Amy Draiss
Beloved for their longevity, the beauty of peonies is something we are understandably keen to protect and enjoy for as long as possible, year after year. If you’ve been growing one for the first time this year, you may have been surprised by its ease of care, thriving with little to no seasonal maintenance. However, you will also know that some of the best perennials rely on careful pruning. By the same token, if you have had your peony for a few years and you are worried that it isn’t looking quite as good as it used to, or maybe didn’t flower all that well this year, you’ll be wanting to get a feel for how to give it a helping hand ahead of the coming year.
Plenty of ornamental plants benefit from routine pruning, boosting overall growth and the production of flowers. Learning to properly prune your peony shrubs at the appropriate time is essential. A few careless cuts can put your peony back potential years in terms of recovery, and in some cases can be a death sentence. Make sure you aren’t making these peony pruning mistakes – put your pruning shears to the best work possible, and you’ll be doing your favorite shrubs a massive service in preparation for the year ahead. Here’s what to avoid in terms of essential fall peony care, and what to do instead to protect your beloved bloomers for the future.
Felco F2 Bypass Pruning Shears from Amazon give sharp precision cuts that are perfectly attuned to your peony stems, minimizing the risk of bruising and letting them heal quickly for healthy shrubs.
Peony Pruning Mistakes You Need to Know
Most mistakes when pruning peonies can be remedied in some way, and the chances are they won’t have a massively negative impact on the long-term health of plants, as long as you intervene. However, problems with peony pruning can slow growth. This often results in poor root development or flower production. This is especially true of younger plants which may be more susceptible to damage done by improper pruning techniques.
Plant size and the severity of cuts will also play a role in determining whether or not plants will recover. As with most gardening tasks, prevention is much better than cure. Pruning is a critical aspect of peony care and knowing how to do it right can reap dividends for years (and hopefully decades) to come. So be mindful of the following mistakes pruning peonies. When you cut back peonies, try to follow the sensible maxim ‘think twice, cut once’ with every potential pruning exercise.
1. Poor Timing
Quite often, the big worry is what happens if you don’t cut back peonies well – but one of the key problems that can catch growers out is making cuts at the wrong time. Mistakes when pruning peonies are often the result of poor timing. Determining the best time, however, will greatly depend upon their type. Most herbaceous varieties benefit most from pruning in fall, after the first frost. However, some may require a trim in early spring. Tree peonies are one such example – if you have a tree peony, you are best trimming just as the buds begin to swell in spring.
Pruning too soon is likely to impact plant growth, preventing shrubs from gathering much-needed energy. Tree peonies are still gathering energy over summer and into fall, even if their foliage is looking slightly worse for wear. Peonies pruned before their foliage has died back naturally may also demonstrate poor bud-set or fail to set flowers completely. So make sure that you are familiar with your peony type, and then act accordingly. You may not even need to prune in fall, but do check.
That said, even if you don’t need to prune peonies in the fall, you can use this time to assess and prep your pruning tools. A good sharpening tool, like Sharpal’s 121N Dual-Grit Diamond Sharpening Stone File from Amazon, can help get your pruning shears and other cutting equipment up to scratch ahead of the actual pruning window.
2. Improper Technique
Knowing how far to cut back peonies, and which parts of the peony need to be left, are important considerations. Along with timing, exact technique will also vary according to peony type. Species which die back to the ground each winter will benefit from aggressive pruning. This occurs when all dead or decaying plant matter is removed back to the ground in fall. Though failure to prune at this time is unlikely to harm plants, it can increase the likelihood or recurrence of disease across beds.
Woody peony types require a very different approach, with the plant's structure trimmed no more than approximately one-third of its height. Excessive trimming of tree peonies can result in serious harm to plants, sometimes leading to their loss. A good clean cut is paramount. If the branch is too thick for your shears, use a saw or a good pair of loppers like the Corona DualLink Extendable Bypass Loppers from Amazon, which are great for higher and thicker cuts.
Improper pruning techniques can result in damage to plants that can take time to rectify. This is a common flowering shrub mistake in general – but certainly applies here. If you’re growing herbaceous types, take care when trimming back shrubs in fall. Deep or aggressive cuts may result in injury to the plant crown or growth eyes just beneath the soil. Damage to these parts may result in poor performance the following spring, with many stems failing to grow or remaining stunted in summer.
Woody species can also be injured by improper pruning. New buds, which begin to swell in spring, will be especially delicate. Each cut should be just above healthy growth, at a 45° angle. Avoid cutting through peony buds, which can result in diminished growth or dieback of the stem.
3. Bad Cutting Hygiene
Poor sanitation is one of the most likely pruning mistakes that ruin peonies, even if these perennials are relatively hardy. Good growing practices will be key in helping peony beds look their best. This is evident in the removal of dead or decaying plant matter in fall and spring, after peonies have been pruned. This will help to prevent disease and the spread of plant pathogens, many of which overwinter in the garden.
Good pruning practices also dictate the use of clean tools to prevent the spread of disease. Cleanliness is essential to maintaining a healthy garden, especially when making cuts from which plants will necessarily need to heal. This is true whether you make cuts in summer, fall, winter or spring. It’s also your first line of defence if you are worried about passing any problems on from one plant to another. Sanitizing tools both before and after the pruning process will aid in keeping plants healthy, working to avoid cross-contamination of infected matter.
Ensure your pruning tools are sterile and cleaned properly after each use. Applications of isopropyl alcohol in concentrations of 70%, such as Dealmed Isopropyl Rubbing Alcohol from Amazon, can reduce the risks of fungal diseases.
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