Pruning South Florida Native Trees and Shrubs

Presented at the South Florida Native Plant Seminar October 18-19, 2023 Naples Botanical Garden

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Pruning South Florida Native Trees and Shrubs Donna Corbelli Castro Education Specialist 2023

Pruning Matters Pruning has always been one of those topics that confuses even the most experienced landscapers and horticulturists.

Why the mystery?

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Pruning is both a science and an art.

Ask three arborists where to cut, and you are likely to get 3 different answers .

To Prune or Not to Prune…

Pruning

That is the question!

• Why do we need to prune?

• When do we need to prune?

• How do we prune?

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Why Should We Prune?

Structural Pruning is the most important aspect of pruning .

Should always be clear objectives Nursery Growers should NOT top trees.

Topping will destroy apical dominance and create co-dominance Nursery growers should discourage circling

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Why Should We Prune?

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Vista Pruning Size, Shape, Style Strive for natural shape of species, many native trees are naturally multi-trunked

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Why Should We Prune? .

Correct structural defects Remediate past tree abuse Address any disease issues Evaluate cultural practices 9

Why Should We Prune?

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Consider mature tree height Consider potential targets Correct Co-dominance and poor cultural practices 10

When is the best time to prune?

Time to prune.

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Depends on location

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Is cold weather imminent?

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Do you want flowers/seed/fruit?

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Is there a hazard present?

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How to prune?

Prune for good structure.

Pruning uses intentional cuts in a prescribed fashion.

Pruning should never be random!

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Less is more with pruning and pruning trees and shrubs while young is the best value for your time and money.

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Good structure can often mean survival during windstorms.

Prune for good structure • Co-dominant leaders and bark inclusions are the cause

of most tree failures.

• Subordination of codominant leaders is the cure.

• A single dominant leader is the goal of good structural pruning…

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Types of pruning cuts

How do we prune for structure?

Reduction (Drop Crotch) -

used to reduce the size or subordinate a co-dominant situation Removal (Thinning) – to

shorten lateral limbs, clearance Presentation title

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Reduction Cut (Aka drop crotch) •

Used to reduce the size or height

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Cut back to a limb at least 1/3 the diameter of parent limb.

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To subordinate a co-dominant situation, when two limbs compete for leader 16

Pruning for good structure

Removal Cut (aka Thinning cut) • To shorten lateral limbs and direct growth • Clearance Presentation title

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Respect the Branch Collar The branch collar is made of

Make proper cuts!

specialized wood that compartmentalizes the wound,

resisting decay. Trees never really heal. Never make flush cuts!

The Three Point Cut should always be used with limbs larger than 1 inch in diameter - protects the branch collar, prevents trunk damage.

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Avoid Trunk and Limb Tears: Use the 3-Step Cut

When removing a branch larger than 1” in diameter, make three cuts to avoid stripping bark from the collar and trunk causing serious and irreparable damage.

Plant more densely, in groups

Natural structure in groups.

Planting in groups of at least 3-5 will give trees the competition they need to stretch more towards the sun and develop a straighter trunk with less co-dominance. Think about the forest…Trees hold each other up and allow the air to move over them.

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Observe, then Prune for structure.

Many native trees are naturally co-dominant What does this mean for pruning?

We need to train trees while young to create a single leader, by subordinating the co-dominant parts. This should be done in the

nursery, at planting and during the first years of establishment.

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Plant smaller native trees.

Florida native trees and shrubs usually outperform exotics Smaller trees and large shrubs are easy to design with, and cause less problems to driveways, sidewalks and pavers.

Their smaller stature means little to no pruning once good structure has been developed.

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As with most skills, there is a right way and a wrong way to do it.

ANSI A-300 Ed Gilman, UF ISA (International Society of Arboriculture)

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Fiddlewood

Citharexylum spinosum Pruning objectives • Develop a leader, tends to be very codominant, use reduction cuts • Provide nearby competition to direct growth upwards • Flowers on new wood, so don’t prune in the spring, when flowers are developing. Male and Female plants. Need both for fruit.

• It’s extremely fragrant.

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Redberry Stopper

Eugenia confusa Pruning objectives • Develop a leader, can be multitrunked • Doesn’t require much pruning, some directional pruning only • Columnar growth habit, excellent for borders, informal hedges; very delicate habit and slower growing than the other Stoppers 26

Spanish Stopper

Eugenia foetida

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Pruning objectives • Develop a leader, tends to be very codominant, can be multi-trunked • Doesn’t require much pruning, mostly directional • Columnar growth habit, excellent for borders, informal hedges; can be hedged, but best if left natural and hand pruned. Best hedge of all the Stoppers. Tolerates dry, poor soil and full sun well. Little irrigation needed once established.

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Florida Privet

Forestiera segregata Pruning objectives • Develop a leader, tends to be very codominant, can be multitrunked • Can be very rangy and unruly; needs strong structural pruning when young and yearly maintenance to maintain structure • Spreading growth habit, excellent for borders, informal hedges.

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Simpson’s Stopper

Myrcianthes fragrans

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Pruning objectives • Develop a leader, can be multi-trunked • Easy to shape and has an even growth pattern • Columnar growth habit, excellent for borders, informal hedges, but can also provide substantial shade, especially in groups.

• Excellent for attracting wildlife and very fragrant flowers and showy red fruit 29

Wild Lime

Zanthoxylum fagara Pruning objectives • Develop a leader as soon as possible • Difficult to shape and has an un-even growth pattern • Spreading habit, requires regular pruning to keep in bounds.

• Useful to attract the Giant Swallowtails.

But has dangerous recurved thorns.

Good for security near windows – Biscayne Prickly Ash a better choice.

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Florida Silver Palm–

Cocothrinax argentata

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Pruning objectives

• Slow growing and requires almost no pruning • Great accent plant

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Florida Thatch Palm Thrinax radiata Pruning objectives

• Slow growing and requires almost no pruning • Great accent plant

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Chrysobalanus icaco ‘Horizontal’ Horizontal Cocoplum Pruning objectives

• Naturally low growing • Can be used as a hedge • Prune the uprights when they form • Hand pruning is best, no hedge trimmers 33

Lantana involucrata Button Sage Pruning objectives • Decide on form needed • Can be managed as a multi-trunked small tree or as a large shrub • Can be used as a hedge, no hedge trimmers • Can be sprawling, so strong structural pruning is needed when young and to maintain Presentation title

• Best form in full sun

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Psychotria ligustrifolia Bahama Coffee Pruning objectives • Can be used as a hedge, no hedge trimmer • Best form in shade to part shade • Happiest in moist, or well irrigated conditions • Attracts pollinators and birds • Good as understory/ground cover around canopy trees 35

Psychotria nervosa ‘Little Psycho’ Pruning objectives • Can be used as a low hedge, ground cover - no hedge trimmers • Best form in shade to part shade • Happiest in moist, or well irrigated conditions • Attracts pollinators and birds • Good as ground cover around canopy trees Presentation title

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Randia aculeata Inkberry, White Indigo Berry Pruning objectives

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• Needs little pruning, slow growing • Attracts pollinators and birds • Will re-seed • Good as understory/ground cover around canopy trees • Very fragrant flowers, shiny leaves

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Schaefferia frutescens Florida Boxwood Pruning objectives • Needs little pruning, dense, slow growing • Attracts pollinators and birds • Will re-seed • Good as screen, informal hedge • Diecious, bright red berries on female plants • Tolerates dry soil and full sun

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Privet Senna Senna ligustrina Pruning objectives • Can be used as a hedge, no hedge trimmers • Best in full sun, tolerates dry soil • Attracts pollinators; host for Sulphur butterflies • Will re-seed • Good as screen, informal hedge

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Bahama Cassia Senna mexicana var. chapmanii Pruning objectives • Can be used as a low hedge, no hedge trimmers • Best in full sun • Attracts pollinators; host for Sulphur butterflies.

• Will re-seed, not long lived • Good as screen, informal hedge, as ground cover around palms Presentation title

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Canella winterana Cinnamon Bark Pruning objectives

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• Forms a round head, good for a specimen shade tree in a small yard, swale, near driveways, sidewalks, under powerlines, privacy screen • Dense canopy benefits from good structural pruning while young to create a single leader.

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Krugiodendron ferreum Ironwood Pruning objectives

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• Forms a round head, good for a specimen shade tree in a small yard, swale, near sidewalks, driveways, privacy screen • Dense canopy benefits from good structural pruning while young to create a single leader or can be multi-trunked

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Vachellia choriophylla Cinnecord Pruning objectives

• A free spirit; needs corrective pruning early and often!

• Can be developed as a multitrunked tree • Shiny leaves and showy flowers makes it worthwhile 44

You Can Change the World… one tree at a time.

Know Them • Spend time studying them using good books written specifically for Florida • Increase your planting palette!

• Get out into the natural areas to study their forms in the wild Presentation title

Prune Them

ChooseThem!

• Plant them in your own • Study proper tree yards and incorporate them pruning techniques more densely, in natural groupings.

• Practice the art of • Strive for more diversity pruning • Try to influence HOAs, City • Respect their natural Commissioners, friends and relatives. form • Their beauty will be evident to all

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Donna Corbelli Castro How to Grow a Forest - My 25 Year Experiment - UF/IFAS Extension Broward County

Thank you

(ufl.edu)

Donna.castro@ufl.edu

Resources Instructional videos - Edward F. Gilman - UF/IFAS (ufl.edu)

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UF/IFAS is an Equal Opportunity Institution

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