Are you new to owning a Butterfly Bush and wondering if its behavior is normal? Some of the ordinary seasonal changes a Buddleia goes through can be concerning if you’re not used to them. Spotting genuine problems is a lot easier if you know what “normal” looks like for your plant. That’s why we’ve put together a straightforward guide to let you know what to expect from a Butterfly Bush throughout the year.
Buddleias typically begin to leaf out in the middle of spring and bloom at the height of summer. Their flowering period can last into mid-fall. As the weather turns cold, you can expect your Butterfly Bush leaves to turn yellow and brown before falling off. These plants go dormant in winter and often experience significant dieback.
The seasonal patterns of a Butterfly Bush can vary somewhat depending on how intense your seasons are. For example, in very mild climates, a Buddleia might retain its leaves year-round. In very cold ones, it might not sprout new leaves until spring is drawing to a close. However, the basic seasonal pattern should remain more or less consistent. Let’s take a closer look at how your plant should change throughout the year.
What to Expect From a Butterfly Bush in Spring
New Year’s Day might be in January, but for plants, everything really starts in the spring. That’s when the air turns warm, the sap begins to flow, and life and movement begin to emerge.
A Slow Start
That shift often takes longer to kick in for a Butterfly Bush than for other plants. Many gardeners have experienced a sinking feeling of dismay looking at the gray, leafless branches of their Buddleias amid a sea of greenery.
If you’re seeing this and wondering whether your Butterfly Bush will come back, it’s often best to be patient. You’ll usually spot leaf buds swelling and opening in late April or early May. However, it often takes longer, especially after harsh winters. Most guides will tell you not to start worrying until you reach the middle of June with no signs of life from your Butterfly Bush.
When the leaves do appear, they tend to be oval-shaped, tapering to a sharp point. They’re often long and relatively narrow, though some are more egg-shaped. Butterfly Bush leaves can range in color from forest green to a darker blue-green. Some varieties have a whitish fuzz that can add a silvery note, usually stronger on the underside than the top. The leaf edges tend to be slightly serrated.
Fast Growth
Though it may take a while to get rolling, your plant’s growth should be quite rapid once it’s underway. It will only take a few weeks for those first budding leaves to extend into long, whippy green shoots. They tend to sprout upward and outward, forming a shaggy mound as they spread out.
As the warm weather becomes more firmly established, your Butterfly Bush stems will lengthen quickly. Some varieties can gain a foot or more in a month. Dwarf varieties are likely to be a bit slower.
This depends a little bit on the plant’s diet of sunlight. During the growing season, Buddleias prefer to get at least six hours of direct sun per day. They’ll happily soak up more if they can get it. Slow growth, or leggy growth with pale and widely spaced leaves, may mean your shrub is under-lit.
Limited Predation
Butterfly Bush is not native to the U.S., and there aren’t many things here that like to eat it. You probably won’t see much evidence of deer, rabbits, or caterpillars feeding on your Butterfly Bush in the spring, despite the abundance of tender new shoots.
The main exception is a moth called the Buddleia Budworm. This creature’s caterpillars often lurk inside the developing flower buds and devour them from the inside out. If you see malformed leaves curled into balls at the end of the developing shoots, you might have budworms. That’s even more likely if these clusters are wrapped in silky webbing. See this article for advice on pest treatment.
What to Expect From a Butterfly Bush in the Summer
Summertime is often the season when Buddleias shine brightest. Here’s what you should see during the hottest part of the year:
Big, Showy Blooms
The most important thing most gardeners expect from a Butterfly Bush in the summertime is flower formation. This plant blooms on new wood, meaning that this year’s flower buds only form once growth is underway. They don’t begin to blossom until the height of summer.
The flowering process usually begins sometime from mid-July to mid-August. However, the exact timing depends on how late your plant was to leaf out.
Buddleia blooms don’t form one at a time. Instead, the plant sends out a long spike festooned with tiny flowers, technically called a panicle. They tend to be shaped like lumpy cones or cylinders, though some species generate roughly spherical clusters of blossoms. They often reach 10-15 inches in length, pushing directly out from the ends of the branches.
When they first appear, the flower heads look like they’re covered in green spines. These will deepen to a mature color — typically some shade of pink, purple, or white before the flowers open. Those nearest to the bottom of the flower spike generally blossom first, with the opening movement spreading up in a slow wave.
A Butterfly Bush flower spike will usually remain in bloom for a few weeks before the flowers start to fade. If they’ve been fertilized, the petals will often leave behind tan seedpods as they drop off.
Pollinator Activity
Those brightly colored flowers give off a sweet, honey-like aroma that hints at the abundance of nectar they contain. This should draw hordes of pollinators to visit the blossoms.
That includes the butterflies for which this shrub is named, but it can also include bees, hoverflies, and hummingbirds. Just about anything that likes to sip the sugary juices of flowers will find a tempting meal in the flower spikes of a Butterfly Bush. During the summer months, this plant is typically a riot of activity.
Firmer Stems
Given time to grow, Butterfly Bushes can turn into woody shrubs with peeling gray-brown bark. They don’t usually reach that point in a single season. But the bright green, wobbly stems that emerged in the spring do usually tend to be thicker, darker, and more rigid as summer sets in.
You may notice them turning deeper green or even light brown. They’ll still be fairly pliable, but they should have a bit more stiffness. This process will continue steadily through the fall and winter.
Continued Growth
The rapid expansion of your Butterfly Bush will continue throughout the sunny season. By the time flowers begin to appear, your shrub should have taken on its characteristic shape: a scruffy, rounded mass. The stems typically bow into arcs as the ends are weighed down by the flower spikes.
It’s not uncommon for a Butterfly Bush to reach 6 feet or more in height by the end of summer. If it’s building on a previous season or two of growth, it could be 10-15 feet tall! This varies by species, of course. Some nurseries sell cute little compact Buddleias that never exceed two to three feet in height.
What to Expect From a Butterfly Bush in Autumn
What will happen to your Butterfly Bush as the days get noticeably shorter and the weather gets colder?
Ripening Seeds
As we mentioned earlier, Butterfly Bush flowers tend to get replaced by seedpods as they fade. These plants are pollinator magnets, and they’re self-fertile, so they usually have no trouble getting their flowers fertilized.
Buddleia seed pods are small and roughly almond-shaped, and there’s generally one for each tiny flower. This can leave the flower heads of the plant looking a bit like long pinecones as the season proceeds. They’re light brown at first, but as the summer dwindles into autumn, their color tends to deepen and darken. Their texture also turns dry and brittle.
By late September or early October, these fruits are often ripe enough to burst at a gentle touch. They can release thousands of winged seeds that drift for miles on the wind.
This is one reason why Butterfly Bushes can be invasive in many areas. It’s generally best to clip away the flower heads before the seed pods reach this point. Do this with a sharp pair of bypass pruners that you’ve disinfected with rubbing alcohol.
Continued Blooming
Though Butterfly Bushes may not flower until the peak of summer, they often remain in bloom for quite a while. It’s quite common for new blossoms to continue opening until early October.
Deadheading your plant is a good way to encourage a long blooming period. By removing flowers as soon as they begin to wilt, you allow your Buddleia to put more energy into blossoming.
The length of Butterfly Bush flowering also varies based on the climate. If the weather turns punishingly cold early in the fall where you live, your Butterfly Bush will have a shorter blooming period. The beginning of autumn frost is usually when the plant stops flowering.
Shedding Leaves
Frosty weather also signals your Butterfly Bush to start letting go of its foliage for the winter. Unless you live in the very warmest reaches of the plant’s hardiness range — someplace like southern Texas or Georgia — Buddleia is a deciduous shrub. It will change color and lose its leaves in late autumn.
Sadly, Butterfly Bushes do not offer a particularly eye-catching fall display. Their leaves usually fade to pale yellow, then dark yellow, then brown, before tumbling to earth. It looks okay, but it’s nothing to write home about.
What to Expect From a Butterfly Bush in Winter
For most plants, winter typically means hunkering down and waiting for spring. How will your Butterfly Bush handle the colder months of the year?
Dormancy
When truly cold weather sets in, a Buddleia ceases all noticeable activity. By the time the calendar marks the start of winter, your plant should have lost all of its leaves. The new stems that formed this season should hopefully have firmed up even more. They likely won’t have a woody covering yet, but they’ll be brown and fairly rigid.
If the winter is mild, your Butterfly Bush will simply remain in stasis, waiting for the warm weather to return.
Winter Dieback
Harsh winters take a toll on Buddleias. Any sub-zero temperatures will usually cause at least some damage to the branches, often causing them to die off at the ends. And in USDA Zones 5 and 6, it’s quite possible that everything above ground will die during the winter, leaving only the roots alive.
You won’t necessarily know this until spring rolls around, though. Once you can see which parts of the plant are growing, you’ll be able to spot the dead areas. You can double-check by scratching away a bit of bark and looking for a layer of green, living tissue.
Occasionally, winter damage to a Buddleia will be more dramatic. The stems of the plant get hollow inside as they age. If a branch is cut or snapped off, it can expose the opening, allowing water to trickle inside and freeze. The resulting expansion can cause ice to burst out of the branch, causing extensive cracking and peeling.
Don’t sweat it if your Butterfly Bush dies aboveground and has to grow back from the roots. As we noted above, they’re quite capable of getting big despite the setback.
Planning Your Butterfly Bush Care By Season
Timing can be crucial in gardening, so it’s a good idea to note where various care tasks fall on the calendar. Here’s what you should plan to do for your Buddleia in every season:
Spring:
Extensive pruning and shaping is best done in the spring. Your Butterfly Bush will be dormant but poised to grow back quickly. And since it hasn’t formed any new growth yet, you won’t be chopping off any flower buds. Just wait until after you’re pretty sure the frosts are over.
This is also a good time to transplant your Buddleia from one spot to another. Gardeners who have been preparing Butterfly Bush seedlings or cuttings over the winter can transfer them into the garden in spring.
If you’re going to give your Butterfly Bush any fertilizer, do it in the spring. An inch or two of compost is our usual recommendation. Every couple of years, you can also add a bit of slow-release synthetic fertilizer. This isn’t always necessary, though.
Summer:
Your main task in the summer is monitoring your plant’s soil and making sure it’s getting enough water. For the most part, Butterfly Bushes can withstand dry spells fairly well. But when temperatures are above 90, and you aren’t getting any rain, you may need to give your plant a soak every few weeks.
If you want to take cuttings to propagate your Butterfly Bush, do it in the late spring or early summer. These plants grow best from softwood cuttings — you don’t want to wait until they’re too rigid.
The hottest and driest months are when spider mites tend to strike. Buddleias aren’t especially pest-prone, but mite damage can take a toll. Keeping the plant well-watered helps to stave them off. For more intensive measures, see our article on Butterfly Bush pest control.
Eco-conscious gardeners who want to make sure their Buddleia doesn’t become invasive should also start deadheading in late summer. That’s when the first wave of flowers should be dropping away and leaving seedpods behind. Clip them off and toss them in the trash, not on your compost pile.
Some gardeners like to give their Butterfly Bushes a second overall pruning in the late summer. This can be good if you’re trying to keep the size of your plant in check. Just keep in mind that it may limit reblooming.
Fall:
If you’re deadheading your Butterfly Bush, you’ll likely need to step up your efforts as summer gives way to fall and more and more of the flowers wither. You can also harvest some seed pods if you want to propagate your plant from seed. In that case, you’ll want to let them ripen a bit first. Cover these fruits with paper bags before clipping them, to catch any seeds if the pod bursts.
Early fall is often a good time to plant a new Butterfly Bush. Pest activity tends to be decreased, and with shorter daylight hours, the plant can prioritize root growth over new foliage. Just make sure it will have at least a few weeks to settle in before frost strikes.
Speaking of frost, autumn is the time to make any preparations needed to help your Butterfly Bush survive winter. Laying down some mulch is almost always a good idea, unless there’s enough left over from the previous year. Don’t rake away old, half-decomposed mulch — letting those nutrients get into the soil is a good idea. Just add enough on top to maintain a two to four inch layer.
When you live in a very cold climate, more dramatic winter prep may be called for. Wrapping the limbs in garden fleece may help. If your area is very frosty, you might want to dig up the plant and move it to a garden shed or unheated greenhouse.
Winter:
There isn’t much you need to do for your Butterfly Bush during the winter. Some gardeners like to prune during this period, but this can increase the risk of shattered limbs, as described above. Be alert to the dangers of rain and frost if you’re going to try it.
Buddleias rarely require watering during winter unless you’ve moved them indoors to reduce their cold exposure. In that case, it’s a good idea to water them roughly once a month.
Winter is the ideal season for many indoor tasks related to propagation. For example, you can chill seeds in the refrigerator and then germinate them under grow lights. This helps ensure that the seedlings have grown enough to be ready for transplanting in the spring. You can also rear cuttings indoors over the winter before moving them to the garden.
Final Thoughts
The guide above should give you a rough idea of what to expect from a Butterfly Bush throughout the year. But the details may vary substantially based on the climate, your care habits, and the type of Buddleia you’re growing. There’s no substitute for getting to know your individual plant. And you can only do that by paying close attention to the way your Butterfly Bush changes as the wheel of the seasons rolls along.