-clinging plants: Roses Wisteria rampant growing permanent framework Jasminum x stephanense many thin canes cane-grower Twining growth habit: Clematis Humulus Lonicera Jasminum Trachelospermum Wisteria Clinging vines Tendrils: Ampelopsis Passiflora Vitis Campsis (aerial rootlets) (will also sucker) Hydrangea anomala (aerial rootlets) Hedera (aerial rootlets) Parthenocissus (tendrils) Schizophragma (aerial rootlets) Little or no pruning required The support structure and vine must match! Climbing roses 8

9 A trellis can be very simple Old trees make a good makeshift trellis, too Climbers-modern: very tall bush roses, repeat renew framework regularly Climbing roses Rambling Roses annual cane production train stems flat remove flowered stems thin/shorten excess canes Spreading out stems horizontally encourages branching Climbing Rose: Westerland Modern Climber i.e. blooms on new wood Early spring 9

10 Later Rambling Rose Dorothy Perkins Once-blooming June 2004 Sept July 2005 July 2006 For a full arbor you will need to plant on both sides 10

11 Twining vines Clematis armandii Over time, many twining climbers form a mushroom As with other vines, match the vine with available space Jasminum x stephanense Or, the shape of a TV antenna Young vines: shoot placement 11

12 Lonicera japonica In bloom, June Pruning vining Clematis For pruning purposes, 3 groups based on flowering time: Spring: (Group 1) C. armandii, C. montana Repeat bloom: (Group 2) Large-flowered hybrids C. Nelly Moser After pruning Summer-Fall: (Group 3) C. x jackmanii, C. texensis C. paniculata, C. viticella A simple trellis Pruning vines: Clematis Group 2 (and 1) Pruning Clematis-Group 1 and 2 Remove weak growths Thin stems to well spaced framework 12

13 Pruning Clematis Group 3 Prune low to a pair of strong buds early spring Remove dead stems Pruning Clematis-Group 3 Training Wisteria Trees make handy trellises Brickell and Joyce DK Publishing, 1996 ISBN

14 Brown and Kirkham Timber Press, 2004 ISBN Cass Turnbull Sasquatch Books ISBN Other references: PlantAmnesty Pruning tips PNW-International Society of Arboriculture Pruning information Publications Lists of Consulting Arborists The End! Pruning Rhododendrons and Azaleas Ceanothus griseus Kurt Zadnik 14

15 Rhododendron stem and bud structure Pruning Rhododendrons and Azaleas Removal of spent flowers promotes branching Prune after flowering-remove leading branches at a whorl Pruning should be done over a 2-3 year period Prune above a whorl of leaves to avoid leaving a stub The too-big Rhododendron correct incorrect Be careful about shearing 1. Make it a focal point! 2. Too big or too dense? remove dead wood, thin branches 15

16 3. Shorten tallest branches cut to lower laterals 5. Turn it into a small tree on old, large specimens, remove lower limbs, dead wood, thin canopy 4. Remove all new growth time consuming! 6. Renovation cut plant to ground poorly pruned shrubs Some years later Pruning Hydrangea Recall that pruning time will vary with the species! H. macrophylla: Remove spent flowers Thin 1-2 canes H. macrophylla =previous season H. paniculata =current season H. paniculata treat like subshrub Cut canes to 2 buds 16

17 Remove flower heads Remove oldest cane(s) Hard pruning of H. macrophylla in spring Pruning Roses hybrid tea =Reduced flower number 17

18 Once versus repeat flowering Refers to whether a rose bears flowers on one-year-old wood (once-blooming) current season wood (repeat blossoming) Hybrid Tea, Grandiflora, Floribunda Roses like all other roses, these are cane growers remove dead canes oldest canes may be cut out leave 3-4 canes space around plant cut back to 18-2 Once blooming: June Repeat bloom-all summer Sucker removal 1. Late summer 2. Fall 3. mid-february 4. mid-february The final product 18