A reader of Ministry Of The Fence recently asked me about what to add to the soil for planting a new fruit tree. She posed the question in the comments section of the post entitled “Tea And Bananas: Saving Water, Feeding Plants“. Her question got me thinking. Planting fruit trees is a tricky business but can be so rewarding. As spring is springing (finally) and many a gardener’s fancy lightly turns to thoughts of agriculture, now’s a great time to do a little digging into those tips that aren’t so well known but can make all the difference.

Ripe apples dangling from a tree branch in Ontario.

8 not-so-obvious tips for planting fruit trees

1. Dig the hole before you’ve even bought the tree.

You need to know exactly what you’re dealing with in terms of soil type, moisture retention, etc. There are four types of soil, generally speaking: clay, sandy, chalky and humus-rich. Each has its own relatively distinctive colouring and characteristics such as allowing great drainage (sandy) or poor drainage (chalky) or poor moisture retention (sandy). If you’re not sure what you have, take a picture of the hole and discuss the situation with an expert at your local garden nursery. Once you’ve assessed what you’ve got, you can make amendments as needed (see Tip #5).

Knowing what type of soil you have will also help you make the best decision in terms of type and variety of fruit tree. For instance, plums are very undemanding. They’ll thrive in just about any soil except sandy, dry soil. Pears are not happy in lime-rich or dry soils but can tolerate heavier, poor-draining soil.

If you’re an old hand at gardening and know your soil like the back of your hand, so to speak, consider digging that big hole early in any case. As you’re probably already aware, you never know what you’ll find sometimes.

2. Make sure that hole is square.

What’s the point of putting a round root ball in a square hole? (This is not a rhetorical question.) For encouraging good root growth that splays out rather than growing in ever tighter circles, plant that round root ball in a large hole with straight sides. Roots that hit a round wall of undug dirt will tend to take the path of least resistance and follow the curved wall. But roots that fan out and hit a flat soil wall or an angular corner are more likely to push through into the un-dug soil.

3. Look over the fence before buying more than one tree.

If the tree you’ve chosen is self-fruitful you’re good to go. But if your tree is self-unfruitful, you’ll need a second tree to cross-pollinate. Ask about what kind of cultivar you’ll need but before buying a second tree, look around your neighbours’ yards. An apple tree can be pollinated with a crabapple tree, for instance, and if one is growing in your next door neighbour’s backyard, problem solved.

4. Shop for disease resistance, not a pretty name.

‘Disease resistant‘ may be one of the most unromantic phrases around but if you want to avoid tears and heartbreak later, ignore all the pretty photos on the tags at the nursery and don’t be smitten by a tree that promises the same fruit as your favourite grocery store purchase. Popular grocery store fruits can be a challenge to grow outside of commercial orchards. Instead, find the fruit tree variety that offers the best disease resistance available. You’ll usually find a better selection of these at a garden nursery specializing in fruit trees. Check out native or locally bred options while you’re at it. Canadian apple cultivars in particular are a great choice.

5. Be stingy with the fertilizer.

All fruit trees are heavy feeders and love a conventional smorgasbord of nitrogen, macro and micronutrients. There are plenty of commercially-sold fertilizers specifically formulated for fruit trees that contain all those things. The trick is to only apply a fertilizer (organic or chemical) to make up for what your soil is lacking and what your trees need.

Although nitrogen seems to be the magic bullet of fertilizer ingredients, go slow and stingy. By adding nitrogen fertilizer to the hole before planting the tree you can risk burning the roots. Oregon State University’s Extension Service has a good report on Fertilizing Fruit Trees and, interestingly, it states that it’s best to hold off using any nitrogen fertilizer for several months in the first growing season until your young trees’ root systems are established. Then, apply 5-10 pounds of aged manure, sprinkled around the tree’s drip line and carefully dig it in.

Once you’re ready to add nitrogen, stay stingy. Apply too much nitrogen and you’ll get more leaves than fruit. In the case of pear trees, too much nitrogen can also stimulate new shoots that are susceptible to fire blight.

6. But go to town with the Myke.

Myke is an all-natural supplement for trees and shrubs that, among other things, aids the whole transplanting process and can get your fruit tree off to a strong start. The organic part of the Myke – which you can get at most any larger garden centre – is mycorrhizae, a symbiotic fungus that helps your tree’s root tissue quickly and efficiently absorb water and mineral nutrients from the soil. Apply as per package instructions to the planting hole just before adding your tree.

I swear by this stuff.

7. Walk away from the sprinkler.

When the whole point of growing a fruit tree is to enjoy the fruit, you need to be diligent about keeping the tree disease-free for the best harvest. Water your tree from a clean water source (your tap) rather than a pond, for instance, which could have water-borne pathogens. Water with a hose at ground level as overhead irrigation (hello, sprinklers!) can also spread disease, splashing airborne pathogens and those from infected surfaces like leaves to your tree.

For those readers who are still awake and thought “Hey! Rain is an overhead irrigation!”, you get a gold star. Yes, rain can spread disease too unfortunately but by avoiding sprinklers you’re at least cutting down on the risk.

8. Don’t forget the green manure.

The best on-going organic nitrogen supplier for your trees, in my opinion, is clover – a natural nitrogen-fixing cover crop also known as green manure. The clover’s root system offers great soil conditioning and, once mowed down and dug into the soil, offers extra nitrogen for your trees. If you’re hard pressed to decide between red and white clover, red clover attracts more beneficial insects than white clover. But both clovers also make excellent weed suppressors. One word of caution, clover can be quite invasive so be prepared to have it pop up uninvited in your lawn and garden beds (which isn’t necessarily a bad thing).

Do you have any great not-so-obvious planting tips? I’d love to hear about them.