Renovation and Ecological Management of Neglected Apple Orchards in Southeast Michigan
The 2013 season was a year of identification, beginning renovative pruning, performing preliminary tests, acquiring major implements and materials, and observation. We worked on orchard analysis & assessment, pruning, and topworking from February through June. We sent in test samples in late May. We used the orchard and our grant related work to educate our community about orcharding and our project at large during early and mid spring. We built a 50 gallon compost tea brewer in July. We scythed multiple times throughout the growing season. And we tasted many of the seedling apples, evaluated our pruning and grafting success and failures, and tasted ciders from the orchard from September to December.
-Catalog & Identify ? of specimen trees
-Assess & carry out renovative pruning on specimen trees
-Topwork and multi-graft specimen trees
-Clear brush and scrub trees surrounding specimen trees
-Over-seed and diversify understory
-Design & build 50 gallon compost tea brewer
-Acquire backpack sprayer and scythes
-Send in leaf and soil samples for testing
-Scythe and manage understory
-Observe growth and pruning response
-Assess pruning and grafting strategies
PRUNING & GRAFTING
Strategies & Approaches
During the spring of 2013 a systematic ID system was established for ? of the orchard trees. In the winter of 2012-13 major renovation pruning was carried out on approximately ? of the total orchard trees; this was a continuation of pruning work initiated in the winter of 2011-12 aimed at gradually renovating a number of old and neglected trees over the course of 2-3 years. Scrub trees and shrubs (box elder, cherry, rose, honeysuckle) in the surrounding vicinity were removed to increase sun exposure to the orchard. Orchard prunings were reduced in size and left as rough woody mulch in the orchard understory.
Thus far we’ve discovered two distinct individuals which require unique management and renovation techniques— trees that are to be maintained as existing varietals and trees that are to be topworked over to new single or multi varietals. We’ve established the need for two different pruning strategies for each tree type— trees intended for topworking are thinned severely in their 2nd and 3rd seasons of renovation; ultimately 3-6 scaffolds are chosen and left in place as hosts limbs for new varieties. Compared to the latter, existing varietal trees are left more intact in terms of their original branch structure and overall canopy architecture.
As a continuation of the topworking done in 2011 and 2012, in April and May of 2013 several new cultivars were grafted onto host trees intended to be maintained as single or multi varietal trees. This was done in part to trial a wide diversity of apple cultivars and also to establish the most effective means of topworking old trees (see CHART #4). Two main grafting techniques were employed— rind grafting (see PHOTO #4) and cleft grafting (see PHOTO #7). Utilizing five different host trees numerous cultivars were introduced into the orchard during the spring of 2013 (see CHART #4). Thus far we’ve discovered many factors that influence the success of grafts. These include staking, host tree compatibility (influenced by many unknown factors), the type of graft used, and severity at which the tree was renovated. Two distinct strategies have surfaced for approaching topworking— one that uses large diameter wood (2″- 8″) as host limbs for grafting onto and another that uses watersprouts as host limbs. In time we hope to discover which method is the most appropriate for certain situations.
On April 4th, 2013 a renovation pruning demonstration was offered to the Oakland County Permaculture Meetup Group. This pruning demo was followed up with a topworking demonstration on May 13th, 2013. Approximately 20-30 local farmers and gardeners attended each demonstration (see PHOTO #1). Pruning and grafting demos served as a way to share our project with the local community and raise awareness about the potential for apple tree renovation in southeast MI. Summer pruning was done during 2013 to eliminate water sprouts on specimen trees and encourage good air and light infiltration to grafts (see PHOTO #2). Watersprouts were removed as early as possible while still green and tender. Grafts were monitored throughout the growing season.
Leaf & Soil Samples:
Arboreal & Soil Food Web Evaluation
Leaf samples from trees A6 and A12 were sent to Earthfort Labs in July 2013. These initial samples were done to evaluate existing diversity of the arboreal food web prior to any treatments— these are the ‘before’ samples. Bacterial and fungal counts for the initial samples were deemed ‘inadequate coverage’ according to Earthfort Labs minimum percent coverage necessary for significant disease prevention (see CHART #1/2). A second set of leaf samples will be evaluated in 2014.
A soil sample was also collected and sent to Earthfort Labs in July 2013. Pre-treatment soil samples were evaluated and will be compared to soil tests performed after treatments in 2014. Initial tests showed existing soil conditions to be bacterial dominate and low in fungal activity (see CHART #3). Future treatments will aim to increase fungal dominance; further testing will determine which methods prove effective.
Compost Tea Brewer:
Set-up & Establishment
In the summer of 2013 we built a 50 gallon compost tea brewer. Tea applications will be sprayed during the spring, summer, and fall of 2014; this process will be documented and ultimately tested for its effectiveness at increasing arboreal foodweb diversity.
Scything & Understory Management:
Strategies & Approaches
The orchard understory was scythed multiple times through the 2013 growing season (see PHOTO #5). Biomass was left as mulch. All orchard prunings were consolidated and used as rough mulch beneath trees. Woodchip mulch mounds were laid out haphazardly beneath each tree (see PHOTO #6). Additionally, spent pomace from cider making was returned to the orchard understory (see PHOTO #9). These mulching practices are all aimed at increasing soil organic matter and ultimately soil health. Another goal is to increase the soil’s carbon content and ultimately transistion to a more fungally dominant soil type. Future testing will determine the effectiveness of these strategies.
- PHOTO #2: Summer pruning watersprouts/ evaluating grafts
- PHOTO #4: Topworking a renovated apple tree using rind grafting
- PHOTO #6: Ramial woodchips used as haphazard rough mulch
- CHART #1: Leaf test results from tree #A6
- PHOTO #3: Showing growth from a broken rind graft
- CHART #2: Leaf test results from tree #A12
- CHART #4: Orchard Renovation Log
- PHOTO #1: Cleft grafting demo for Oakland County Permaculture Meetup group
- PHOTO #5: Scything the orchard understory during midsummer
- PHOTO #7: Healthy union on a double cleft graft
- PHOTO #8: Fall harvest from seedling trees
- PHOTO #9: After pressing apple juice the spent pomace is used as mulch in the orchard
- CHART #3: Soil test results
Impacts and Contributions/Outcomes
Adding to what has been previously mentioned, we are finding that our renovation activities in the orchard appear to be having a positive impact on the orchard as an ecosystem, as well as the trees themselves.
We’ve found that close monitoring of grafts is helpful in ensuring their success. Some varieties when topworked grow very fast in the first several months, putting on more weight than the yet-healed union can support, thus breaking off. With careful topping and management this is avoided. Conversley, some topworking, in our observation, can be slow to take and appear as if stunted. In these cases we have made sure they are getting enough light and that the union is healthy. This may also come down to vagries in rootstock/variety compatibility.
We are finding that a bulk of the labor in renovation is taken up by clearing scrub and brush from the understory, as well as thinning out competing wild trees such as box elder and cherry. Pruning is the next most labor intensive process, because the overgrown neglected trees have excessive amounts of branching which takes a considerable amount of work to address.
Scything and mulching the understory appears critical in ensuring a healthy balance of understory and canopy. Scything not only produces mulch, but incites root die-back, stimulating the understory plants to grow many times the biomass they would if left untended. Mulching locks in soil moisture and adds much needed food for the fungal network.
- Renovated existing varietal trees—seedling specimen that we are maintaining, because of good flavor, etc.—are producing healthy, sometimes substantial, yields the season following initial pruning.
9260 Autumnglo Rd.
Clarkston, MI 48348
Office Phone: 2486131091