Deadheading catmint is straightforward: once the first wave of flowers fades and the spikes look spent, shear the entire plant back by roughly one-third to one-half its height. That single cut removes the old blooms and triggers a fresh flush of growth and flowers, often within two to three weeks. The technique works because catmint, like many plants in the mint family, is wired to keep producing flowers when you prevent it from setting seed. Getting the timing, tools, and cutting depth right makes the difference between one modest bloom period and two or three generous ones across the growing season.
When to Make the First Cut
Watch the flower spikes rather than the calendar. Catmint’s first bloom typically arrives in late spring or early summer, and each spike holds dozens of tiny tubular flowers that open from the bottom up. Once roughly two-thirds of the flowers on most spikes have turned brown or papery, the plant has passed its peak. That is your window. Waiting until every last flower is dead means the plant has already started channeling energy into seed production, and you lose some of the rebloom momentum.
In most temperate climates, this first cut falls somewhere between mid-June and early July, but your local conditions matter more than a date. A warm spring pushes everything earlier. Cool, wet weather stretches the bloom period out and delays the cut. The visual cue of browning spikes is more reliable than any fixed schedule.
The Shearing Method
For most gardeners, the fastest and most effective approach is a full shear rather than picking off individual flower stems one by one. Catmint grows in dense, rounded mounds, and trying to find and snip each spent spike individually takes a long time and rarely produces better results than a mass trim.
Use hedge shears, large scissors, or even a string trimmer on a low setting for bigger plantings. Grab a loose handful of stems, pull them slightly away from the center of the mound, and cut. Work your way around the plant until you have removed about one-third to one-half of its overall height. You are aiming for a neat dome shape, roughly 6 to 10 inches tall for standard-sized cultivars. Do not worry about cutting into foliage that still looks green. Catmint rebounds aggressively from hard cuts, and the fresh foliage that fills in will look better than the leggy, floppy growth you just removed.
After shearing, the plant will look rough for a few days. Within a week, new growth emerges from the base and along the remaining stems. Within two to three weeks, fresh flower buds appear, and by three to four weeks you typically have a second bloom that rivals the first.
Selective Deadheading for Smaller Plants
If you grow catmint in a container, as a single accent plant, or if you have a compact dwarf cultivar, selective deadheading can make more sense. In this case, you snip individual flower stems back to a set of healthy leaves rather than shearing the whole mound. This preserves more of the existing foliage and keeps the plant looking fuller during the transition between bloom cycles.
The trade-off is time. In a large border planting with a dozen catmint plants, selective deadheading is impractical. Shearing gets the job done in minutes and the rebloom response is essentially the same. Reserve the stem-by-stem approach for situations where appearance during the regrowth period really matters, such as a prominent container by a front door.
How Many Reblooms You Can Expect
In most growing zones where catmint thrives, you can realistically get two strong bloom periods and sometimes a lighter third one. The first natural bloom is the largest, typically lasting three to five weeks. The second flush after deadheading is almost as vigorous and lasts a similar length of time. If you shear again after the second flush fades, a third round of flowers often appears in early to mid-fall, though it is usually sparser and shorter-lived.
Research on repeated harvests of related Nepeta species shows that the plant’s chemical and growth responses shift with each successive cut. A study on catnip cultivars found that essential oil content and overall plant chemistry changed significantly across four successive harvests, and the response depended on the specific cultivar being grown.1PubMed Central. Successive harvests affect the aromatic and polyphenol profiles of novel catnip (Nepeta cataria L.) cultivars in a genotype-dependent manner While that research focused on chemistry rather than flower production directly, it confirms what gardeners observe: catmint does not simply repeat the same performance after each cut. The plant recalibrates, and the later flushes differ from the earlier ones in subtle ways.
By mid- to late September in most climates, it is better to leave the final flush of flowers in place rather than cutting again. The plant needs time to harden off before frost, and late-season cutting stimulates tender new growth that is vulnerable to cold damage.
Why Cutting Back Works Better Than Pinching Off Flowers
Some gardeners instinctively just pluck the dead flower heads and leave the stems intact, the way you might deadhead a rose. This does not work well on catmint. The stems that carried the first round of flowers become woody and floppy, and they rarely produce quality secondary blooms from the same stem tips. What you want is entirely new growth from lower on the plant and from the crown. That requires cutting the old stems down, not just removing their tips.
Shearing back hard also improves the plant’s shape. Catmint has a tendency to flop open in the center after the first bloom, especially if it was not pinched when young or if it is growing in rich soil. Cutting it back resets the mound form and produces a more compact, tidy habit for the second round. The fresh stems that emerge are shorter and sturdier than the original ones.
Watering and Feeding After Deadheading
Catmint is famously drought-tolerant once established, but the period right after a hard shearing is when a little extra water makes the biggest difference. The plant is pushing out a burst of new growth, and dry conditions slow that process noticeably. Give the sheared plants a deep soak after cutting, then water once or twice over the following week if rain does not cooperate.
Fertilizer is less critical. Catmint is not a heavy feeder, and excessive nitrogen produces lush foliage at the expense of flowers. If your soil is reasonably fertile, you do not need to feed after deadheading. If the plant seems sluggish or yellow, a light application of balanced granular fertilizer or a single dose of diluted liquid feed is enough. Overfeeding is a more common mistake than underfeeding with this plant.
Cultivar Differences That Affect Your Approach
Not all catmints respond identically to deadheading, and your specific cultivar matters. The most widely grown garden catmint, often sold as ‘Walker’s Low,’ is a hybrid (Nepeta × faassenii) that reaches about 2 to 3 feet tall and is an exceptionally reliable rebloomer. Shearing it back by half after the first flush almost always produces a strong second round of flowers.
‘Six Hills Giant’ is larger, reaching 3 feet or more, and tends to flop more aggressively. It benefits from an even harder cut after the first bloom, sometimes taking it down to just 4 to 6 inches. The rebloom is reliable but slightly less dense than in ‘Walker’s Low.’ Compact cultivars like ‘Cat’s Pajamas’ or ‘Purrsian Blue’ are naturally tidier and can be deadheaded with a lighter touch, removing just the spent flower spikes without as aggressive a shear.
Studies evaluating related Nepeta species confirm this pattern of cultivar-specific responses. Research comparing catmint varieties grown in Egypt found that essential oil content in the second cut was roughly double that of the first cut, suggesting the plant invests more chemical resources after being cut back.2Annals of Agricultural Sciences. Evaluation growth and essential oil content of catmint and lemon catnip plants as new cultivated medicinal plants in Egypt From a gardening perspective, this matches the observation that catmint’s second bloom often has more intensely fragrant foliage than the first. Specific cultivar genetics shape how dramatically the plant responds, which is consistent with findings showing that successive harvests of different Nepeta genotypes produce markedly different chemical profiles.1PubMed Central. Successive harvests affect the aromatic and polyphenol profiles of novel catnip (Nepeta cataria L.) cultivars in a genotype-dependent manner
Common Mistakes That Reduce Rebloom
Several errors can undermine the rebloom you are trying to encourage:
- Waiting too long: If you let the plant set seed before cutting, it has already started winding down its reproductive effort. The rebloom will be weaker. Cut as soon as most flowers look spent, not after the brown spikes have been sitting there for weeks.
- Cutting too timidly: Taking off just the flower tips leaves behind leggy, woody stems that produce poor secondary growth. Cut deep enough to remove at least one-third of the plant’s height.
- Cutting too late in the season: A hard shear in September or October forces new growth that cannot harden off before frost. In cold-winter climates, stop deadheading by late August or early September and let the final flowers stand.
- Overwatering or overfeeding: Catmint thrives in lean, well-drained soil. Rich, moist conditions produce abundant foliage but fewer flowers. After deadheading, a single deep watering is helpful, but do not keep the soil constantly wet.
What to Do With the Clippings
The pile of stems you shear off is not waste. Catmint foliage is highly aromatic, and the clippings can be dried for use in homemade sachets or potpourri. If you grow Nepeta cataria (true catnip) rather than the ornamental hybrids, the clippings are a treat for cats, though the ornamental Nepeta × faassenii varieties contain far less nepetalactone, the compound that triggers feline euphoria. Toss the stems into the compost pile if you do not want to save them. They break down quickly and do not cause problems in compost the way diseased plant material sometimes can.
Some gardeners bundle fresh catmint clippings and hang them near patios or outdoor seating areas. The volatile oils in the foliage are mildly repellent to mosquitoes and some other biting insects, though the effect is modest compared to commercial repellents. It is more of a pleasant fragrance bonus than a serious pest-control measure.
Catmint vs. Catnip and Why It Matters for Deadheading
Garden centers and plant tags use “catmint” and “catnip” loosely, but they refer to different plants with different growth habits. True catnip (Nepeta cataria) is a rangier, less ornamental species that self-seeds aggressively if not deadheaded. Ornamental catmint, usually Nepeta × faassenii or Nepeta racemosa, is more compact, has showier flowers, and does not self-seed as freely because many popular cultivars are sterile hybrids.
This sterility is actually an advantage for rebloom. Because sterile hybrids cannot set viable seed, they do not shut down flower production the way fertile species do. Deadheading still helps by removing spent tissue and triggering fresh growth, but the plant is already predisposed to keep blooming longer than its fertile relatives. If you grow true catnip rather than a hybrid catmint, deadheading becomes even more important because the plant will aggressively set seed and stop flowering if you let it.
End-of-Season Care and Setting Up Next Year’s Blooms
Once fall arrives and the final flowers are done, resist the urge to cut catmint to the ground. Leave the remaining foliage and stems in place through winter. The dried stems provide a small amount of insulation for the crown, and in cold climates, this makes a difference for winter survival. The dried seed heads, if any formed, also provide food for small birds.
Wait until early spring, when you see new green growth emerging from the base, to do your cleanup cut. At that point, shear or cut back all the old dead stems to just above the fresh new shoots. This spring cut is different in purpose from the summer deadheading cuts: it is about clearing debris, not triggering rebloom. The plant will bloom on its own schedule from the new growth.
If your catmint has been in the same spot for four or five years and is starting to die out in the center or bloom less vigorously, spring is also a good time to divide it. Dig up the clump, split it into sections with a sharp spade, and replant the healthiest outer portions. Division rejuvenates the plant and often restores the generous blooming you remember from its younger years. The divided sections establish quickly and typically bloom well in their first season after replanting.