Some hydrangea species, known as “old wood,” bloom on growth from the previous year. The flower buds that will bloom in the upcoming summer are present in this old wood. We would have a plant without flowers this year if we pruned in the winter or spring because we would lose the flower buds. As a result, many cultivars undergo pruning following summer blooming.
The young growth that appears in the springtime bears flower buds when hydrangeas that bloom on new wood are present. These plants can be clipped in late winter or early spring before new growth starts because the buds are not present during the winter months.
Do hydrangeas bloom on fresh growth or older growth?
On the growth from the previous year, shrubs like hydrangeas flower in the middle to late summer. Mophead and lacecap hydrangeas can bloom well with minimal care, but routine pruning promotes fresh, healthy growth that can result in more impressive displays.
Newly planted hydrangeas will they bloom?
There could be a number of causes for hydrangeas not to bloom. Since we can grow five different species of hydrangeas, some explanations vary based on which type it is.
But first, let’s cover the broad causes. The bush might not be fully developed for blooming. The majority of woody plants don’t bloom until they are rather mature. If a newly planted bush had flower buds when it was in a pot, it might bloom the first year. However, after that, it might not bloom for a year or two as it gets used to the soil in its new position. Instead of flower buds, it is actively forming new roots and branches. There will be a lot more flowers when it eventually starts to blossom again because the bush has indeed “bushed” out!
Sadder still, it’s possible that deer have devoured the flower buds. Where deer have pulled the buds off because they lack incisors, look for rough torn stem ends. Additionally, because all hydrangeas require moisture to thrive, blossoming may not take place if a drought strikes at the incorrect time.
The timing of some hydrangea pruning by gardeners has been off. At this point, determining the species becomes crucial. We have two species that flower on fresh wood (new growth of the current growing season). These include the panicle hydrangea, Hydrangea paniculata, also known as the PG hydrangea, which is frequently seen densely planted in cemeteries, and the native smooth hydrangea, Hydrangea arborescens, which is frequently sold under the cultivar name “Annabelle” and typically has white mophead flowers. Early spring is a good time to prune these two species, and the new growth will bloom later in the summer.
Our other three hydrangea species, however, only flower on aged wood (growth from the previous growing season). The native oakleaf hydrangea, Hydrangea quercifolia, with stunning crimson or maroon fall foliage color, the climbing hydrangea, Hydrangea anomala petiolaris, a fantastic vine for partial shade, and the majority of the highly popular blue or pink bigleaf hydrangea, Hydrangea macrophylla, are included. The flower buds will probably be removed if these plants are pruned in the fall or early spring. It is preferable to prune immediately following blooming, before the new flower buds emerge.
The bigleaf hydrangea has undergone a number of new types over the past few years. They bloom on both old and new wood, hence the name “remontant.” Growing these types will help one prevent a further cause of poor bloom. Flower buds on older, non-remontant types of Hydrangea macrophylla frequently die in our cold winters. However, gardeners who reside in urban areas or close to bodies of water, where the winters are less severe, frequently have success with these types. A winter with a thick layer of snow may also adequately shield the flower buds from the cold in rural areas.
Bloom on new and old wood: prune anytime
These grow and blossom both this year and in prior years. While blossoms that sprout on current season growth flower later and continue through the end of the season, “old wood buds provide early season color. Deadheading spent flowers and removing weak or dead stems are all that’s truly required.
What occurs if hydrangeas are not deadheaded?
Deadheading too-tall hydrangeas can occasionally be challenging. Your other option is to keep them on if you don’t have the skills to reach spent flowers or all of the spent blooms. And you can do that without suffering too much harm.
Simply omit deadheading hydrangeas, and your plant won’t suffer. At least nothing major enough to need worrying about.
Your hydrangea might not produce as many or as large of blooms as it would have if the spent blooms had been removed. It will nevertheless continue to bloom.
Having said that, you can think about pruning hydrangeas that have gotten too tall in order to make them smaller and easier to handle.
This will make it simpler for you to maintain the tidy appearance of your hydrangeas. Additionally, it will make it simpler to remove spent blooms from plants and promote future blooms with greater vigor.
Many customers ask why their hydrangeas aren’t blooming. The primary reasons hydrangeas don’t bloom are incorrect pruning, bud damage due to winter and/or early spring weather, location and too much fertilizer.
There are hydrangea kinds that bloom on either fresh or old wood, or even both. Both new and old wood are the growth of the following year (spring), respectively.
- Consider that this year, you bought a Nikko Blue Hydrangea. For the next year, Nikko’s produce blooms in the fall. Your Nikko is therefore creating blooms this fall that will blossom in the spring.
- Therefore, you wouldn’t want to completely prune your Nikko Blue Hydrangea this fall while you are pruning your perennials. Pruning the Nikko Blue Hydrangea this fall would effectively mean cutting off your hydrangea flowers for the upcoming spring.
- The idea behind Endless Summer, a hydrangea variety that blooms on both old and new wood, is that the plant will set blooms this fall to blossom not only in the spring of the following year, but will also keep producing blooms in the spring of the following year to extend the blossoms into the summer.
- Once more, pruning your Endless Summer hydrangea in the fall would mean removing some of the flowers that would blossom in the spring.
The hydrangea’s plant tag will indicate whether it blooms on fresh wood, old wood, or both. It is typically preferable to wait until spring to prune your hydrangeas. As the plant grows, you’ll see stems that are fragile when bent and lack any leaves. Since these stems are dead and won’t produce any flowers, they should be clipped close to the plant’s base.
The second reason why your hydrangeas aren’t blooming is probably the weather. Buds of hydrangeas are extremely susceptible to cold. Therefore, it is a good idea to wrap your hydrangea for the winter if it is an old wood hydrangea. Keep in mind that old wood hydrangeas establish their blooms for the following spring in the fall. Therefore, you won’t have blossoms in the spring if the fall-produced buds are frozen in the winter.
You can wrap anything with regular burlap. Burlap should be wrapped around the plant and filled with mulch or leaves after the first hard frost and after the hydrangea’s leaves have dropped. In order for the buds to survive the winter and sprout the following spring, the plant receives insulation from this. Never wrap your hydrangeas in plastic. When warmer winter days arrive, the plant cannot breathe since plastic, unlike burlap, doesn’t breathe. As a result, the plant can heated to such high temperatures that it cooks within the plastic and perishes.
The second most frequent weather-related cause hydrangeas do not blossom is late spring killing frosts. We saw really chilly temperatures in April both this year and last year after beautiful spring days. When springtime temperatures drop below freezing, hydrangeas need to be covered with an old beach towel or sheet. Because of the temperature dip, there won’t be any blossoms.
The majority of hydrangeas require at least 3 to 4 hours of light per day to bloom. The best light is in the early morning, midday light is acceptable if it is dabbled light rather than beating sun, and afternoon sun is typically too hot. Check the plant label, though. Newer hydrangea cultivars are being created that can withstand more sun exposure time and sun intensity. A hydrangea in full sun will require much more watering than one in diffused light, so keep that in mind.
High nitrogen fertilizer should not be used to feed hydrangeas. Nitrogen is indicated by the first number on the fertilizer ratio. (The ratio stands for N, P, and K) For healthy leaves and general good growth, some nitrogen (N) is required; however, a ratio of 8-16-6 or any similar combination with a higher middle or phosphorus (P) value is preferred. The growth of roots and shoots is encouraged by phosphorus, which improves the blooming process.
Potash (K), the third element’s last quantity and the lowest ratio, is for plant hardiness. Because hydrangeas prefer acidic soil, they can be fertilized with fertilizers designed for such plants. Hydrangeas only require fertilizing twice a year, once in early spring and once in mid-summer. To avoid root burn, make sure the soil is always moist before applying a fertilizer.
What does it indicate when fresh wood blooms?
The secret to success is timing the pruning of your plant. You’ll undoubtedly miss the plant’s flowers for that season if you cut a flowering shrub at the wrong time of year. Even if the plant will return and bloom once more the next year, this is not the end of the world. The major reason why most people avoid pruning their shrubs is probably the possibility of missing out on a season’s worth of flowering. The good news is that trimming shrubs improperly nearly never results in plant damage.
If your shrub flowers on new wood or on old wood, you need to know when to prune it to avoid disrupting its blooming cycle. These two phrases are frequently used, however they are rarely clarified in clear language. This is what they signify:
When a plant flowers on fresh wood, it signifies that it does not produce bloom buds until after spring growth has started. The flower buds that will later bloom that year will be developed by the shrub’s new growth—or rather, the new wood—that season. Usually, flowers appear later in the growing season on plants that flower on new wood. Roses, Rose of Sharon, Panicle Hydrangea, and Butterfly Bush are a few examples of plants that flower on new wood (see photo “Miss Molly” at left).
When a plant grows on old wood, it is forming the flower buds for the upcoming year’s blossoms now. On the old wood from last year’s growth, the buds are carried through the winter. These plants start developing the flower buds for the following year as soon as they finish blooming. Typically, plants that bloom on old wood do so early in the growing season. One extremely significant exception to this rule, though, is the bigleaf hydrangea found in the Cityline or Let’s Dance series. On aged wood, they bloom from mid to late summer. Forsythia, lilac, and weigela are a few further examples of plants that bloom on ancient wood (picture Show Off, below right).
The majority of your pruning should be done in the spring, but which part of spring? Early in the spring, while new growth is starting, you can prune plants that flower on fresh wood. They have plenty of time to recover from pruning while still producing flower buds that will blossom in that season as a result. This should be done after the stems have sprouted buds but before they enlarge. By pruning before the buds leaf out, you can identify where the healthy new growth is located and prevent the plant from wasting energy on buds that you will eventually have to remove.
After flowering is complete, plants that flower on old wood can be trimmed. The flower buds will be lost if you cut the plants before they bloom. They might not have enough time to produce flower buds for the following year if you wait too long after their blooming period is through.
Several reblooming plants are available from us, including the Bloom-A-Thon azalea, Sonic BloomTM weigela, and Bloomerang lilac. The optimum time to prune reblooming plants is right after their initial wave of bloom, which happens on the old wood. Because reblooming plants can flower on both old and new wood, this is the greatest time to prune them. This gives them plenty of time to put on new growth in preparation for their rebloom while also allowing you to enjoy their spring display. They only need a light trim to put on new growth after their initial bloom, but don’t worry if you fail to do it—you’ll still receive a fantastic second show!
You may always remove any dead or damaged wood from a shrub. Just make sure it is dead before you do it! It can be easy to believe a plant is dead or has to be pruned, especially in the early spring, but it’s best to put the pruners away and wait to see if any buds appear. Damaged wood can also be removed at any time, as well as growth that obstructs walkways or makes it difficult to get to a particular part of your yard. All of the other pruning recommendations are secondary to safety.
Keep in mind that trimming is not always necessary for shrubs to perform effectively and blossom. Skip the pruning if you’re unsure what to do or if the plant’s size and performance last year satisfied you.
Cut back these shrubs in late winter before new growth begins
Shrubs that flower on young wood typically start blooming later than old-growth bloomers, beginning in June and continuing until the first frost, because they need to grow and set buds the same year that they bloom. As long as you avoid trimming when the flower buds are opening, these shrubs are understanding if it is not done at a specific period.
1. Trim the flowers all the way back for larger blooms.
These bushes can be completely removed from the ground in late winter or the beginning of spring. If cut severely like this every year, smooth hydrangeas will produce much larger flowers, but many gardeners prefer smaller blooms on stronger stems.
2. Maintain an old growth foundation to lessen flopping
Especially after watering from above or after a heavy storm, the branches of some hydrangeas frequently topple over from the weight of their blooms. Cutting the stems to a height of 18 to 24 inches will help to reduce this flopping by creating a strong framework for fresh growth.
Janet Carson is the University of Arkansas Cooperative Extension Service’s horticulture specialist.
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