Why Are My Hostas Dying? [Causes & How to Fix]

Hostas are one of the most popular perennials in the landscape, and for a good reason—they are easy to grow, shade tolerant, extremely hardy, and require little maintenance. So when your hostas start to die, it can be a real mystery. Is there something you’re doing wrong, or is it just something that happens?

Your Hostas are dying due to damage from pests, inadequate care, or disease. The leaves turn yellow, brown, or black and eventually die. Your hostas might also die when its growing season is over, and the plant goes dormant. This decline is normal; you can cut it back while preparing it for the next season.

Understanding why your hostas are dying is the first step in preventing it from happening again. Once you know what’s causing the problem, you can take steps to fix it. Read on as we explore why hostas die and how to prevent it.

Leading Causes of Hosta Plants Death

Hostas add beauty and interest to any landscape. Their heart-shaped leaves come in various colors that pique the interest of novice and experienced gardeners alike. Unfortunately, they turn even the most picturesque gardens into eyesores when they die.

There are several reasons why hostas might die, and understanding these causes is the first step in preventing them from happening again.

Pests May Kill Your Hosta Plants

Pests are a nuisance in any garden, but they can be especially damaging to hostas. These common pests attracted to the tender leaves will destroy your hostas if you leave them unchecked. Close monitoring of your plants should alert you to a pest’s presence and allow you time to act before they damage your plants irreparably.

The most common culprits you will find munching on your Hosta patch are as follows:

Slugs and snails feast on hostas. The moist soil and the plant’s tender leaves powerfully attract these slimy creatures. As they feed on the leaves, they perforate holes on them, reducing the plant’s ability to photosynthesize and eventually kill it. The leaves of infected plants will turn yellow and brown as the plant slowly dies.
Other pests that commonly attack hostas include caterpillars, aphids, and Japanese beetles. Aphids suck the sap from the leaves while caterpillars eat the leaves themselves. Japanese beetles are particularly destructive as they not only eat the leaves but also lay their eggs in the soil. The larvae then hatch and feed on the plant’s roots, ultimately killing it.
Deer and rabbits are also major pests of hostas. And while they typically don’t kill the plant outright, they will nibble on the leaves and stems, causing unsightly damage. Their constant grazing can also stunt the plant’s growth and prevent it from reaching its full potential.

How To Control Pests on Hosta Plants

Proper pest control is essential to keeping your hostas healthy and damage-free. Some require more effort than others, but all are necessary to maintain a pest-free garden. Here is a list of the best ways to tackle common pests in your hosta plants:

Slugs and Snails

The best way to control slugs and snails is to handpick them from the garden at night when they are most active. It’s best if you use a flashlight to find them hiding in the leaves. You can also set out traps baited with beer or put out a bowl of pet food to lure them in. Once they’re in the trap, dispose of them far away from your garden.

Diatomaceous earth is a natural way to control slugs and snails. It is made from fossilized diatoms and works by puncturing their bodies as they crawl over it. Alternatively, you can use coarse substances like sandpaper and crushed eggshells, providing a barrier they can’t cross.

Caterpillars and Japanese Bettles

You can control caterpillars and Japanese beetles with insecticidal soap or neem oil. These organic pesticides work by suffocating the insects and disrupting their life cycle.

For best results, apply them in the early morning or evening when the insects are less active. You will need to reapply these pesticides every few days to keep the pests at bay.

Aphids

You can use Ladybugs to naturally destroy these pests are the natural predator of plant aphids. Aphids are insidious plant killers that lurk hidden from notice until plant damage alerts you to their presence.

Ladybirds are a tremendous natural deterrent; you can purchase them online or at your local garden center. Once released into the garden, they feast on the aphids and help keep their population in check.

Deer and Rabbits

You can fence off your garden to keep deer and rabbits out. A simple wire fence will do the trick, or you can opt for a more permanent solution like a brick wall. You can also try using repellents to keep them away.

Repellents made with predator urine or capsaicin (the compound that makes chili peppers hot) are effective at deterring deer and rabbits.

Diseases May Be Behind Your Dying Hosta Plants

Like other plants, hostas are susceptible to diseases. When not properly cared for, they are more likely to succumb to diseases that can quickly kill them. Common diseases that infect hostas include:

Anthracnose

Caused by Colletotrichum, anthracnose is a fungal disease that affects plant leaves. Symptoms include large, irregular, or round tan spots with dark spots in the center. Control includes removing infected leaves, applying a fungicide, and keeping water off leaves when irrigating.

Fusarium Root and Crown Rot

Caused by the fungus Fusarium, this disease infects the roots and crown of the plant. Symptoms include wilting, yellowing, and the death of leaves. The stem experiences a brown-to-black decay at the soil line.

Remove infected plants to curb the spread of the disease, and be cautious when transplanting not to injure the stems or roots.

Bacterial Soft Rots

Pectobacterium is a bacteria that causes soft rots in hostas. These rots can affect the petioles and lower leaves, causing a smelly wet decay that turns the leaves yellow before wilting and collapsing.

Management involves removing and destroying infected leaves and plants. Clean and disinfect knives and tools after working in the affected area to prevent the spread of bacteria.

Petiole Rot

Petiole rot is caused by Sclerotium rolfsii, and you will notice your hostas leaf stems turning brown at the soil level; the leaves turn yellow and brown before wilting and eventually dying. You might also see white fan-like fungal growth at the plant’s base.

Remove the affected plants and dispose of them to prevent the spread of the disease. You should also avoid piling too much mulch or soil at the plant’s base, as this can create an ideal environment for the fungus to thrive.

Root-Knot Nematode

Meloidogyne spp. is a type of nematode that feeds on the plant’s roots, causing galls or knots to form. These galls can stunt the plant’s growth, cause the leaves to turn yellow, and make the plant more susceptible to drought stress. Destroy the affected plants and avoid planting hostas in infested soil before solarizing or fumigating it.

Inadequate Care May Cause Hosta Plants To Die

Hostas prefer partial to full shade and moist, well-drained soil. They are relatively low-maintenance plants and only require occasional watering and fertilization. However, they need enough space to spread out and should be planted 20 to 80 inches (50.8-203.2 cm) apart, depending on the variety.

Hostas grow best in USDA hardiness zones 3-8, including states like Florida, South Dakota, Nebraska, and Wyoming.

While hostas are relatively low maintenance, they still need proper care to thrive. If you don’t provide them with the right conditions, they will slowly start to die. Some of the most common problems include:

Improper Moisture Levels

Hostas need moist, well-drained soil to survive. If the soil is too dry, the leaves will start to brown and curl. If it’s soggy, the roots will start rotting.

Avoid planting hostas in areas prone to flooding or that don’t drain well. Be sure to water them regularly, especially during dry periods, and avoid leaving water on their leaves.

Too Much Sun

While hostas prefer shady conditions, they also need some sunlight to grow. If they don’t get enough light, the leaves will pale, and the plant will become etiolated or stretched out.

The leaves will start to brown and curl if they get too much sun. Choose a location for your hostas that gets dappled sunlight or filtered shade.

Excessive Use of Fertilizer

Since hostas grow in zones 3-8, they don’t require too much fertilizer. Applying too much can burn the roots and damage the plant. You need to source a fertilizer specific to your hosta’s needs. Use a slow-release fertilizer or one specifically designed for shade-loving plants and follow the instructions on the package.

Accidental Damage

Hostas are tough plants, but they’re not indestructible. If you accidentally damage their roots or leaves, it can cause them to die. This problem is common when working with a lawnmower or weed whacker.

Be careful when operating these types of machinery near your hostas to avoid accidents. Any physical damage to the plant can also make it more susceptible to diseases and pests.

Final Thoughts

Hostas are an excellent addition to any garden. They’re easy to care for, tolerant of a wide range of conditions, and come in various colors and sizes. However, even the tough hosta can succumb to problems if they’re not correctly maintained.

Pests and diseases are the main culprits, but improper care can also be to blame. Too much exposure to the sun, improper moisture levels, and excessive fertilizer can all cause hostas to die. Carefully choose the location for your hostas and pay attention to their care needs to keep them healthy and happy.