Every August, I start paying a lot more attention to my mums. Around here in the Midwest, that stretch from early August into Labor Day is when these plants either set themselves up for a gorgeous, full-on fall show or quietly disappoint you with a few sad blooms and a lot of floppy stems. I’ve learned this the hard way more than once, especially in years when work got busy and I assumed a little rain and good intentions would be enough. It wasn’t.
If you want mums that absolutely glow on your porch, front walk, or garden beds by September and October, August is the month to get serious. Whether you planted hardy mums in the ground last spring or you picked up potted mums early and want to keep them looking lush, there are a handful of very specific things that make the biggest difference. Here’s exactly what I do in August to encourage bigger plants, more buds, richer color, and a much longer bloom window.
1. Stop pinching at the right time
This is the big one. If you’ve been pinching back your mums through summer to keep them compact and bushy, August is when you need to stop. In most of the Midwest, I aim to stop pinching by late July or the first week of August at the absolute latest. If you keep pinching too long, you remove the developing flower buds and delay blooming so much that your mums may not peak until very late fall, or they may get hit by frost before they really perform.
Pinching is simple: you remove 1 to 2 inches of soft new growth from the tips of the stems. That encourages side branching and gives you a fuller, rounder plant. But by August, the plant needs time to shift from leafy growth into bud formation. If your mums still look a little uneven when you stop, don’t worry. A slightly imperfect plant in August usually turns into a much better bloomer in September than a heavily pinched one that never gets a chance to set buds.
2. Water deeply and consistently, not randomly
Mums are thirstier in August than a lot of people realize. Hot days in the 85 to 95 degree range, dry wind, and pots heating up in the afternoon can stress them fast. When mums get too dry, buds can abort, lower leaves turn yellow, and the whole plant loses the dense, healthy look that gives you that “massive color” effect later.
For mums planted in the ground, I try to give about 1 inch of water per week minimum, and closer to 1.5 inches during a hot, dry spell. If I’m watering by hand, that usually means a slow soak for 10 to 15 minutes at the base of each large plant, 2 times a week instead of a quick daily sprinkle. For potted mums, I check them every single day in August. On very hot days, especially with 10- to 12-inch nursery pots, I’ve had to water once in the morning and again in late afternoon.
The goal is evenly moist soil, not soggy soil. If the pot feels feather-light, it’s too dry. If the soil is swampy and smells sour, you’ve gone too far the other direction. I always water at the base and avoid soaking the foliage in the evening, since damp leaves overnight can encourage disease.
3. Feed lightly with the right fertilizer
August is not the month for heavy nitrogen feeding. If you dump on a lawn-type fertilizer or anything too high in nitrogen, you’ll push soft green growth when the plant should be focusing on buds and bloom development. That can leave you with big leafy mums and fewer flowers.
If my mums were planted earlier in the season, I like to give them one final light feeding in early August with a balanced fertilizer such as 10-10-10 or 5-10-5, used at half strength. For water-soluble fertilizer, I follow label directions carefully and usually err on the weaker side. For granular products, I apply sparingly and water it in well. Once buds are forming clearly, I stop feeding altogether.
If you bought mums already loaded with buds from a garden center, skip fertilizer unless the plant has clearly been sitting in the same pot too long and looks depleted. Overfeeding a budded mum right before bloom is one of those “seems helpful, actually isn’t” moves.
4. Give them full sun, even in late summer
Mums need at least 6 hours of direct sun a day, and 8 hours is even better if you want dense bud set and strong stems. In August, I pay attention to whether nearby annuals, vegetables, or even patio umbrellas are casting more shade than they were in June. It sounds silly, but I once realized my nicest mum container was getting cheated out of morning light because I’d moved a deck chair and umbrella setup for a family barbecue and never moved it back.
If your mums are in pots, this is easy to fix. Shift them to a spot with bright morning sun and solid afternoon light if possible. If they’re in the ground and getting less than 4 to 5 hours of sun, they may still bloom, but they probably won’t give you that packed-with-color look the headline promises. More sun generally equals more flowers, better branching, and richer fall color.
5. Clean up yellow leaves and dead interior growth
By August, mums often have some tired growth near the base or in the center, especially if they’ve grown quickly in humid weather. I take 10 minutes with clean pruners and my fingers and remove yellowing leaves, snapped stems, and any dead twiggy growth hiding inside the plant. This improves air circulation and makes it easier to spot pests early.
I don’t mean hacking the plant back hard. I mean basic grooming. If a stem is clearly dead, take it out at the base. If leaves are yellow and drop off with a light tug, remove them. If there’s a clump of crowded foliage pressed so tightly together that it stays damp after watering, thin just a little. It’s a small chore, but it keeps the plant healthier and helps direct energy where you actually want it: into those buds.
6. Check for aphids, spider mites, and caterpillars before they multiply
August pests can sneak up on you. I’ve had mums look fine from three feet away and then, once I got my coffee and bent down for a closer look, I found aphids clustered around new growth and tiny webbing from spider mites underneath the leaves. Either one can weaken a plant fast during hot weather.
Here’s my quick inspection routine: once a week, I check the stem tips, the undersides of leaves, and around any forming buds. Aphids usually show up as little green, black, or brown pear-shaped insects. Spider mites are much tinier and often come with pale stippling on the leaves. Caterpillars leave chewed edges or little dark droppings.
For a light aphid problem, a sharp spray of water in the morning is often enough if you repeat it every few days. For bigger infestations, insecticidal soap works well when used according to label directions. Spider mites often improve with better watering and humidity around the plant, plus repeated washing of the foliage. I always avoid spraying in the heat of the day when temperatures are over about 85 degrees, because tender leaves can scorch.
7. Make sure potted mums are not root-bound and starving
This is especially important if you bought mums early or carried over nursery plants from spring. A mum that has filled its container with roots can dry out incredibly fast in August. Water runs straight through, the soil shrinks away from the sides, and the plant starts acting stressed even if you think you’re watering enough.
If you slide the root ball out and see thick white roots circling heavily around the bottom and sides, move it up one pot size, usually 2 inches wider. So, if it’s in a 10-inch pot, go to a 12-inch pot. Use a high-quality potting mix, not garden soil. I like to loosen the outer roots gently with my fingers before replanting, then water deeply until excess drains out the bottom.
If repotting feels like too much in late summer, at least soak the pot thoroughly and monitor it closely. But honestly, when I’ve taken the time to repot a badly root-bound mum in early August, the payoff in bud retention and plant vigor has usually been worth it.
8. Mulch in-ground mums to keep roots cooler and moisture steadier
For mums planted in garden beds, a 2-inch layer of mulch can make a real difference in August. It helps the soil hold moisture longer, reduces temperature swings around the roots, and cuts down on weed competition. I use shredded hardwood mulch most often, but chopped leaves or clean straw can also work nicely.
Keep the mulch about 1 to 2 inches away from the stems so moisture doesn’t stay trapped right against the crown. That little gap matters. Piling mulch directly on the crown can invite rot, especially if you get humid nights and frequent summer storms. A neat mulch ring also makes watering easier because the water goes where you want it instead of running off hard, dry soil.
9. Rotate containers every few days for even growth
If your mums are in decorative pots on a porch, stoop, or patio, they usually lean toward the strongest light source. By August, that can create lopsided plants with one side fuller than the other. I rotate my containers a quarter turn every 3 to 4 days. It’s one of those tiny habits that sounds fussy, but it really does help create a rounder, more balanced shape.
This is especially useful if your pots sit against a wall, railing, or front door area where light comes mostly from one direction. Even exposure encourages more uniform bud development, so when bloom time hits, the whole plant looks covered instead of sparse on the back side.
10. Protect buds from extreme late-summer heat stress
Mums love sun, but prolonged stretches of brutal heat can still stress them, especially in black nursery pots or on west-facing concrete where the root zone bakes in the afternoon. I’ve measured the side of a dark plastic pot on a hot August day and it felt practically scorching. In those conditions, buds can stall and foliage can wilt hard by 4 p.m.
If you’re in the middle of a heat wave with highs over 90 degrees for several days, move potted mums where they still get at least 6 hours of sun but have a little relief from the harshest late-day reflected heat. Morning sun and bright midday light are ideal. You can also tuck nursery pots inside larger decorative planters to insulate the root zone a bit. For in-ground mums, steady moisture and mulch are your best heat defense.
11. Don’t crowd them with other fall decor too early
I know the temptation. The second stores put out pumpkins, cornstalks, and cute porch signs, I want my front steps to look like a magazine. But if you pack mums too tightly between decor pieces in August, you reduce airflow and make watering harder. That can lead to mildew, uneven light, and plants that stay damp in the wrong places.
I leave at least 4 to 6 inches between medium porch mums and any solid object, and more if the plants are large. This gives them room to breathe and keeps me from forgetting to check the backside of the pot for dryness or pests. Once the weather cools and blooming starts in earnest, you can tighten up the display a little if needed.
12. Plan now for longer-lasting color in September and October
If your goal is “exploding” fall color, timing matters almost as much as care. I like to have mums at slightly different stages in August if I’m decorating a porch or front bed. One plant may show color just starting to crack, another may be tight with buds, and another may be a week or two from opening. That way, everything doesn’t peak and fade at once.
When buying mums in August, choose plants with lots of buds and only a few open flowers if you want the longest display. A fully blooming mum looks amazing the day you bring it home, but it usually won’t last nearly as long as a bud-heavy plant. I learned this after splurging on big, gorgeous bronze mums one year for a family gathering, only to have them look tired way before my neighbors’ barely-open plants even got started.
If you already have established garden mums, think ahead about where the color will show best once bloom time arrives. Sometimes I move a container in late August from the back patio to the front walk because that’s where I’ll actually enjoy it every day during the busy fall stretch.
13. Know the difference between florist mums and hardy garden mums
This one saves a lot of frustration. Not all mums are meant for the same purpose. Hardy garden mums are bred for outdoor beds and seasonal toughness, while florist mums are often grown more for short-term display. Both can be beautiful in fall containers, but if you expect a florist mum to overwinter in a cold Zone 5 or Zone 6 winter after a rough late-season planting, you may be disappointed.
In August, I like to check the plant tag if I still have it. If I’m caring for mums in the ground and hoping they return next year, I make sure they’re hardy garden mums and keep them evenly watered so they can establish stronger roots before cold weather. If they’re decorative potted mums for a porch display, I focus more on immediate bloom performance and less on long-term survival.
14. Be patient once buds appear
Once you see lots of buds, the hardest part is honestly just not messing with the plant too much. This is where I’ve gotten impatient in the past and overcorrected. Too much fertilizer, random trimming, moving the pot three times in a week, or letting it dry out badly between waterings can all interrupt the momentum the plant has finally built.
At the bud stage, my routine gets very simple: check moisture daily, keep the plant in strong sun, remove anything obviously dead, and leave the buds alone. Within a couple of weeks, those tight green knobs start showing color, and then suddenly the whole plant changes fast. It’s one of my favorite garden moments every year because it feels like summer quietly handing things over to fall.