Root Ball Shaving Improves Root Systems on Seven Tree Species in Containers

et al. 2013

AUF

Self Cite

Some trees uproot in storms apparently due to root deflections that occur during nursery production. Root deflection in a nursery container may lead to poor anchorage because of insufficient root growth into the landscape soil, and container volume/tree size at planting may influence root deflection. This study was designed to evaluate establishment, root growth, and anchorage six years after planting Acer rubrum L. trees of four different sizes from four corresponding container volumes and maintaining them with two irrigation regimes. Impact of mulch on establishment and root growth was also evaluated. Trees from the largest containers grew slowest in the first three years due primarily to water stress. Trunk tilt during winching tests increased due to greater root deflection, less mass of the root-soil plate, and reduced root growth into the landscape soil with increasing container volume and tree size. In contrast to the poorly anchored larger trees that had most of their large roots retained in the original planted root ball volume, the largest roots on trees from smaller containers grew freely into landscape soil. This resulted in stable trees with many stiff, straight roots pushing down against mineral landscape soil outside the root ball during winching. Trees planted from smaller containers appear to anchor sooner than trees from larger containers and would be more stable in a storm.

Section: Anchoragementioning

confidence: 99%

Impact of Tree Size and Container Volume at Planting, Mulch, and Irrigation on Acer rubrum L. Growth and Anchorage

Gilman¹,

Miesbauer²,

et al. 2013

AUF

Self Cite

“…One recent study showed that light cutting of circling roots on shrubs enhanced the amount of roots growing into substrate of the slightly larger container (Blanusa et al 2007). Slicing (Quercus virginiana Mill., Gilman et al 2009) or shaving (Acer rubrum, Gilman et al 2010b) the #3 container periphery when shifting into a #15 container improved root system quality by removing roots that grew down, around, and up the container wall.…”

mentioning

confidence: 99%

“…Krasowski and Owens (2000) found that, despite a smaller root ball at planting, root systems of mechanically pruned Picea glauca (Moench) Voss seedlings produced greater root growth in field soil than control or chemically root pruned treatments. Removing all roots by shaving the periphery of several tree taxa has shown to be very effective at almost eliminating deflected roots within the root ball (Gilman et al 2010b;Gilman et al 2015), but its impact on roots and growth after planting into soil remains untested.…”

mentioning

confidence: 99%

Effect of Container Type and Root Pruning on Growth and Anchorage After Planting Acer rubrum L. into Landscape Soil

Gilman¹,

Paz²,

2016

AUF

Self Cite

Acer rubrum L. ‘Florida Flame’ were grown in #3 containers of eight types, then shifted to #15 containers, then finally into #45 containers. Half the trees were root pruned by removing periphery 3 cm of root ball at each shift to larger containers. In addition to and simultaneous with being shifted into successively larger containers, some trees from each container size were planted directly into soil. Type of container and root pruning had no impact on trunk diameter, tree height, or root cross-sectional area on trees planted into soil from any container size. Type of container influenced architecture of planted root systems evaluated when all trees were five-years-old with limited impact on anchorage. Container type only impacted anchorage of trees planted from #45 containers, and impact was small. In contrast, shaving root balls during production substantially reduced imprint left by all containers evaluated when trees were five-years-old. Shaving during production also improved anchorage by 20%–25% compared to not root pruning. More roots grew on north than the south side of tree in the nursery and landscape. Bending stress increased with trunk angle and its square while winching trunks to five degrees tilt.

“…Removing defects by pruning roots when trees of at least nine taxa were shifted to the next larger size dramatically reduced number of trees grading as culls (Anonymous 1998) in nursery containers (Harris et al 1971a;Harris et al 1971b;Gilman et al 2009;Gilman et al 2010c). Growing in certain container types can also improve quality by reducing root deflection (Gilman et al 2010a;Gilman and Paz 2014).…”

mentioning

confidence: 99%

Nursery Planting Depth, Mulch Application, and Root Pruning at Landscape Planting Affect Tree Health and Anchorage

Gilman¹,

Paz²,

2015

AUF

Self Cite

Influence of root collar depth in a nursery root ball and potential root remediation when planting into the landscape are subject of increasing research. Mulch placement on root ball surface at planting has also been called into question recently. Trees planted deeply in nursery containers required ≥41% more time to remove substrate and roots growing over the root collar at planting than trees planted shallowly. Circling roots on trees planted from 170 L containers persisted for five growing seasons after planting into the landscape unless remediated by pruning at planting. Root remediation improved Ulmus and Acer root systems by dramatically reducing percent trunk circled with roots without influencing post-planting xylem potential, crown growth, or anchorage during the first five years after landscape planting. Mulch placed on the root ball surface caused more re-growth of circling roots on Acer—but not Ulmus—following root remediation. Bending stress to tilt trunks was most correlated with cross-sectional area of leeward and straight roots on Ulmus or windward and straight roots on Acer. The initial increase with time in bending stress required to tilt trunks after planting followed by a drop in bending stress suggests that trees planted from nursery containers could be more susceptible to uprooting in a wind storm as they became established beyond three or four years.