Can I Revive My Brown Hydrangea? Essential Steps to Save Your Heat-Stressed Shrub in August

Late summer can be a tough time for many garden plants, but hydrangeas are having a particularly rough time this year. With such hot August temperatures and many areas in drought, it would be surprising if you’re not seeing signs of seasonal distress with a noticeably brown hydrangea. Browning flowers or crisp leaves don’t automatically mean your shrub is dead or past saving, and there are many reasons why hydrangeas turn brown in August. But because of this year's extreme El Niño summer, how you deal with these symptoms is critical to whether or not your shrub recovers, and how well.

For a start, don't panic if your hydrangea droops dramatically in the heat of the afternoon, especially if it's also getting sun late in the day. This is a normal response as the plant is transpiring (losing) water through its leaves faster than the roots can pull water up through the soil. Once the sun goes down and temperatures drop a little, you should see the plant perk up again.

While drooping is normal, it's essential to take heed of this warning sign and keep a close eye on your plant. If its response progresses to browning flowers or leaves, your hydrangea is undergoing more significant stress and it’s time to act. With a careful diagnosis and a plan of attack, as well as essential hydrangea care in August, you can stop the damage from spreading and protect healthy growth so the plant can recover. Find your specific symptoms below to discover exactly what to do next, and hopefully save your brown hydrangea this heatwave summer.

STAGE#1 My Hydrangea Flowers Are Starting to Turn Brown

Flower browning isn’t necessarily an issue. For many hydrangeas, this is a natural transition as flowers fade and, because of the hot and dry weather, that may be happening earlier than usual this summer. If yours is a bigleaf hydrangea, it's good to know that Hydrangea macrophylla is more prone to flower wilting and premature browning than other types.

However, normal browning occurs slowly. If flowers brown more suddenly during hot and dry conditions, and you spot other distress signs like wilted leaves, that's due to water or heat stress, or blooms being scorched by the sun.

If your hydrangea is showing signs of premature stress-browning on the flowers, check the soil first. Push your finger several inches into the ground or use a moisture meter like this Long-Probe Soil Moisture Meter from Walmart. If the soil is dry below the surface, your plant needs more water. The solution is to give it a deep soak at the soil level, as opposed to a light or overhead sprinkling.

Use a soaker hose like this Element Rubber Soaker Hose from Lowe's or just hold a regular hose nozzle at the base of the plant with the faucet turned half-on. Slower and longer is better to let the water penetrate deeply into the soil. Move the hose outward as you go, ensuring you soak the soil all around the drip line (the soil beneath the outer rim of the shrub, where rain shed from the shrub would fall most heavily) as roots will be concentrated here, rather than by the main stem. If your hydrangea is potted, soak the soil well and repeat as soon as the soil dries again, which might be daily during a heat spell.

Reinvigorating tired, heat-stressed plants with a seaweed tonic in August will also help, as it stimulates roots to take up more nutrients and moisture from the soil.

You can also help revive your plant by providing some protection from heat and sun in the afternoon. Move potted plants into a shaded spot. For in-ground shrubs, rig up a garden shade cloth such as this from Amazon, or even a patio umbrella, to create temporary shade. Laying a 2-3 inch layer of natural mulch such as Miracle-Gro Organic Mulch from Walmart will also help keep water in the soil and roots cool, but keep it away from the main stem to prevent rot.

STAGE#2 My Hydrangea Flowers Are Totally Brown

Again, brown hydrangea flowers is a situation with two possibilities: either the flowers have naturally reached the end of their lives and your hydrangea has done blooming, or they're browning prematurely due to seasonal stress. To tell the difference, look at the rest of the plant. Is it healthy and vigorous or wilting and turning brown elsewhere?

If the plant looks stressed in addition to having brown flowers, it needs some attention to revive it, so follow the Stage #1 steps of watering, shading and mulching, plus the relevant advice for further stages if needs be.

Whether flowers have turned completely brown because the plant is stressed or the shrub is simply done blooming, it's best to remove them. Use a clean pair of hand pruners such as these Fiskars Steel-Blade Pruners from Walmart. Do make sure blades are sharp – healing crushed, ragged cuts will place unnecessary stress on the plant, and sharpening pruners is a two-minute task with a tool like this $7 Garden Guru blade sharpener from Amazon. For bigleaf hydrangeas which bloom on old wood, make the cut just below the base of the faded flower, as cutting off too much growth in August will compromise next year’s blooms. For panicle and smooth hydrangeas that bloom on new wood, cut back to the first healthy set of leaves.

STAGE#3 My Hydrangea Leaves Are Turning Brown at the Edges

Brown, crispy edges on otherwise green leaves, brown tips to green leaves, and dry, curling brown areas on leaves are all signs of heat and drought stress on hydrangeas. Other big clues that this browning is due to seasonal stress is if it's occurred during or just after a heatwave or drought, and if the soil is dry when you test it with your finger or a moisture meter.

To revive your hydrangea at this stage, start with a deep soak of the plant’s roots, both for potted and in-ground plants, following the steps for Stage #1. Repeat as needed, which means checking the soil moisture daily, especially for potted plants. It’s better to water deeply and less frequently than to water daily and only lightly, but container plants often need daily deep soakings, especially in hot weather, so be guided by your moisture meter.

Follow the Stage #1 steps for mulching and shading, too.

Resist the urge to remove all the leaves with brown edges or tips and tidy up your plant. If most of a leaf is green, it’s still conducting photosynthesis and is useful to the plant’s recovery.

STAGE#4 My Hydrangea Leaves Are Totally Brown and Dropping

If the damage has progressed to completely brown hydrangea leaves that are dropping from the shrub, the cause may be severe heat and drought stress or it can indicate standing water at the roots or a disease. Here’s how to tell what's troubling your hydrangea.

Leaves that are dry, crispy and brown typically indicate heat and drought stress. If there's still some healthy growth on your plant, the heat and drought stress can be reversed. Water, mulch and shade as outlined in Stage #1, and use your moisture meter to decide how regularly the plant needs watering. Remove any leaves that are totally brown and dead. Don't fertilize, as feeding a severely stressed plant can cause more damage.

Leaves that are softer and yellowish rather than brown are likely caused by too much moisture. Check the soil with your moisture meter to confirm and, if you believe the issue is due to too much water, stop watering immediately and let the soil dry out. If the hydrangea doesn't show any signs of recovery, you probably have a drainage issue. Dig the plant up and trim off any rotting, mushy roots, and improve soil drainage by adding sand or compost before replanting, or move to a spot with faster-draining soil.

If you're growing a hydrangea in a container, check there is a drainage hole and that it isn't blocked. Raising the pot on risers such as these Invisible Pot Feet from Amazon will improve drainage, or you may need to repot your hydrangea. Using a moisture-control mix such as Miracle-Gro Moisture Control Potting Mix from Walmart will help regulate water levels.

Leaves that have browned as spots joined into patches indicates disease. Move onto Stage #5, pronto!

STAGE#5 My Hydrangea Leaves Have Brown Spots

Browning due to heat and drought stress tends to start at the edges and move inward. If the browning begins with spots on hydrangea leaves, your plant may be diseased. Some of the typical patterns of disease on hydrangea leaves include:

• Small brown or tan spots
• Spots that have dark edges
• Multiple spots that merge into larger discolored areas
• More spots on older leaves

If you suspect disease rather than seasonal weather stress, start by removing damaged leaves and cleaning up any that have fallen to the ground, wearing rubber-coated gloves such as these from Amazon. Fungal spores can transfer from infected leaves to healthy foliage so dip pruner blades into isopropyl alcohol such as this from Amazon to disinfect between cuts. Rake up any dropped leaves, too; a shrub rake such as this from Lowe's makes the job easier. Dispose of all this plant material in the garbage, and don't add it to a compost pile.

Next, change your watering practices, avoiding overhead watering and irrigating shrubs at their base so you don’t get the leaves wet, as damp foliage welcomes disease. Water in the morning so any splashes dry quickly. Improving airflow helps make conditions less conducive to disease, too, so if your hydrangea seems crowded, trim out some stems to allow more air movement.

Take some photos, too. Then, if your hydrangea doesn't recover after these measures, check with your local nursery or extension office to diagnose the exact disease and find a treatment. You can still likely save hydrangea shrubs if you act quickly and use the correct product.

STAGE#6 Is My Hydrangea Dead?

None of the above measures will help if your hydrangea is already dead. However, don't presume that your shrub is entirely dead, but test whether individual stems are alive.

Use your fingernail or the edge of shears to lightly and gently scratch a small section of the outer layer of the stem. If you find green tissue underneath, it’s still alive. If it’s brown, the stem is dead – but work your way down the stem to see if you find any green, living tissue closer to the base. Prune any dead stems, either to the base of the plant if there are no signs or life, or back to where you find green tissue.

Follow the watering, mulching and shading steps for Stage #1 and, if there is sufficient life left in the main stems and the roots are healthy, your plant can recover, but it may take some time.

A brown hydrangea can be disheartening, but it doesn’t necessarily mean your hydrangea is lost. Take your time to diagnose the problem first, and then you can work on a solution to bring it back to life. With the right care, chances are your hydrangea will be back to full bloom next year.