Pruning Basics for Small Fruit Production Illinois Specialty Growers, Agritourism, & Organic Conference January 9, 2019

Presented by Ryan Pankau Horticulture Educator University of Illinois Extension Outline

• Basics of Woody Plants

• Pruning Cuts and Plant Physiology

• Pruning Techniques and Objectives • Blueberries • Blackberries

• Q&A The Lifecycle of Woody Plants

• Spring – Leaves emerge • Energy stored in roots is used to leaf out

• Summer – Leaves produce energy • Excess Energy is stored in roots

• Fall – Leaves senesce • All excess energy sent to roots

• Winter – Dormancy The Lifecycle of Woody Plants

• Woody plants have limited resources to support physiological processes

• Resources must be carefully budgeted to maintain plant vigor and productivity

• Pruning and other cultural practices have an impact on that annual budget $ $ $ International Society of Arboriculture 1997 The Lifecycle of Woody Plants • Budgeting strategies change based on conditions

• Example: Woody plant with plenty of soil nutrients • Increase leaf size • Produce larger, thinner leaves • More overall light interception, less photosynthesis/leaf • Maximizes total leaf area • Increase root to shoot ratio • Less root mass needed for adequate nutrient uptake • More energy for shoot elongation

• Example: Woody plant with limited nutrients International Society of Arboriculture 1997 • Decrease leaf size • Produce smaller, thicker leaves • Less light intercepted, but more photosynthesis/leaf • Increase root to shoot ratio • More roots = increased nutrient uptake How Woody Plants Grow

• Primary growth from terminal (apical) bud

• Apical bud imposes “apical dominance” • Apical dominance – hormones (auxin) move down the stem inhibiting grow of lateral buds

• Auxin • Growth hormone • Dynamic distribution throughout plant • Moves downward with gravity

Tennessee Extension 2008 How Woody Plants Grow

• Primary growth from terminal (apical) bud Example: Training Roses • Apical bud imposes “apical dominance” • Apical dominance – hormones (auxin) move down the stem inhibiting grow of lateral buds

• Auxin • Growth hormone • Dynamic distribution throughout plant • Moves downward with gravity

Am. Society of Horticulture 1996 Proper Pruning Cuts

• Always prune to a branch union or bud Branch Collar • Identify Branch Collar

• Make cut just outside branch collar • Allows callus tissue to “seal” over wound • Stubs delay “sealing” process International Society of Arboriculture 2011 Proper Pruning Cuts on Twigs

Tennessee Extension 2008 Proper Pruning Cuts on Twigs

Tennessee Extension 2008 Blueberries

• What produces the best blueberries?

• 2-4 yr old stems • Upper ½ of the shrub • More upright position • Well distributed canopy • 4-7 older stems • 2-3 younger stems

Ohio State Extension 2017 Pruning Objectives

• Understanding objectives is the basis for learning the art and science of pruning

• Pruning objectives vary by: • Species • Tree vs Shrub • Age • Plant Health • Pathogens • Aesthetics • Season Pruning Objectives

• Pruning objectives are similar to the order of operations used to evaluate a mathematical expressions

• Each species has its own “order of operations” for pruning The 1/3 Rule

• Typically OK to prune 1/3 the foliage from a healthy woody plant

• Also applies to individual branches • Helpful estimation tool

International Society of Arboriculture 2011 Pruning Order of Operations Pruning Objectives ≤ 1/3 of Foliage

1. Remove dead, diseased and • 1/3 of foliage/branches can dying limbs typically be removed 2. Establish central leader 3. Remove duplicating stems 4. Remove structurally weak stems 5. Remove crossing stems 6. Improve air circulation 7. Improve ground clearance 8. Remove watersprouts and limbs with weak attachment Blueberries

• What produces the best blueberries?

• 2-4 yr old stems • Upper ½ of the shrub • More upright position • Well distributed canopy • 4-7 older stems • 2-3 younger stems

Ohio State Extension 2017 Blueberries Pruning Objectives 1. Remove diseased, dying, damaged stems 2. Remove stems >4yrs old, adjust age distrib. 3. Remove arching stems • What produces the best blueberries? 4. Remove touching or crossing stems 5. Remove lower, less productive stems • 2-4 yr old stems • Upper ½ of the shrub • More upright position • Well distributed canopy • 4-7 older stems • 2-3 younger stems

Ohio State Extension 2017 Blueberries

Not all varieties are created equal

• ‘Duke’ and ‘Elliot’ are more upright, fewer new shoots • Less pruning to remove arching branches and lower, less productive stems

• ‘Herbert’ is spreading • Additional pruning needed to maintain upright habit

• ‘Patriot’ produces a lot of new shoots • More pruning to thin shoots and remove lower, less productive stems Brambles (Blackberries, Raspberries)

• Root and crowns are perennial, but canes are biennial (only live 2 yrs)

• Brambles bear fruit on 2yr old canes • 1st yr canes – primocanes • 2nd yr canes – floricanes

• Primocane shoots (1st yr) – vigorous summer growth, initiate flower buds in fall, overwinter • Floricane shoots (2nd yr) – fruiting on leafy shoots from lateral buds, canes gradually dry up and die by winter Brambles (Blackberries, Raspberries)

• Root and crowns are perennial, but canes only live 2 yrs

• Brambles bear fruit on 2yr old canes • 1st yr canes – primocanes • 2nd yr canes – floricanes

• There’s always exceptions…… know your variety! • Some brambles fruit twice on the same cane – aka “Everbearing” • Primocanes bear fruits in their tips in the fall (1st yrs) and again further down their stem the following year as floricanes (2nd yr) before dying Brambles (Blackberries, Raspberries) • Pruning practices vary based on growth and fruiting habits and/or trellising system

• Floricane (2nd yr) bearing plants • Blackberries; red, purple and black raspberries

• Primocane (1st yr) bearing plants • Some red and yellow raspberries; some blackberries Blackberries

• Late winter/early spring pruning • Performed prior to bud swell • Select 4-5 vigorous canes to keep • About ½” diameter • Remove all weaker canes to ground- level • About ¼” or less in diameter • Thin lateral branches on remaining canes • Leave about 12-18” in length • Shoot for about 12 -15 buds per lateral • Thin any remaining smaller, new shoots or root suckers from last year • Leave 3-4 of the new shoots Before After Blackberries Pruning Objectives • Late winter/early spring pruning 1. Remove weaker canes • Performed prior to bud swell 2. Thin lateral branches • Select 4-5 vigorous canes to keep 3. Thin new shoots and root suckers • About ½” diameter • Remove all weaker canes to ground- level • About ¼” or less in diameter • Thin lateral branches on remaining canes • Leave about 12-18” in length • Shoot for about 12 -15 buds per lateral • Thin any remaining smaller, new shoots or root suckers from last year • Leave 3-4 of the new shoots Before After Blackberries

• Early Summer pruning • Prune new growth back on primocanes (1st yr stems) • Leave about 4- 6” of new growth -or- • Prune to a specified height (~36 in)

• Post-harvest pruning • Remove all floricanes to near ground level • Promotes development of new shoots • Removes some pest populations Questions?

Ryan Pankau Horticulture Educator University of Illinois Extension

Email: [email protected] Phone: 217-333-7672 Pruning Tools Pruning Tools

• Hand Pruners • Loppers • Cuts up to about 1”, sometimes • Larger cuts, greater than 1” larger • Makes very clean cut • Makes very clean cut • Safer than hand saw • Safer than handsaw • More ergonomic than hand • Essential to smaller pruning jobs pruners • Bypass pruners preferred over anvil-type pruners Pruning Tools

• Hand Saw • Pole Saw • Larger cuts, greater than 1” • Larger cuts, greater then 1” • Turbo-cut blades are very efficient • Available with turbo-cut blades • Clean cut when used properly • Clean cut when used properly • Can be difficult to control, • Sectional poles are versatile opportunity for injury • Consider varying lengths