Thursday, May 23, 2013
In a nod to Valentine’s Day today’s post is about grafting, the act of joining two plants together. Grafting is done in the spring before the leaf and flower buds start to grow and when sap is flowing so the bark is loose.
Here in Maine folks will be grafting in late March and early April. C.J. Walke, the Maine Organic Farmers and Gardeners Association’s Organic Orchardist clues The Root’s readers in on the basics of spring grafting.
How (and when) did you get interested in grafting?
In 2006, I started working for the Maine Organic Farmers and Gardeners Association (MOFGA) and attended a MOFGA grafting workshop that spring. I found it fascinating that you could basically cut a piece off a tree, tape it to another and it would grow. Of course, it’s a little more technical than that, but I was hooked.
Are you working on any specific grafting projects?
We graft new trees for the MOFGA grounds every spring. I also am annually top-working grafts on to old apple trees on my property in Swanville. And I am involved with College of the Atlantic and help with some of their orchard propagation. Some of the folks I prune for in the winter have asked about grafting for their gardens, but nothing’s confirmed.
What are your must-have tools for grafting? Preferred sources?
Hand pruners, grafting knife, wound sealer, grafting tape, scionwood, rootstock. You would need larger pruning tools for grafting on to older trees. The best source around here is Fedco – they have all the tools/supplies. MOFGA holds a scionwood exchange (March 24, 2013) where you can get scionwood for a simple swap.
What are compatible combinations of rootstock and scion you would recommend in Maine?
Typically you need to stay within the species you’re working with (i.e. apple to apple, pear to pear, plum to plum). Though peaches are often grafted on to plum rootstock. Pear can be grafted on to quince. Rootstocks have their zone ratings like other perennials, but most are hardy to Maine. It all depends on the size of the mature tree that you want to grow.
There are so many ways to graft, how does one know which kind to use – or maybe what is the most common type of grafting for a novice?
It depends on your situation. The most common is bench grafting using a whip and tongue graft, which is done in the early spring. That is how you would start a new variety on a rootstock and probably the easiest to start with for a novice. Bud grafting is also common, but that is done in mid-late summer and can be a little more difficult, but yields quicker results.
Rootstock (or stock) – The root, branch, or tree trunk into which a graft or bud is set. This provides the new plant’s root system. Walke's definition: Rootstock has roots on it, so just the young trees that you graft on to and plant in the ground. Stock can mean rootstock, but also the limb of an existing tree that you graft on to. So a rootstock provides the root system for the scion that is grafted, but when grafting on to an existing tree, that tree is already established and in the ground.
Scionwood (or scion) – Walke's definition: Scionwood or scion is the piece that is grafted on to the rootstock or limb of an established tree, and it is the previous season's growth or better to say that it is one-year old wood. Scionwood needs to be cut from the tree while it is dormant, so in winter, and stored properly until used for grafting.
Proper storage can be a couple different things, like triple bagging it in plastic bags or zip-loc bags, adding a small piece of damp, but not wet, paper towel to retain moisture, and storing in the back of the fridge. Some folks may store scionwood loose in a cooler and bury the cooler in the snow on the north side of a shed or barn. The goal is to keep the scionwood dormant (cold, but not frozen!!) and prevent it from drying out. So scionwood loose in the fridge will dry out and shrivel, becoming useless, hence the triple bagging. And putting it in the freezer, bagged or not, will also kill it.
Usually an orchardist will prune his/her fruit trees, then gather scionwood from the pruned branches. Most importantly, clear labeling of the varieties is essential because you cannot tell a Macintosh from a Black Oxford just by looking at the scionwood.
Types of Grafts
Bark Graft – When scionwood is inserted into the rootstock. Slip piece of scionwood into the bark at an angle between the bark and the cambium layer.
Inlay Graft – Same as bark graft, except a rectangular shaped piece of bark is cut out of the stub and the scion is cut to fit.
The above photo is an example of top-working on a plum Walke did last spring. This is using the inlay or bark graft, with four scions spaced evenly around the cut branch. Black stuff is Tree-Kote to keep the wounds from drying out, so they heal. The white tape helps to hold things firm until the grafts take. Walke cut the tape off a month or two later.
Whip or Tongue Graft – More difficult than bark or inlay grafting. Used when the scionwood and rootstock are about the same size.
The above photo is an example of a whip and tongue graft that is one year old. The rootstock is lower/browner color. The reddish part is the scionwood (the short stub with a black top) and the long reddish stick is the first year of growth off of the scion.
MOGFA’s 12th Annual Seed Swap Scion Exchange on Sunday, March 24 between 9:00 a.m. – 4:30 p.m. at the Common Ground Education Center in Unity.
Other sources for scionwood: Fedco, and local nurseries. In some cases from one’s own trees or a friend’s trees.
MOGFA is holding a series of workshops, covering theory and hands-on practice in organic fruit tree and orchard management. Designed for beginner to intermediate orchardists managing backyard plantings to larger orchards. April 20: Grafting Fruit Trees (bench grafting/top-working) $50 in Unity. July 27: Bud Grafting $30 in Thorndike.
Grafting Fruit Trees: Storey's Country Wisdom Bulletin - practical, hands-on instructions
Photos by C.J. Walke.Tweet
Sharon Kitchens is a neo-homesteader learning the ins and outs of country living by luck and pluck and a lot of expert advice. She writes about bees for The Huffington Post and stuff she loves on her personal blog, deliciousmusings.com.
When she is not writing, she enjoys edible gardening, reading books on food and/or thinking about food, hanging out by her beehives and patiently tracking down her chickens in the woods behind her old farmhouse.
In her blog, Sharon profiles farm families, reports on farm-based education and internships, conducts Q&A's with master beekeepers, offers tips on picking a CSA, and much more.