Pruning: What, when and how

One of the most important parts of maintaining a healthy garden or landscape is regular pruning. While it can feel counterintuitive to cut back plants we want to be as large and healthy as possible, it helps keep them healthy from disease as well as allowing the living portions to have more room and sunlight, provides easier access to pollinators and can help slow the spread of disease. It even encourages fruit trees to produce more plentifully!

Fruiting bushes

Bushes like blackberries and raspberries are generally known as “brambles”. With good care and tending, these can bring in fruit for you for the next 10-30 years. You may be sensing a theme by now, in how they’re divided for pruning purposes.

Floricanes:

Floricanes are bushes that bloom on their canes (shoots from the ground), with buds that were formed on last year’s old growth. If you cut the canes in the first year, you’ll be cutting back all of next year’s fruit. These should be pruned back after fruiting is finished, cutting back to the ground while leaving all canes that haven’t produced berries yet.

Primocanes

Primocanes, fall bearing or ever bearing varieties produce fruit both on the floricanes (2nd year growth) as well as the 1st year primocanes. If you’re growing this type of berry, it’s best to sacrifice next year’s early summer yield by pruning back after the last harvest in fall. This will produce fewer but larger and better tasting berries next year.

Trees

Shade Trees (non flowering)

There are two schools of thought when it comes to non-flowering shade and ornamental trees: pruning for strength, and pruning for form. We’ll be concentrating on pruning for form here, as shape and design is somewhat subjective and can easily fill an article on its own.

The ideal in this case is a stable, thriving tree. Healthy trees will still be aesthetically pleasing, but pruning is done to support the shape the tree wants to grow into, rather than selecting branches for shape and symmetry.

When pruning for strength, take care to remove any water sprouts and suckers as well as any branches that rub together and can create wounds in the bark. Prune to keep a stable center of gravity and correct any leaning the tree might be doing due to wind or access to sun.

Flowering Trees

While a good rule of thumb for most trees and shrubs is to prune in late winter or early spring, good practice is to determine this based on when your plant is blooming.

If your tree or shrub blooms before the end of june, prune old growth immediately after flowering. Flower buds will have developed during the previous season’s growth, so cutting branches down that haven’t had a chance to flower will result in, well, fewer flowers.

Other trees which flower after the end of june very likely grow on new growth, and should be pruned in the standard winter/early spring to allow buds to set during the growing season.

Fruit Trees

While garden experts will tell you that different fruits are pruned in unique ways, if you’re growing pomme or stone fruits (apples, cherries, peaches, pears, quince, etc) which make up most of what we grow outside the tropics, there’s a simple 3 step process.

1. • Clean up:

Remove all wood that is dead, damaged or diseased, as well as any watersprouts or suckers. With all these cuts, make sure to prune back flush to the larger limb your branch is growing from rather than leaving stubs.

1. • Thin:

Remove any branches that grow downward, towards the center of the tree or that cross paths with another branch. Look for places where multiple branches compete with each other, leaving 6-12 inches of air space around the larger branches. This will allow light and air into the canopy, boosting fruit production and lowering your risk of pests and diseases.

1. • Give it a haircut.

Prune back the outermost growth so that the branches are shorter and thicker as the grow, keeping them safe from bending and breaking under the weight of its own fruit. Cut back around 20% to 30% of last year’s growth, and cut partially down into each branch rather than down to the parent limb as we did in the last two steps.

Hedges and evergreens

Prune in late winter, when the plants are dormant and haven’t started producing any buds yet. When new buds are pruned off, that’s wasted energy that the plant could have put toward another purpose. Evergreens in particular are quite slow growing, so make sure to prune them as early in the season as possible so nothing is wasted.

Roses

Unlike hedges and evergreens, roses are actually stimulated by pruning, so care should be taken not to prune too late/early in the season to keep any tender new shoots from freezing.

Rejuvenate your roses with an annual springtime pruning. Clear out all branches narrower than a pencil, as well as any diseased or broken wood. Choose the 6-8 strongest canes to an overall height of 18” – 24” and enjoy bigger, healthier blooms.

Hydrangea bushes

Mophead, Lacecap and Oakleaf types

If you have blue or pink hydrangeas, or white blooms with huge oakleaf shaped leaves, you have a type that blooms exclusively on old wood (or branches from the previous year’s summer.)
Make sure you prune in the summer, before august, to make sure none of next year’s bloom buds are pruned off.

Paniculata and Smooth Hydrangeas (pictured)

This method is used for varieties that bloom on new wood, which can be pruned to the ground every fall if desired, and will come back beautifully year after year. Prune back less drastically for stronger stems and bigger blooms, or leave them alone, only pruning down diseased or crossing branches. Whatever your chosen method, though, it’s extremely difficult to prevent these beauties from flowering.

Glossary of Terms

New Wood

New wood are stems that developed on the plant during the current season.

Old Wood

Old wood are stems that developed on the plant since the summer before the current season.

Primocane

A type of berry bush that sets fruit on both new and old wood

Floricane

A type of berry bush that sets fruit exclusively on 2nd year wood

Deadheading

Removing old blooms on a plant is called “Deadheading.” Almost anything with flowers that doesn’t need to set fruit or seeds can be deadheaded, but care should be taken to only pick them on long stems (essentially a type of pruning) if you know that the bloom buds haven’t set.

A good example of this is the difference between roses and hydrangeas. Because they’re stimulated by new growth, roses can be cut fresh at any length, at any point that flowers are available. Meanwhile, many types of hydrangeas only grow on old wood which should be left on the bush for next year’s batch of flowers.

Watersprouts and suckers

Suckers

The term sucker is usually reserved for up through the ground from roots.

Water Sprouts

When the new shoots erupt from above ground wood (visibly growing from the branches or trunk)

Either way, the appearance of these thin, fast growing sprouts is usually regarded as a problem. They take more nutrients and water from portions of the tree with older growth while returning very little benefit to the plant, and the joints between these and the existing plant are generally extremely weak.

What they are, however, is a last ditch effort a plant makes to survive when the parent has been damaged and/or diseased. Consider them a cry for help, and act accordingly.

Final thoughts

Most of this advice boils down to a few rules of thumb: cut away dead or diseased growth, prevent branches from rubbing together or setting at weak angles, and in the case of flowering and/or fruiting trees, shrubs and bushes your pruning times will depend on whether they set buds on new or old growth.

If all of this is making your head spin, though, remember that Newberg Landscape Pros is here to do it all- headache free, guaranteed.