Why Are My Hostas Turning Brown? [Causes & Fixes]

Hostas in an outdoor garden on indoor pots suffer a few problems, and browning leaf edges should be a concern. Early and correct diagnosis of what’s troubling your hostas plants is essential to decide the next steps. What are the reasons for your hostas turning brown?

Your hostas turn brown because of drought stress, seasonal changes, and sometimes due to pests and diseases. Hostas plants thrive in evenly moist soils, so a drop in soil moisture will cause the leaves to droop and wilt before browning. Brown leaves also point to underwatering.

Hostas are a great addition to your house or garden, and you need to ensure they keep healthy and abundant. If you wish to discover why your hostas are turning brown and how to fix the problem, please read on!

Why Is My Hosta Leaves Turning Brown?

Hostas plants are winter-hardy, and their leaves and flowers come with a stunning visual appeal. Like other plants, hostas also develop problems and need good caring. And brown spots on their leaves point to environmental or pathogen-related issues that require swift action.

Hostas leaves turn brown because of insufficient soil water and extreme heat or direct sunlight. Hostas plant varieties with thin leaves and white-colored foliage are likely to burn when you expose them to direct sunlight. Although, pests and diseases could also be to blame.

Hosta Leaves Turning Brown: Reasons

Drought Stress

A drop in soil water content triggers plants to initiate several physiological and biochemical actions that differ from plant species. Drooping leaves is the most common and readily seen response.

Plants droop their leaves to reduce transpiration loss by altering stomatal distribution. A further drop in soil moisture content causes them to begin rolling their leaves, and eventually, the leaves’ edges turn brown.

The amount of water you give your hostas plants varies depending on weather conditions and the season. Their watering schedule for winter isn’t the same as for summer.

Hostas watering needs to peak at the height of summer and begin to wane as temperature drops before going to dormancy in the fall.

How To Fix It

Adequately Watering your plants will help them grow fast and remain healthy. Although hostas require well-drained soils, moisture content should always remain constant. Like most perennials, hostas plants require deep watering, but there’s a threshold.

They require about an inch (25mm) of water weekly. Therefore, you’ll need to establish a watering schedule to meet this threshold. You can achieve this by using drip irrigation systems.

To water your garden, you can buy this CARPATHIAN Drip Irrigation Kit (available on Amazon.com). It has adjustable water emitters to help you avoid underwatering or overwatering your plants.

However, you need to check your soil’s drainage and the weather. If you notice your hostas’ leaves drooping even after watering them with the required amount of water, you may need to adjust the amount upwards or water them more often.

Water your plants early in the morning. A morning watering schedule will give them sufficient time to take up the required water amount before the hot afternoon causes excessive evaporation. You might need to apply more water if your soil drains too quickly or improve it with organic material.

Petiole Rot

Sclerotium rolfsii var. fungus is responsible for causing petiole rot in hostas plants. It’s prevalent in hot and wet weather.

The fungus causes hostas plants to develop mushy brown spots around the petioles, where their leaves join the stems. As the infection takes hold, the leaves’ edges begin yellowing and eventually turn brown.

Heavy mulching around the plant’s crown is to blame for causing this fungus infection. Therefore, it would help if you kept a keen eye on your mulching styles. Don’t let the mulching material rest too close against your hostas’ plants.

How To Fix It

Dealing with petiole rot is quite demanding once it sets in. Here’s how you handle petiole rot-infected hostas:

  1. Remove all the affected plants and destroy them away from your garden. Avoid planting any more hostas in the affected areas for about three years.
  2. Disinfect all tools you used to handle infected plants with a mixture of one part of bleach to nine water parts.

Botrytis and Anthracnose Fungal Infections

Cool and damp spring weather conditions are conducive to several fungal infections. The common ones affecting hostas plants are botrytis and anthracnose. However, botrytis tends to be more prevalent in hostas plants during cool and wet weather.

Botrytis fungal infection on hostas manifests on the leaves as small water-soaked spots that eventually grow big. As the spots expand, you can see cinnamon to dark rigs forming on the lesions. These lesions can then move down to the petioles.

Anthracnose fungal infection also affects hostas plants during warm and wet weather. The disease manifests as extensive irregularly shaped brown spots on the leaves. It’s common for the spots’ centers to fall out, causing the leaves to have a tattered appearance.

How To Fix It

These practices will help you deal with fungal infections on your hostas’ plants.

  1. Apply water at the bases of the plants and not on the leaves. Apply water early in the morning to give the leaves enough time to dry: Leaves remaining wet for extended periods facilitate the spreading of fungal spores.
  2. Thin-out plants packed or growing too close together. This spacing will enhance adequate air circulation within the garden.
  3. Remove and destroy infected plants to avoid inoculum. Incolum is a live organism, such as fungi that may harm your hostas.
  4. Disinfect tools you used to prune infected leaves with rubbing alcohol. This sanitization will prevent the infection from spreading to healthy plants.
  5. Apply the fungicidal treatment to healthy plants. Fungicides help healthy plants resist contamination from infected plants.

Root Root

Root rot is another fungal infection that troubles plants in overly wet soils. Waterlogged grounds suffocate the roots, exposing the plant’s crown to rot risk. The plant’s foliage begins to brown and die along the margins.

How To Fix It

  • Remove any mulch on the waterlogged ground to allow for adequate evaporation.
  • Hold back watering until all the excess ground water evaporates.
  • If the plants come back to life, prune all their damaged leaves and parts to improve their appearance.
  • Look and fix any overflowing gutters and leaking pipes near your garden. They may be responsible for waterlogging your hostas.

Winter Dieback

Hostas plants begin to turn yellow and eventually brown in the fall and into winter. However, it’s not that they die in winter but enter into winter dieback, also called dormancy.

How To Fix It

There is nothing much you can do with your plants going through a natural process, but you need to know how to care for hostas during winter.

  • Prune all the leaves after their margins begin yellowing or browning.
  • Collect all the foliage on the plants’ bases and compost it.
  • Hostas don’t require wearing when they’re dormant.
  • Replenish the mulch at the base of the plant to about 2 inches (50mm) to protect the roots from frost damage and avoid covering the plant’s crown.

Excessive Sunshine

Hostas thrive in the USDA Plant Hardiness Zones 3 to 8, with some of its varieties doing well in Zone 9. This zoning means the plants can grow well in most areas of the US. However, they need a cold and wet season, eliminating some hot desert areas of the US like Morfa, Amarillo, and Utah.

Most hostas’ plant varieties aren’t tolerant of excessive heat and sunshine. They’re shade-loving instead. They thrive well under the soft morning sunshine and good shade from the blistering afternoon sun. Therefore, the browning of your hostas plants could result from excessive direct sunlight.

How To Fix It

  • Dig up garden plants and move them to a more shaded area.
  • Relocate indoor plants to a window that doesn’t receive direct afternoon sunshine.
  • Try to form a shade over your garden plants if the growing season is almost over, and wait until spring to relocate them before the growing season arrives.

Slugs and Snail

Most insects don’t cause the hosta’s leaves to turn brown, but slugs and snails do. These two feed on the hostas’ leaves’ edges, leaving them rugged and eventually turning brown. They can also puncture holes in the leaves’ middle parts, causing them to be brown from the inside out.

How To Fix It

  1. Apply slug bait on the topsoil around your hosta plant garden.
  2. Reapply the slug bait weekly and after a heavy downpour.
  3. Prune excessively rugged leaves, and leave those with minor damage as this will help to enhance the pants’ appearance.

Frost Damage

If your hostas show brown hostas leaves in late spring, it may indicate that your plants are experiencing frost damage. Hostas begin to recover from winter dieback in spring when the temperatures may still be low.

How To Fix It

  • Unless the whole plant suffers from frost damage, it’ll probably recover.
  • Cover your garden on chilly evenings until the danger of frost damage subsides.

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Final Thoughts

Hostas plants are beautiful plants that tolerate several weather conditions. But as you’d expect with any plant, bad moments come and may begin turning brown. It could be a natural winter dieback or a sign of something more sinister.

Overwatering and underwatering can stress your hosta’s plants, causing them to appear unhealthy. Keep an eye on your watering pattern to avoid water logging or exposing them to moisture stress.

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