Plant These In August! 9 Fast-Spreading Perennials That Come Back Every Year

If you planted perennials this spring and they're already looking tired, leggy, or just gone, that's not your fault. That's the nursery's fault. Big box garden centers sell you plants bred for how they look in a pot in April, not for how they perform in your yard in year three. August is when the real gardeners quietly plant the stuff that actually spreads, comes back every year, and fills your yard instead of disappearing after one season. Today I'm covering nine perennials you can put in the ground this month that will fill in your beds fast. And I mean fast. Stick around, because number four is the plant my own grandmother swore by, and almost nobody sells anymore. Number six is a ground cover that outperforms the recommended variety at every single garden center in the country. And the last plant on this list isn't just fast spreading, it's the one plant on here that people tell me years later reminds them of someone they've lost. We'll get there. Let's start the list. Number one is an obedient plant, Physostasia virginiana, hardy zones four through nine. And it makes the list because everyone treats it like a problem instead of a solution. Bloom window runs mid-August into September, with spikes of soft pink to lavender white flowers that look almost like little snapdragons stacked on a wand. Here's the insider mechanic. Garden centers barely stock it because it spreads by rhizome. And rhizomatous plants don't sell well in small pots. They don't look impressive on a shelf. But that same spreading habit is exactly what you want for a bare August bed. Plant divisions 12 to 18 inches apart, water them in deep the first two weeks, then leave them alone. Here's what nobody tells you. It doesn't bloom much its first year. By year three, you'll have a four foot wide colony that needs zero irrigation and blooms for six straight weeks. I put three divisions in my own side yard back in 2019. And by 2022, I was pulling out extras to give to neighbors. Number two is Creeping Jenny, Lysimachia numelaria, zones three through nine. And this one makes the list because most people only ever see it crammed into a hanging basket dying by July. That's not what it wants. Left in the ground, it forms a chartreuse gold carpet that catches light differently than almost anything else in a perennial bed. The insider trick here is planting it in part shade instead of full sun like the tag suggests. Full sun scorches it. Part shade lets that gold color actually hold through August heat. Plant it shallow, barely covering the roots, spaced eight inches apart along a border edge or under taller perennials. The payoff? By year two, it's knitted itself into a living mulch that shades out weeds completely. And by year five, you'll be dividing it to fill in everywhere else in the yard for free. That's two down, seven to go. The next section gets even better. Number three is Black-Eyed Susan, Rudbeckia fulgida goldsterm, zones three through nine. And it makes this list for a reason most people get backwards. Everybody already owns the straight species version and it's fine. But goldsterm is the cultivar plant breeders actually selected for tighter branching and better rebloom. And most nurseries still shelve it right next to the plain version at the same price. Bloom Window is late July through September, with that classic gold-orange petal wrapped around a chocolate-brown center. But goldsterm holds its color deeper into fall, instead of fading to a washed-out yellow. The insider mechanic? This cultivar spreads by both seed and rhizome, so you get fast coverage two ways at once. Plant it 18 inches apart and cut it back hard to four inches in late February, not fall. Leaving the seed heads up all winter feeds finches and gives you a second wave of volunteer seedlings every spring. Here's the mistake almost everyone makes. They deadhead it in September thinking it's tidier. That single habit cuts your following year's spread by half. Leave the seed heads. By year four, one $3 perennial can fill an entire 10-foot bed on its own. Now if you're the kind of person who wants a full season-by-season planting calendar instead of hunting for it one video at a time, that's genuinely the reason I keep this channel going. I put out exactly these kinds of guides every single week, and subscribing just means you don't have to go searching for the September and October follow-ups when they drop. Number four is the plant I mentioned at the top. Creeping Phlox. Phlox subulata, zones three through nine. And yes, this is the one my grandmother grew along her front walkway back in the 1970s, before ground cover was even a marketing term. It's fallen out of fashion because it only blooms once, hard, in April. But almost nobody realizes August is actually the best planting window for it, not spring, because the roots establish through cool fall soil without the stress of blooming at the same time. Color is a carpet of magenta, lavender or white, so dense you can't see a single leaf underneath it during peak bloom. The insider mechanic? Buy it in gallon pots now in August, not in four-inch pots in April when everyone else does. You'll get twice the root mass for barely more money. Space plants 12 inches apart on a slope or wall edge where drainage is sharp. It hates wet feet more than almost anything on this list. The payoff compounds hard. By year seven, what started as six small plants becomes an unbroken sheet of color that needs no mulch, no weeding, and no irrigation at all. Number five is lambs ear. Stachys byzantina, zones four through nine. And it makes the list because people plant it for the texture and completely ignore its second superpower. Everyone knows the fuzzy silver leaves, soft as felt. But almost nobody plants the variety big ears, also sold as Helene von Stein, which spreads faster and almost never flowers, which matters because the flower stalks are what make regular lambs ear flop and look messy by mid-summer. Without them, you get a tight silver-white mat all season instead of a leggy mess. The insider move? Plant it in the worst soil in your yard, the compacted dry patch nothing else survives in, because rich soil actually makes it rot. Space divisions 15 inches apart and don't water it once it's established. Overwatering is the single most common way people kill this plant. In three years, that worst spot in the yard becomes the spot visitors touch first when they walk through your garden. Quick question while we're at the halfway point of this list. Drop your state and your zone in the comments, along with which one of these five you already have growing. I read every single one and it genuinely helps me figure out which of these plants are performing the same way across the country versus which ones behave completely differently depending on where you are. We've still got four plants left, and the back half of this list gets more surprising, not less. Including a ground cover that beats the recommended variety at every garden center. And the final plant on the list, which isn't just fast spreading, it's the one that people tell me years later still reminds them of somebody. Number six is the ground cover I promised. Zones three through nine. Here's the contrarian part. Almost every garden center sells the plain green leafed variety, but the Cultivar Chocolate Chip spreads faster, stays lower to the ground, and actually outcompetes weeds better than its bigger leafed cousin. Yet it's rarely the one on the shelf because the bigger leaves photograph better on a plant tag. Bloom window is May into June, with short spikes of deep cobalt blue flowers rising just a few inches over bronze green foliage. But the real value is what happens the other 10 months of the year. A dense low mat that chokes out crabgrass and creeping weeds without you touching a bottle of anything. The insider mechanic? Plant it in part shade under trees or along a north-facing foundation where grass struggles anyway. That's the spot where Ajuga has zero competition and spreads fastest. Space plugs 10 inches apart and press them in so the crown sits right at soil level. Bury it too deep and it rots. Plant it too shallow and it dries out before it roots. By year two, it's solid. By year five, you'll be cutting sections out with a spade just to keep it from crossing into the lawn. Number seven is lily of the valley. Convalaria mullalis. Zones two through nine. And I'll be honest, this one makes gardeners nervous because they've heard it's too aggressive. That reputation is exactly why it belongs on this list. Bloom window is a tight two weeks in May. Small white bell-shaped flowers with a fragrance so strong it can fill an entire shaded side yard on a still morning. But the real reason it earns a spot here is what it does under deep shade where almost nothing else will spread at all. The insider mechanic? Everybody plants it in dappled shade because that's what the tag recommends. But it actually tolerates near total shade under mature trees better than hostas do and with none of the slug damage. Plant the pips, the little pointed root divisions, two inches deep and six inches apart in that dead zone under your biggest tree where grass has already given up. Here's the mistake almost everyone makes. They plant it near a patio or walkway expecting a tidy little clump. It isn't a clump plant. Give it the worst, darkest, driest corner of the yard instead. And by year 10, it will have carpeted ground nothing else could touch. We are two thirds through this list now and I still haven't gotten to the plant I opened this whole video with. The one that isn't just fast spreading but the one people tell me years later still reminds them of somebody they loved. That one's coming up in the final section so stay with me. Before we get there, if you know somebody who inherited an overgrown yard or someone who just moved into a house with bare dirt beds and no idea where to start, this is the video to send them. These nine plants alone can fill an entire property in three to five years without a single trip back to the nursery. And that's the kind of thing worth sharing rather than explaining twice. Number eight is Siberian Iris. Iris siberica, zones three through nine. And this is where the list starts to shift from fills a bed to something with real weight behind it. Bloom Window is late May into June with blue violet, wine purple, or soft yellow flowers held on thin, wiry stems above grass-like foliage that stays attractive all season, not just during bloom. The insider mechanic most people never learn. Unlike bearded iris, Siberian iris almost never needs dividing for borer damage or rot, which is exactly why it quietly outlasts every other iris in old farmhouse gardens across the country. Garden centers push the flashier bearded types because they bloom bigger in the first year and sell faster. But bearded iris need dividing every three to four years just to survive, while Siberian iris can sit undisturbed for two decades and only get better. Plant the rhizomes just barely under the soil surface, never more than an inch deep, spaced 18 inches apart in a spot with consistent moisture. The stakes here are different from everything else on this list. This isn't a plant you're managing for five years. It's a plant you plant once and your kids inherit the clump. And that brings us to number nine, the plant I opened this video with. Peony. Paeonia lactiflora, zones three through eight. And if you've ever wondered why the peonies at an old farmhouse or an abandoned homestead are still blooming 40, 50, 60 years after everyone who planted them is gone, this is why it closes the list. Bloom window is a short, spectacular two to three weeks in late May with blooms in blush pink, deep magenta or pure white, often carrying a fragrance closer to citrus or rose depending on the variety. Dense enough that a single stem can fill a room. The insider mechanic almost nobody tells you, peonies fail for most people not because of soil or sun, but because they're planted too deep. The eyes, those small pink buds on the root need to sit no more than two inches below the soil surface where the plant will grow lush green foliage for years and simply refuse to flower. Plant the roots this month in August while the soil is still warm enough for roots to establish before frost, spaced three feet apart to account for the size they'll reach because they will reach it. Here's the part that matters more than any other plant on this list. Peonies don't perform for you, they perform for whoever tends that ground next. The clump you plant this August at two feet wide will be six feet wide in 20 years and it will very likely still be blooming long after the reason you planted it has become a memory instead of a person. That's the full nine from obedient plant quietly filling in your first bare bed all the way to a peony that outlives everyone who ever admired it. My grandmother's creeping phlox is still blooming along that same walkway every April on a property that isn't even in our family anymore. Somebody else waters it now and they have no idea what it means to somebody. If you've got a plant like that in your own yard, something still blooming years after the person who planted it, I'd genuinely like to hear about it in the comments along with your zone.