Simple Seasonal Maintenance: When To Prune And Why
If you own a garden, you know that you need to cut back and prune certain plants throughout the year- but if you are like me, you stare at the variable mix of perennials, annuals, vines, roses, bushes, and whatever is growing in the corner that you keep because it has pretty flowers… throw down your pruning shears, and walk away. Why? Because you’re always afraid you’re going to do something wrong at the wrong time and kill the plant forevermore.
Until now. I’ve compiled a simple list of the most common plant categories found in your garden, and broken it down into seasonal pruning times to help simplify this process, and make it an easy, and even, enjoyable task.
- Ornamental Grasses
- Semi-Woody Perennials
- Broad-leafed Evergreens
- Summer and Autumn Flowering Trees and Shrubs
- Reblooming and Paniculatas Hydrangea
- Evergreen Shrubs
- Spring Flowering Shrubs
- Old Growth Hydrangea
- Flowering Annuals
Why Does Vegetation Need to Be Pruned?
Most plants prefer a pruning of some sort through the year to help remove dead or dying material, help promote new growth, and keep it under control. The issue that always arises is – when? Even if you do prune incorrectly, generally this isn’t a fatal mistake and the plant will recover just fine through the season.
Be sure to prune using the correct tools that are in good shape, to avoid causing long healing wounds and opening up your vegetation to bugs and diseases. Hand pruners and loppers are the most popular and easily used to take care of everything but the most difficult of heavy pruning and cutting.
Early Spring Pruning
When approaching pruning methods, a good start is to remove any dead, dying, or mis-shapen parts of your plant before getting down and dirty with pruning for the overall health and production of your garden. Pruning promotes new growth, and in the case of flowering vegetation, this equals more blooms for you to enjoy through the season! Many plants benefit from early spring pruning that occurs after the last frost and either immediately before or after the first flush of growth begins to show. Below is a list of the most common garden plants that could use some attention each spring:
Ornamental grasses grow in a similar nature to your lawn, so you will want to get these cut down fairly early in spring to allow new growth to receive the warmth and nutrients from the sunlight it needs to promote new stems. To simplify this task, tie together the dead growth from the previous year after the last frost, and then cut as close to the ground as you can without cutting any new growth you may notice. In climates that have frosts well into the early growing season, old stems can protect any new growth that may have started so be sure to pay attention to how your grasses are growing.
Semi-woody perennials include plants such as Butterfly Bushes and Russian Sage, two popular bee and butterfly attractants that can put out hundreds of flowering heads each season with the correct pruning techniques. Depending on what varieties of plant you have, you can cut these to about 4 inches from the ground each year to promote new stems, and be rewarded with a healthy flush of flowers beginning in early summer.
Larger varieties of these that can grow up to ten or more feet high can be cut back to a few feet from the ground as well- but they do equally well by simply cutting lateral branches to your desired shape, and the stems of last year’s spent heads to where the nearest notch below it. After the season’s blooms have died, try cutting these off to promote new growth in warmer climates – many times they will reward you with a second flush of blooms in early fall.
Certain broad-leafed evergreens need some pruning come spring. Boxwood and Holly plants fall into this category and they can often show winter damage, especially in Northern climates- and so a spring clean-up is required. Removing these dead spots provide new light into the canopy and allow for new growth to sprout through.
If you are looking to shape these plants into hedges or other ornamental contours, wait until later in spring so rapidly growing new shoots will quickly fill in the areas you’ve cut away. The great thing about these evergreens is that they can take heavy pruning fairly easily in order to shape them into your desired look. Rule of thumb, however, never take more than a third of the bush at any one time to avoid undue stress, and the removal of too many of the leaves that provides food to the roots for survival through the winter.
Summer and Autumn Flowering Trees and Shrubs
Not all plants benefit from pruning, and flowering trees and shrubs (such as fuchsia and spirea) are often left alone except for the occasional removal of dead or dying branches, which can be done at any time of year. But if you need to keep the shrub’s shape under control, or within a confined space, then pruning back your summer flowering trees and shrubs to promote flowering growth is ideally done in the early spring.
This is only helpful however if you species flowers from new growth. If it flowers on old growth, you will want to avoid pruning until after the flowers are spent. Take care not to ever take more than one third of the tree to provide a good canopy to root ratio, since the purpose of the trimming is to cause a flush of new flowers.
After pruning, an application of nitrogen rich fertilizers and good watering will help develop the new stems and flowering buds.
Reblooming and Paniculatas Hydrangea
As with flowering trees and shrubs, cutting back your hydrangea really should be avoided unless you need to get it under control, or if it hasn’t been blooming well in order to stimulate growth. Before you take the shears to your hydrangea, be sure to check your species for what type of hydrangea it is. Reblooming varieties put forth new flowers on both old and new stems, so trimming back spent head come spring may remove some new buds, but it also will stimulate even more new growth and flower buds. Paniculatas varieties bloom only on new growth, so they benefit from a pruning every year or so as well.
As with most vegetation, removing old flower heads and dead or broken stems first should be the priority. After that consider which stems you should cut, never taking more than a third of each, and always leaving at least two, or more, of the old growth stems intact.
Roses love to be cut since they flower on new growth. In fact, cutting your roses continually through the season after each flush of blooms (for continual, or repeat bloomers) you will keep them coming all summer long and well into the fall. Be sure to feed your roses though, since those blooms take a lot of energy to produce!
Start your initial trimming in spring after you first notice the start of new growth. Remove any dead branches, old rose hips from the previous year, low branching stems, or any branches not producing new growth. Also clean out the middle of your bush since roses thrive on sunlight, and shady areas get damp easily and promote a variety of horrid mildews and other diseases you don’t want to have to contend with.
Once you have cleaned it up, trim back last years old growth to the section of new growth to allow it to boom upwards and make sure the nutrients go right to where you want it. If you don’t cut your roses for bouquets, deadhead each stem to the double 5-leaflet where new growth will eventually appear.
Keep in mind that old fashioned varieties and climbers are best left alone except for the removal of winter-kill, or to thin slightly if they have become overbearing.
Clematis are a tough vine to figure since they fall into one of three categories, and trimming back at the wrong time of year can result in a loss of flowers for the season. Trimming is part of their general care though to keep them under control, and to allow for healthy new growth. If in doubt, leave your clematis alone, at least for the first few years to get a good idea about when it flowers, and consequently, when it should be trimmed.
Late summer and fall bloomers fall into category 3, which mean they bloom off of new growth, and these vines can be cut back to a foot from the ground each spring just before or after new growth begins. They are generally very vigorous climbers and will cover your growing structure again fairly quickly before setting new blooms, but if you aren’t keen on cutting it back so much, you can simply cut to your desired height. Keep in mind that the lower the new growth begin, the lower flowers you will have later on.
Early Summer Pruning
This is the perfect time of year to cut back, trim, and shape your evergreen shrubs, such as yew and juniper species. You can also take clippers back to your broad-leafed evergreens now that you can see exactly how the new growth is coming in. Sucker stems will be noticeable by this point as well and should always be removed so nutrients move to where you need it into the upper canopy.
Waiting to trim until the first flush of new growth is evident is ideal because any open areas in the bush will be covered back up with this growth. It also provides for a consistent growth so you can have symmetry if that is what you are shaping for. Don’t forget to get into the inside of your bush as well to clean up dead branches and old needles that are shedding. This also helps keep any bugs or diseases from taking root in the cooler recesses of the interior.
Spring flowering shrubs and woody plants, such as forsythia, lilac, and rhododendron, profit from a trim in the early spring directly following their flowering. If you put off your cutting, it’s best to avoid cutting at all since these plants bloom on the previous summer’s growth, and you don’t want to accidentally remove everything directly responsible for the following years flowers.
Deadheading flowers immediately also help keep the plant from forming seed heads, forcing those nutrients into the new growth rather than propagation, which equals more abundant blooms for you later on! Regularly removing several of the oldest stems each year will also help your plant maintain size and shape.
If you happen to have completely overgrown bushes, such as forsythia or lilac, you can cut these down to within 6 inches from the ground to rejuvenate the entire plant and start from a blank slate!
As mentioned above, be sure to determine your type of Clematis. Just because it blooms in spring doesn’t mean it isn’t a continuous bloomer and is finished for the rest of the season. Category 1 Clematis are only spring bloomers and though the cutting back of the plant immediately following the spring flush of blooms, you will be allowing your plant to put the nutrients it would use for seed into new summer growth, and next year’s flowers.
If your Clematis is a vigorous climber, you may want to consider cutting back almost to the ground since it will quickly cover your support through the summer. Plus, the higher the new growth is, the higher your blooms will be. Usually you will want to enjoy them at at least eye height, so keep that in mind during your pruning process. If you are unsure, simply let your vine grow until you know!
Mid to Late Summer Pruning
As mentioned above, continual blooming roses benefit from consistent deadheading to allow new growth to break through and form new buds. Either cut roses for flower arrangements, or simply remove the spent heads to stop the formation of rose hips. Be sure to take care to cut only to the 5-leafed stem in order not to cut off where the newest bud is most likely forming. And a 45 degree angle cut is generally the easiest and least stressful to the plant.
If you have only one time bloomers (many older varieties), you’ll want to deadhead these as well, always making sure to cut above the new bud formations. Cleaning out dead or necrotic wood is also a must to keep it from spreading. This can occur for many reasons, but can be easily taken care of at any time of year.
Most hydrangeas fall into this category, and only bloom on old growth. If you are unsure of which your plant it, either try to identify it (local extension offices can be very helpful with this), or wait a season to see when and where it is blooming from. These flower buds form on the growth that is set each summer, so to cut at any time other than immediately following bloom could result in the accidental removal of next year’s flowers.
Most people enjoy the winter interest spent heads lend to the garden, so if you haven’t cut them for arrangements, feel free to prune around these stalks. In all honestly however, hydrangea do best when left alone. Trim only if you see material that needs to be removed, or if you need to get it under control. If your plant is over 5 years old you can rejuvenate it by cutting it back by one-third.
Annuals are planted to lend color and variety to a garden for a season, upon which they die at first frost and must be either propagated and planted the following year, or rebought (and planted). Obviously keeping them in bloom and hardy during one short season needs to be a priority, and so consistent deadheading is a must. Make it a priority once a week to look over our annuals and remove spent flowers or seedheads by cutting them stem to the next lateral bud (the next stem or leaf on the stalk.
To encourage more, albeit smaller, blooms, pinch off the terminal bud at the tip of the stalk before bloom. This will encourage more flowers to form on the stalk, hence more color for your garden! Don’t apply this practice more than two or three times a season though or the growth may go to uch into vegetation and the plant will become too dense.
The most attention you’ll want to pay to in your garden is to your perennials. Through the season it is smart practice to remove dead stems and spent blooms, but after the first frost feel free to cut back to a few inches above the ground any vegetation that is left over. If you prefer to leave it for winter interest, you can wait to cut until spring, but this maintenance can be taken care of as long as the season’s nutrients have gotten into the roots to ensure the plant’s survival through the winter.
I do find I like to clean up the garden in the fall, but will leave a few choice perennials alone that have strong stalks or thick standing leaves for winter garden interest. Otherwise, cutting stems to about 6 inches from the ground generally leaves some winter and new growth protection come spring, and eventually composts back into the ground easily enough. This practice also reminds you of where you have late emergers come spring so you don’t accidentally dig it up or replace it forgetting where it has been
Winter pruning is an good choice for larger trees and bushes in order to better see the branches, that and they are dormant so you are not interrupting any growth. Other than pruning your fruit trees (please follow the link to the article concerning the Benefits of Pruning Fruit Trees), all deciduous and evergreen trees can benefit from a trim in the winter if it is needed for overall shape and health.
Deciduous Trees and Evergreens
Trimming your mature trees should be for maintenance only and with an eye for health. The first thing you want to do is be sure to remove dead and dying limbs, broken branches, limbs that cross walkways or create a hazard because of placement, and anything rubbing up against each other.
Winter pruning has a few added benefits as well, not only can you see the structure of the trees better in the case of deciduous species, you also reduce the risk of spreading disease or drawing in insects. Thinning the canopy if it is very thick helps get sunlight into the interior to make better use of those leaves come summertime. When doing this, start on the inside and work your way out, only removing a branch or two at a time before stepping back to ge the overall effect. Keep in mind to always trim back to a bud or branch to keep suckers from forming.
Better Your Garden With The Correct Techniques
Although the above is just a brief run through of the the general pruning seasons, always be sure to correctly identify your vegetation before you take a set of pruners to it. Pruning, when done right, can help keep your plants growing how you want them, and keep flowering buds a priority. Hopefully this has been a valuable article to organize your garden maintenance schedule in a less stressful manner -and keep happy blooms year after year!
As always – if you found the information interesting, have any specific questions concerning your plants and climate, or have anything to share, please comment below!
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