What Your Lavender Needs in August – These 5 Easy Tasks Keep Your Plants Lush and Multiply Your Blooms

Lavender is a staple in my garden, and its bright purple flowers and fragrant foliage are a source of ongoing joy. However, this month, lavender plants are likely transitioning from peak bloom to seed set. But that doesn’t mean you need to take a step back and leave these gorgeous perennials to it. This is an ideal window in which to prevent your plants from getting too leggy or woody, and lay the foundations for an even more fragrant, abundant display next year.

Although lavender thrives in full sun, the heat of late summer can cause the plants to struggle unless you care for them properly. Turn a blind eye to their needs now, and there is a chance woody lower stems could harden without producing replacement growth, leading to unsightly, splitting centers by next spring. However, as anyone who grows lavender will know, excess moisture and humidity can also challenge your plants. So you’ve got to take the weather into account, as well as variety.

These easy August care steps will help you prevent the dreaded leggy burnout, while also ensuring your lavender doesn’t become vulnerable to late summer rots. A few moments of the right care right now can also set you up for extra flowering and fragrance next time. So don't let your lavender go leggy as summer wanes. These quick August tasks will protect silver foliage, prevent root rot, and set you up for more lush, heavily scented blooms when the warm weather returns next year.

Key Lavender Tasks in August

If you’ve grown lavender for a while, you know not all species have the same growth cycle. Some rebloom in fall under the right circumstances, but many do not. And of course, not all regions have the same summer weather, which has some bearing on the tasks below. That said, most lavender types like heat and minimal water. This means cool or wet summers can be a challenge. To keep things interesting, too much heat and drought can also be a problem. English lavenders (Lavandula angustifolia) can struggle with excessive humidity, while Spanish types thrive in warmer zones but have a shorter lifespan.

Before picking up your shears, keep species type in mind, as well as microclimate, and whether they are growing in open soil or containers. English lavender, French and Spanish lavender (L. stoechas), and hybrid lavandins (L. x intermedia) behave differently in late summer. English types are cold-hardy (in USDA hardiness zones 5-8) and appreciate some late-August shaping, while tender Spanish types (zones 7-10) can react poorly to aggressive late-season pruning in wet or humid regions.

Container-grown lavender love requires extra care this month. While ground plants can send roots deep to escape surface drought, potted lavender doesn’t have the same options. Container walls absorb high heat, and in humid regions, stagnant air around dense foliage can trap moisture, creating ideal conditions for root rot.

It’s a good idea to check moisture levels at the root level with a moisture reader like the XLUX Soil Moisture Meter, available on Amazon. If your potting soil has become compacted, it’s also wise to add some gritty Back to the Roots Organic Succulent and Cacti Mix, available from Walmart, with ingredients like perlite and dolomitic limestone, which is great for drainage. This will help set you up for the tasks below.

1. Deadhead Faded Flower Spikes

Generally, French lavender is a long-blooming variety with flowers from spring through fall in frost-free regions. But some English cultivars (like Gros Bleu and Buena Vista) can bloom a second time in early fall if you deadhead the faded flower spikes in August. So, if you have one of these cultivars, deadheading faded flowers toward summer’s end can prompt fresh growth. However, if your area gets early fall frosts, hold off. New growth can get damaged by an unexpected frost.

Mid-August is basically the deadline to trim off your spent flower spikes before they turn brown and seed out. But it is hugely dependent on your lavender variety, as well as your local climate and anticipated fall frost arrival. If you do deadhead, snip spent flower stalks at the point where they emerge from soft fresh foliage. To harvest long, fragrant stems without tearing tender plant tissue, use sharp pruners such as Fiskars Micro-Tip Pruning Snips with Softgrip Handles, available at The Home Depot.

This is a lovely opportunity to harvest spikes for drying, sachets, or culinary use. Gather your stems in a tightly woven basket, like the Hittomen Handmade Rattan Bread Baskets from Amazon, which are a nice shape and hold plenty of blooms. You can expect to see fresh aromatic growth within 10-14 days of deadheading.

2. Clear Debris and Refresh Grit Mulch

Clean-up is beneficial for all plants and can particularly help lavender. So remove the dead leaves and pull out the debris from the entire area. This will improve the airflow around the lavender, and will also reduce the number of pests that like to live there. To clear out dead foliage and debris trapped inside dense branch joints, clear the base using durable protective wear like Wells Lamont Cowhide Leather Work Gloves from Amazon, which balance a good fit with robust texture.

A plant like lavender needs extra help in a humid climate to guard against rot and moisture damage. You can reduce the chances now by clearing away any mulch near the plant. Remember that mulch holds moisture in the soil, and that is the opposite of what your lavender needs at the moment. Other perennials may thrive under damp, wood-chip mulches, but lavender reacts poorly to trapped humidity.

Replace any damp wood mulch near your lavender with a 2-inch (5cm) layer of crushed pea gravel, coarse grit, or horticultural sand, scattered around the base. A clean, reflective mineral layer, such as Vigoro Mini Marble Chip from The Home Depot, can help to reflect heat back up into the lower lavender canopy, keeping root crowns dry and preventing soil splashback. Trimming nearby weeds also helps.

3. Master Midsummer Hydration

Giving your lavender the right water this month is a little tricky. It has adapted to dry conditions and is drought-tolerant. But it still needs some water, especially in very hot phases. If your climate is hot and dry in August, set up a once-weekly irrigation schedule. Water at the base, and allow soil to dry thoroughly before the next session. But if you live in a climate that gets lots of rain in August, you don’t need to (please read this as shouldn’t) provide any extra water. Too much makes a lavender unhappy and can result in loss of your plant.

Young, newly planted lavenders require regular watering during their first summer to establish a deep root system. By contrast, mature plants have deep taproots that cope better in dry conditions. Frequent, shallow surface watering encourages weak, surface-level roots and keeps the upper root crown damp, leading to fungal dieback. So when you do water, water deeply, and definitely not daily. Don't spray water overhead onto silver foliage during peak afternoon sun, as wet foliage combined with high heat causes leaf scorch and humidity rot.

To deliver water directly to the places that need it, stick with a ground-level watering vessel like the Yowon Gold Long Spout Watering Can from Amazon, which has a low angle of watering. If container plants suffer from hydrophobic, dried-out soil, soak the base in a shallow tray to allow slow absorption but reduce the risk of rots.

4. Give Plants a Late Summer Shaping

For species and cultivars that won’t rebloom, August is a good time to prune your lavender, but time is of the essence. Wait until all of the blooms have faded, so plants have the chance to complete their full flowering cycle. When you prune, think in terms of a dome shape. Trimming into a dome shape will promote healthy growth. Snip back leggy stems above leaf sets, and prune back about a third of the canopy (around 8 inches or 20cm) into a neat shape. Never cut into older wood, since most old wood will not regrow. You are safe if you see green leaves below the cut.

When shaping large, established lavender shrubs quickly and evenly, use lightweight hedge shears like the Corona ClassicCUT Hedge Shears from The Home Depot, which have nice contoured handles for good grip and comfort. For precision hand-shaping on more compact varieties, use the exceptional Fiskars Bypass Pruners from Amazon, which offer lifelong precision cutting. Proper shaping yields a compact, silver-green evergreen mound that retains its structure through winter.

French and Spanish lavenders need a different approach. These are identifiable by their tufted flower spikes. They flower in late spring in warmer zones and early summer in colder zones, and can keep blooming into fall. However, they are less hardy than English lavenders and you need to be gentle. They need a light foliage trim only, as heavy pruning leaves them vulnerable to winter cold. Limit your snipping to frequent deadheading and lightly shaping after individual flush cycles.

5. Propagate Semi-Ripe Cuttings

Late August presents an ideal window for taking semi-ripe cuttings from healthy lavender bushes. Take these semi-ripe cuttings from this year’s growth, where the stem base is firm and woody, but the tip remains flexible and green. Rooting cuttings from your favorite cultivars allows you to create duplicate plants for garden borders or container displays next spring without spending a dime. This is one of the loveliest lavender tasks to do in August to boost next year’s blooms.

Take 3-4-inch (8-10cm) side shoots from non-flowering stems for the highest rooting success rate. Heel off side shoots by gently pulling them downward off the main stem so a small piece of bark (the heel) remains attached. Strip the lower leaves off the bottom 1.5 inches (4cm) of the cutting to expose the leaf nodes, which are rich in rooting hormones. You can stimulate root development if you dip cuttings in Garden Safe TakeRoot Rooting Hormone, available from Walmart, which is very reliable.

Insert your prepared cuttings into a gritty, free-draining propagation mix. If yours feels a little on the squidgy side, then add some perlite, like Sta-Green Organic Perlite from Lowe’s, or some coarse sand. Cuttings should form strong root systems within 4-6 weeks, ready to overwinter in a protected frame or cold greenhouse. Keep them shaded, and maintain light moisture. Don't take cuttings from heavily flowered stems, as they will lack the energy needed to form new root systems.

Shop Lavender Care Essentials

Maintaining a neat, fragrant, and heavy-blooming lavender patch comes down to patience, observation, and a few targeted tools, high-drainage amendments, and protective extras. These care tips will stand you in good stead, but make sure you have the best kit to hand. Here are a few high-impact essentials for late-summer lavender care.

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