Renovation and Ecological Management of Neglected Apple Orchards in Southeast Michigan

PROJECT BACKGROUND

The site consists of approximately 3.5 acres of old apple trees mixed with mid succession shrubs and herbs. The land had previously been grazed by horses and was never managed as an orchard. The existing trees consist of a diversity of unnamed, seedling varieties presumably planted by wildlife. As of yet, no commercial yield has been derived from this system; the site has been used primarily for research and small-scale home fruit production.

  

Prior to receiving grant funds, orchard renovation was underway and ecological orcharding practices had been employed since 2011. Renovation pruning and soil improvement activities including the integration of compost and woodchips were underway at this point in time.

 

PROJECT DESCRIPTION

 

OVERARCHING GOAL: Establish a baseline set of regionally adapted practices for the renovation and ecological management of neglected apple orchard in the North Central Region

 

Objectives:

• Determine most efficient strategy (time/technique) for renovating the structure of neglected and feral apple trees.
• Determine most effective strategy (time/technique) for top-working new varieties onto abandoned trees
• Explore techniques for boosting tree health with biological spray applications
• Explore techniques for boosting soil health with biological spray applications and increased organic matter

 

PRODUCTION GOALS + ORCHARD A/A = RENOVATION APPROACH &

PRUNING REGIMES

 

PROCESS

Define Production Goals

Before any renovation work is carried out it is useful to know what the primary production goals are. This will inform pruning regimes and the overall renovation approach. An example would be to produce apples for cider production, or to produce apples for market sales, u-pick, etc. Our particular scenario happens to be focused on producing cider apples. Apples used for the production of hard cider are generally collected as drops rather than handpicked off the tree— thus the correlation between canopy height and harvesting efficiency is insignificant. Where in a u-pick orchard, for instance, canopy size may be a primary factor in harvesting efficiency.

 

Orchard Analysis & Assessment (A/A)

The early phases of the project were focused on analysis and assessment. Given that we set out to create guidelines and best practices for renovating neglected and feral orchards— the first step is to evaluate the condition of what you’re working with. Analysis was focused on looking sheerly at the state of the trees; assessment began to look at the implications and appropriate steps forward. We spent the 2012 and 2013 growing seasons evaluating the genetics, health and productivity, and structure of the existing trees. The following bullet points outline each one of the major A/A topics.

 

Genetics

Analysis Questions:

• What is the genetic resource base?
• Are the trees grafted, if so what cultivar(s)?

  • Are there visible signs of graft unions?
  • What rootstock(s) are the trees growing on?

• Are the trees wild seedlings?

 

Assessment Questions:

• Does the existing genetic resource base offer value pertinent to your production goals?

  • If the trees are grafted cultivars, then are they the cultivars you want to grow?
  • If the trees are grafted on clonal rootstock, then does the rootstock possess qualities you want to propagate? i.e. dwarfing, fire blight resistance, etc.
  • If the trees are unnamed seedlings, then are they worthy of being grown for their fruit? Are they worthy as understock for introducing new cultivars?

 

Tree Health & Productivity

Analysis Questions:

• Do the trees show signs of stress or disease? i.e. apple scab, cedar apple rust, fireblight/ non pathogenic stress factors, i.e. nutrient deficiency, drought, etc.
• Do the trees currently support a diverse and healthy arboreal food web?
• Do the trees have a high percentage of dead wood?
• Are the trees currently producing? If so, are the yields high, low, or moderate?

 

Assessment Questions:

• Does existing tree health pose any major limitations to your project?

  • Do diseased trees need to be removed altogether?
  • Can diseased wood be eliminated with pruning?

 

Tree Structure

Analysis Questions:

• Have the existing trees ever been pruned?
• Are there a high percentage of crossing branches, shaded wood, and shoots growing towards the interior of the tree?
• Do the trees have a lot of new growth (1-2 yr old wood)?
• Are there watersprouts visible on the trees?
• Do the existing trees vary in age and degree of neglect?
• What is the average tree height?

 

Assessment Questions:

• What percentage of the trees requires high, low, or moderate impact pruning?
• Do canopies need to be ‘lowered’ to make fruit harvesting and overall management easier?

 

Renovation Approaches & Pruning Regimes

After Analysis and Assessment we determined that two distinct classes of trees exist within our orchard— original variety trees, or trees that we wish to maintain as the existing variety, and host trees, or trees that we wish to graft over to new varieties. The pruning regime differed for host trees and original variety trees—

 

Renovation Approaches

Renovation Pruning of Original Variety Trees

The shape of each individual tree varies greatly in a neglected orchard—some trees have multiple trunks while others have single trunks with low branching and everything in between. The pruning for each tree becomes rather unique but follows some basic guidelines. Project goals will also influence the pathway to renovation particularly regarding final tree height.

• Remove all dead/diseased wood immediately
• Identify desirable tree height and top to that level
• Thin canopy to increase overall air/light infiltration
• Identify primary scaffolds, 4-8
• Carry out renovation pruning over 2-4 seasons

 

NOTE on final tree height: depending on the end production goal the desired canopy size will vary; e.g. for a cider orchard, standard trees with 25’+ canopies allows for drops to be harvested. Where a dessert apple orchard may require hand harvesting and therefore lowered canopies.

 

Renovation Pruning of Host Trees

Renovating host trees is a more extreme pruning process, as the end goal is to have a tree that is entirely free of branches of the original genetics. Although similar to renovation pruning of original variety trees, this approach is typically faster and creates a more abrupt change.

• Remove all dead/diseased wood immediately
• Select 3-5 main scaffolds to develop into ‘host limbs’
• Head back 1-2 scaffolds each season for 2-4 seasons to create host limbs

 

NOTE on heading back scaffolds: consider pruning in a sequence that will not create breakage problems for grafted limbs down the road. E.g. head back uppermost limbs and graft those first, subsequently cuttings lower branches in following year.

 

Topworking Host Trees

• One or multiple cultivars
• Graft 2-3 host limbs (primary scaffolds) each season, maintain minimum of 1 ‘nurse limb’
• Techniques used: rind graft AKA bark graft, modified side bark graft*, cleft graft,  whip/tongue

 

Rind Grafting

• Timing: May-June
• Advantages: high take rate, 80-95% EASY
• Disadvantages: prone to breakage; graft upward side

 

Cleft Grafting

• Timing: Early April-May
• Advantages: early season technique, doesn’t require bark slipping
• Disadvantages: wood prone to splitting, medium difficulty on 4”+ diameter wood

 

Whip And Tongue

• Timing: Late April-June
• Advantages: forms strong union— same diameter understock, easy to train; high take rate; secondary option to failed bark grafts
• Disadvantages: challenging technique, difficult to position in tree

 

 

Ecological Management Strategies

• Scything/mowing schedule
• Utilize rotational chop-n-drop technique
• Introduce OM— woodchips, hay, etc.
• Overseed soil-building seed mix (clover, daikon, chicory, etc.)

 

Arboreal Food Web & Tree Health:

• Spray aerated compost tea
• 50 gallon brewer, applied w/ backpack sprayers
• Leaf tests analyzed by Soil Food Web, Corvallis OR

 

Next Steps

• Continue evaluating graft growth rates, pruning techniques, productivity, etc.
• Explore pruning/training techniques for grafts
• Maintain original varietal trees with routine pruning
• Propagate successful varieties
• Assess T-budding and chip budding as viable top working methods
• Renovate more orchards and find more projects

 

PEOPLE

Trevor Newman and Mark Angelini were the two project managers and primary individuals involved with carrying out the project. Independent arborist, Justin Pawloski, was employed for specialty tree work involving clearing some of the surrounding canopy trees. Plow Guy, LLC was employed to brush hog the understory of the orchard. Ongoing support and networking was provided from MNGA and NAFEX.

 

RESULTS

We achieved four primary results: increased health, structure, and vigor of the neglected trees through renovative pruning; increased genetic diversity through the introduction of named varieties via top-working; increased biological leaf coverage via foliar spraying; and increased biomass accumulation and cycling in the understory via brush hogging, scything, mowing, and woodchip mulching. As fifth result, which we wish to acknowledge but have not quantified, is the economic benefit of renovating and ecologically managing neglected apple orchards.

 

The first of these results was measured from a purely empirical standpoint: the trees responded with bursts of new growth, more regular cropping, and overall improved vitality, vigor, and yield following renovative pruning; we have successfully introduced 50 varieties via topworking; On our test samples, biological leaf surface coverage increased by an average of 8%; While our soil biology tests show little increase in overall fungal activity, which was what we have worked to improve, we have begun a solid understory management regime which has cycled more biomass into the soil since we began, as well as made the orchard easier to access, maintain, and harvest from. As far as economic benefits, we see much anecdotal evidence of this being a key result in our work. While we are not yet at a point in the project to assess the economic value of the yields of the various apple varieties, we can thus far assess that the ecological approach yields cider-quality apples at the expenditure of little labor and energy. It produces a living germplasm resource for site-selected genetics for fruit and rootstock, as well as a bank for introduced genetic diversity to be drawn from in the form of scionwood to be used to expand plantings going into the future.

 

The first three results were as we expected. And only part of the last result was not as we expected—the fact that fungal activity had not increased. This is unexpected mainly because we have spent the last two years putting down more fungal food biomass than this orchard has perhaps ever seen. We suspect this is because of the fact that the area was grazed so regularly for 20 plus years. However, with all of this taken into account, we are unsure if we would do anything drastically different next time—our trees are thriving and producing healthfully. To us, this indicates that a multi-pronged approach for renovation and ecological management is paramount and that using the tools and techniques most readily available will produce favorable results.

 

DISCUSSION 

We learned the most about the various subtleties of intervening in a neglected orchard, primarily relating to the timing of intervention. We found that major renovation work regarding the structure of the trees is best done from December to February. We found that top-working of limbs must be done in one fell-swoop—leaving the main host limbs untouched until the day of planting e.g. in early stages we headed-back the host limbs during the structural pruning of winter and found that by the time for grafting came, these limbs were senescing and many died as a result. Top-working has been most successful for us from May through as late as early July when the bark is slipping readily and average daily temperatures are above 50 degrees Fahrenheit. This has affected our farm operation by giving us clear guidelines as to when each phase of work must be conducted to produce the best results for the tree and graft.

 

A project such as ours has many advantages as well as its share of disadvantages. The primary advantages as we see them are:

• The opportunity to utilize marginal orchards that have been left neglected and overgrown and thus the various economic, ecological, and social benefits this holds.
• The quick return on investment from graft to yield on mature, overgrown apple trees (we are seeing a 3 year cycle from graft to production for top-worked trees).
• The preservation of site-adapted genetics via existing rootstocks, as well as the promise of novel genetics in the form of unnamed seedling apple varieties.
• The economic, ecological, and social benefits of managing an orchard ecologically.
• The nutritional advantages of producing apples under ecological management.

 

Some disadvantages we have found include:

• Working within the relative randomness or disorder of a neglected orchard and thus the various challenges this presents regarding access, tree spacing, and layout.
• The labor involved in performing the necessary structural re-habilitation of the trees as well as taming the understory in which the neglected orchard exists.

 

We would tell other farmers or ranchers that at the very least, the ecological management of an orchard for cider-quality fruit is here and now—that any apple orchard planting can be easily converted to an ecological management model and many costs could be spared in the process. In terms of whether or not we can recommend the renovation of a neglected orchard to achieve this, we would likely pose the questions presented under the Process section.

 

OUTREACH

During the grant cycle we have performed outreach in multiple outlets. Our first outreach was a field day hosted via the Oakland County Permaculture Meetup in the summer of 2013—this is a local group of 500+ members that meets monthly to network and share information regarding local food systems, homesteading, farming, gardening and all things related to sustainable land use. This meeting hosted 35+ members from the group whom learned about our grant project and the various renovation activities being conducted in the orchard. In 2014 the group returned again to the orchard to learn about the progress being made on the orchard renovation.

 

In 2013, 2014, and 2015 we shared our grant information with students in six 10-day Permaculture Design Course curriculums. Over these 6 courses, our grant work and findings was presented to over 200 individuals actively working in sustainable agriculture and land use.

 

In 2013 our grant work was presented at the Michigan Small Farms Conference in Traverse City, MI to around 300 farmers and homesteaders from around the state of Michigan in two presentations led by Trevor and Mark.

 

This October our grant report finding will be presented to 35 students in a Farmscale Permaculture Course in Iowa held at Versaland farm, one of the Midwest’s leading tree-based agroforestry farms.

 

We plan to further report our grant work to local media via press release to local news outlets as well as compiling a more formal report booklet to be permanently hosted to our website and shared with our network of over 2,500 email, facebook, and local followers.

 

 

• Grafted Cultivar List
• Leaf Sample 2 2013
• Soil Test 2013
• Leaf Sample 1 2015
• Leaf Sample 2 2015
• Renovation & Ecological Management of Neglected Apple Orchards in SE Michigan Full Presentation
• Harvard Compost Tea Brewer
• Soil Test 2015
• Leaf Sample 1 2013