Your Small Kitchen Garden

I’m on a mission to plant a pear tree this fall in my small kitchen garden. In the past week, I’ve visited or contacted garden stores and nurseries within a half hour drive of where I live in central Pennsylvania—hardiness zone 5b. I’m ready now to concede that the local culture simply doesn’t believe in fall planting of perennials. That’s too bad for two reasons:

1. Planting in the fall has many advantages (read about them here)
2. I’m going to have to mail order my pear tree

A young fruit tree has a small section of root stock, grafted with a scion having several leaf buds and a terminal bud. Any of the leaf buds could develop into a branch, but if the terminal bud survives, in two or three years you can prune off the lower branches and promote branching higher up the tree’s turnk.

What I’d Look for at a Nursery

As I explained in my last post (click here to read it): Were I there to choose the tree in person, it would have a straight trunk running vertically up to a healthy leader—with, perhaps, a bump where the leader was grafted onto root stock. I would not buy a young tree whose main trunk made an abrupt change in direction, or had one dominant branch that was obviously thicker and reached higher than the main leader. I’d also be cautious of the distribution of branches.

Sometimes, it seems nursery operators prize low branches. Young trees often come with branches starting within a foot of the ground which is not a problem unless the tree’s main trunk makes an awkward diversion from vertical. When a tree has a vertical leader, within a few seasons, you can prune away the very low branches, and encourage growth on the higher ones.

However, when a young tree’s leader is at the end of a horizontal branch nearly as thick as the main trunk, it may take many years of aggressive pruning to train a new vertical leader that’s even vaguely in line with the trunk. If you’re growing a very small tree, then low branches make sense. But I want to be able to duck under my tree’s branches, so it won’t do to buy one that a nursery assembled with one or more main branches three feet off the ground.

It’s about Assembly at the Nursery

When you’re shopping for fruit trees, chances are you’re looking at chimeras. A chimera is an organism assembled from parts of several organisms. Especially in the cases of dwarf fruit trees, but often with larger trees as well, a nursery worker, through a craft called grafting, has combined two or more types of trees to make a single tree. The worker cuts a scion (a thin branch with several leaf buds and a leader at its tip), from a standard variety of fruit tree—say, a Bartlett pear. The worker also roots a variety of pear tree that has specific desirable characteristics, but that may produce unappealing fruit. The worker preserves the roots and cuts off most of the above-ground leader, replacing it with the Bartlett pear scion.

Over the course of a few months, the select root stock melds with the scion, and new wood and bark grow together to make a viable tree. The nursery worker makes sure no leaf buds survive on the root stock, so the only viable growth above ground is the good-eating variety of fruit.

Why the Grafting?

In grafting, the nursery worker is creating a tree with the best possible combination of features. Often, a desirable fruit’s roots are vulnerable to diseases, but the rest of the plant is hardy. It makes sense, then, to graft the desirable fruit onto a different root that won’t succumb to disease.

To make dwarf fruit trees, a nursery worker selects a “dwarfing root stock,” and grafts a desirable fruit onto it. The dwarfing stock simply passes water and nutrients to the rest of the plant more slowly than the plant would like… acting, in effect, like a bonsai tree master who cuts roots off of plants so they’ll grow up small though proportioned just like normally-grown trees.

Grafting can result in trees with undesirable shapes—especially when the nursery grafts two or more scions onto a single root stock (this is advantageous for fruits that require cross-pollination and is also necessary if you want two or more varieties of fruit from a single plant). Only one scion can be the tree’s leader… others must be branches—and when you graft a branch onto a three-foot tree, you have a tree that wants to be in your way when you do yard work.

What’s my Next Step?

I want to order my new pear tree soon so I can add it to my small kitchen garden in October. I’ll browse on-line nurseries, make a list, and share it with you in an upcoming post. When I select a nursery, I’ll explain why. I’ll also order a tree and explain my thinking about it.

Technorati Tags: fruit, fruit trees, grafting, pears, plant fruit

With my last post, Your Small Kitchen Garden started a mission to plant a pear tree this fall. Yesterday, when I made a grocery run, I stopped at a gardening store and was able to establish that Lewisburg, PA subscribes to the culture of “plant perennials in the spring;” there will be no pear trees—or any other fruit trees available until March.

This flies in the face of my philosophy (shared by many gardeners): planting in autumn has distinct advantages. The folks at the garden store were very helpful, offering up the name and location of the nursery from which they purchase trees, but by the time I drive there and back, I’ll have spent at least $25 for gasoline.

So, today I have no tree to plant, but I’m making phone calls to local garden stores and nurseries. Why all this hassle rather than click over to an on-line nursery?

Buy Fruit Trees Locally

I choose to buy locally whenever I can for the age-old reason: it supports the local business-owners. In small-town anywhere, local businesses need the support. But when it comes to planting fruit trees, I want as much control over my selection as possible.

When I order a plant on-line, I trust the seller will package up something healthy that is likely to survive if I treat it well. What I can’t be sure of is whether I’m going to like the shape of the tree they send.

This peach tree came from the nursery with a vertical trunk and a near-horizontal extension. The entire crown was (and still is) at the end of the horizontal extension. It’ll be four or five more seasons of pruning to correct the idiotic shape.

Shape Matters

The shape of a tree matters to me when I’m working around it. For example, when I’m mowing the lawn, I don’t want to bend over to mow closely to a tree. I also don’t want tree branches so low that the only way to mow under them is to stand away from the tree, and repeatedly shove the mower under, pull it back, and shove it under.

When a fruit tree has shoulder-level branches in the spring, those same branches are likely to hang down to knee- or ankle-level when laden with fruit. Mowing around them then can damage the fruit, knock fruit off the tree, and even break the already-stressed branches.

So, my ideal tree shape is a little odd: a branch-free trunk up to about five-and-a-half feet, and then a kind of flat disk of branches radiating around the trunk. In other words, I’d like to have mushroom-shaped fruit trees (I still have to duck under the branches, but I don’t have to bend low).

Truly Dwarf Trees

Were I planting a particularly small dwarf-variety of tree, I’d put far less emphasis on the tree’s shape. I would simply maintain a large circle of mulch around a tree whose crown diameter was six to ten feet. Then the first branch could start six inches up the tree’s trunk and I’d be happy.

But, I’m not planting a dwarf pear tree if I can avoid it. So, I want a tree I can prune into a shape that makes me happy. Were I there to choose the tree in person, it would have a straight trunk running vertically up to a healthy leader—with, perhaps, a bump where the leader was grafted onto root stock. If I end up buying through mail-order there’s no guarantee I’ll get a tree shaped like this.

Grafted? Root Stock? What?

Details about how your fruit tree is assembled are only slightly important to your success in growing it. But, it never hurts to understand what the store owners are telling you when they throw industry jargon your way. So, in my next post I’ll explain how the nursery operators assemble fruit trees, and how that can result in odd shapes, dwarfs, unwanted growth, and unfortunate tree failure.

Technorati Tags: fruit, fruit trees, grafting, pears, plant fruit