Why Are My Hostas Not Growing? Unraveling the Mystery

Hostas are a favorite shade perennial in many gardens around the world. They can anchor a garden with their large mounds of foliage in various shades of green. They don’t spread or wander. Hostas are low maintenance. There are so many different varieties that you can plant a variety of hosta in almost any space.

But of course, like every living thing, hostas aren’t without their problems. From leaf curl, to yellowing and browning leaves, these plants aren’t immune to a number of different issues. However, with a little planning and forethought, you can prevent or eliminate most of them.

If you are having issues with your hostas, this comprehensive list of common hosta problems can help you identify and resolve any issues you may have. With a little bit of care, you’ll have your hostas back to green & pristine condition in no time. Ready to learn more? Let’s dig in!

Yellowing leaves in a hosta can be caused by a variety of things. But the first thing to check is the soil. Wet heavy clay soil that cannot properly drain could be the problem. Hostas like light free draining soil best.

Do a quick test on your soil by grabbing a handful of it. Squeeze it together in your hands and release it. It should just crumble away in your hand. If it stays in the shape of the ball like putty, it is too heavy. Use coconut coir or peat to break up the heavy soil. You can work it in around the base of the hostas.

If you checked the soil and it doesn’t seem too heavy, perhaps it is a watering problem. Do not over water your hostas. Especially if they are in more shade. This will cause the leaves to turn yellow and eventually could lead to stem and crown rot. Another sign could be petiole rot, which I will address below (#10).

Leaves Covered in White Powder

You can get rid of powdery mildew with a fungicidal spray.

Powdery mildew is a fungus that covers the leaves of plants in a powdery film. Take your finger and run it along the leaf. If the powder comes off, it’s powdery mildew.

Prevention is definitely the way to go with powdery mildew. Make sure the hosta is in enough light that its leaves can dry out completely between watering. Water without spraying the foliage (drip hoses are great).

Make sure it is in nice light free draining soil. Also make sure there is a bit of space between your hostas and other hostas or plants so that there is adequate airflow.

Of course, this bit on prevention must be thoroughly annoying if you already have powdery mildew and just want to get rid of it. Not to worry, there are products on the market to deal with mildew. A fungicide spray purchased from a garden center works great. Make sure it includes powdery mildew on the label. Use according to package directions.

The most common hosta pests are slugs and snails, which feed on hosta leaves and make holes in them.

Leaves chewed full of holes are usually caused by hosta’s nemesis, snails and slugs. Hostas thrive in damp and shady conditions. So do slugs and snails. There is also not much you can do about a period of damp and rainy conditions.

There are many methods for ridding snails from your garden. There is the very popular saucer full of beer method. Where you put a tray if beer out and it lures them in and you toss them out. This needs to be closely monitored to be effective.

Putting rings of crushed egg shell around the plants works as well. It cuts their soft sluggy bodies. But it will need to be reapplied throughout the season. You can also try and plant the thicker leaved hostas, like ‘Blue Angel’s or ‘Brother Stefan’.

Slugs and snails don’t chew those thicker leafed hostas as easily. Although, if there’s no other options, they will munch them.

My favorite method for ridding snails and slugs is snail bait. I purchase a bag of small cylindrical pellets from my garden center and I sprinkle it through the garden. The slugs disappear. Apparently they eat it and hide to die. But there are no slug corpses lying about and my hostas remain slug free.

Deer and rabbits are other hosta pests that feed on leaves and stems.

This is a big one. Hostas are a salad bar for rabbits and deer. If all you have left of your hostas are eaten stems, they are probably being eaten.

Rabbits and deer love munching on hostas, there is no doubt about that. There are a few things you can do to try and save them.

There are animal deterrent sprays you can purchase from the garden center. Spray the foliage of your hostas with is and animals should avoid it. You will need to reapply any time it rains or you do any overhead watering.

Fences are effective, albeit expensive. But creating a fenced in garden will deter deer, and maybe rabbits depending how tight the fence is.

However, if this becomes an ongoing problem and frustration, it might be time to replace your hostas with something animal resistant. Rhubarb has the big hosta leaf feel, but deer don’t munch its toxic leaves. Or bergenia has waxy leaves that look great in the shade. They will eat the flowers off them but leave the leaves behind.

To get rid of aphids, you need to spray the host with insecticidal soap.

Sticky leaves on a hosta could be from a couple of different pests.

Aphids secrete a sticky sap. While they probably won’t kill your hosta, they are unsightly and can lead to other diseases and pests attacking.

Aphids usually attack a plant that is weak. So after you deal with the infestation, try your best to identify and correct the environmental problem (lack of water, heavy soil etc). I find aphids often appear on the stems of the flowers of hostas. I will just prune those off. Then I will spray the hosta with an insecticidal soap. Repeat weekly as needed.

Mealybugs also leave a sticky substance known as honeydew. Black mold can begin to grow as a result of this sticky substance. So it’s best to control this infestation quickly. Mealybugs can be difficult to control.

If there aren’t too many on the plant spray then off or dab them with a cotton swab dipped in rubbing alcohol. If it is a larger infestation go straight to the insecticidal soap. Keep treating weekly until the infestation is gone.

Hosta Virus X has symptoms such as spots, wrinkling, and leaf necrosis.

Mottled leaves are bad one for hostas. If your hosta leaves are taking on a mottled appearance you may haveHosta Virus X. Mottled leaves are the main symptom to notice. But also Puckered leaves and necrosis of the leaves can happen along with the mottled appearance.

Do not prune out these discolored leaves. This will only spread the virus further. Unfortunately there is no treatment for the virus. The plant should be dug up and disposed of as soon as the virus is identified. Do not let it spread to your other hostas.

Since there is no treatment for this disease, be sure to check over plants purchased from a garden center or nursery carefully. Choose healthy plants with evenly colored foliage. Also, check over plants received from garden trades or neighbors. Lots of diseases, weeds, and pests are spread by well-meaning gardeners.

Wrinkled leaves are not necessarily a sign of disease, it could just be a type of hosta.

While puckered leaves along with other symptoms can be a sign of a more serious problem (hosta virus X), Puckered leaves on their own may not be a problem at all. This is why it is important to really check and rule out disease before ripping out your hostas.

There are many, many varieties of hostas. I know sometimes when we purchase them from the garden center they don’t always say the exact variety on the tag. Sometimes it just says Hosta Spp. I like to try and figure out the variety.

Some varieties have thick corrugated leaves. ‘Brother Stefan’ hosta, for example, has thick corrugated leaves that can appear puckered. They look even more puckered when the new leaves are unfurling. This is normal.

There is another reason for puckering hostas. Some of the hostas with various shades of green in them can be affected by what is known as the drawstring effect. This occurs in varieties that have a light colored margins and darker centers (eg. Hosta ‘Brim Cup’).

This occurs because the inner portion of the hosta has more chlorophyll and produces energy faster than the colorless white margin, so the inner leaf is growing fast and will push the edges up resulting in a cupping effect.

The only thing to be done about this is to purchase hostas that are a single color or have thinner leaves. Or try planting your puckered leaf hosta in an area with less light to slow the growth of the plant down and hopefully avoid the puckering.

Large Irregular Spots on the Leaves

Fungal disease Anthracnose infects the hosts forming large spots on the leaves.

Large, regular spots that are surrounded by dark borders is the tell tale sign of anthracnose. Anthracnose is a fungal disease that affects hostas. While it normally isn’t fatal, it ruins the most important aspect of a hosta, they’re beautiful ornamental foliage.

Prevention is key for this one. Avoid getting the leaves wet on a hosta. I know this isn’t possible entirely because, well, it rains. But there are times when spraying the leaves is avoidable.

I water my hostas by using a drip hose that snakes through the garden bed. I turn it on for a few hours a week and it waters the soil directly. If you are using an overhead sprinkler, water in the early morning. This allows the sun to dry off the leaves quickly. If you water at night, the leaves sit wet all night long and give the fungus a chance to settle.

You can simply snip off any leaves affected by the fungus and let new leaves grow in. You can also apply a fungicide that contains chlorothalonil.

My Hostas Are Not Growing