by Erin Marissa Russell
Hostas do well in containers whether you want to grow the large specimens or dwarf plants. But there are a few best practices you can follow to get the best possible results out of your hostas when they’re growing in planters. Keep reading to find out more.
Situate Hostas in the Best Location for Their Preferences
Most plants will flourish if you find them a place in the garden that gets plenty of sunlight and provide them with a bit of water now and then. But hostas don’t quite fit this bill. As opposed to the other plants in your garden, hostas are shade-loving, moisture-loving plants. They need a location that suits their needs. Too much sunlight can scorch the foliage of hosta plants with sunscald and also result in their water evaporating too early. Hostas will never really thrive unless they’re provided with shade and moisture. The good news is, this means you can use hostas to fill those spots in your garden where nothing else will grow.
Choose the Right Container for Your Hosta
In most cases, you’ll want to choose your plant first and match your container to the plant’s needs as opposed to doing this the other way around and choosing a container first. Of course, if you just happen to have the perfect pot for your new hosta in your collection, it’s okay to go with it. But hostas have particular needs when it comes to keeping them happy in containers, and it’s important that you match the container to the plant according to the tips below.
Getting the right container is just an important consideration because ultimately, the size of your container will determine the maximum size your hosta can grow to reach. (As an aside, you should know that hostas growing in containers are somewhat limited in size. They’ll never reach the mature size of hostas growing directly in the ground.)
When you’re selecting the right container size for your hostas, bear in mind that these plants have roots that develop more horizontally than they do vertically. The root size will be about the same as the size of the plant that’s visible above the surface of the soil. Because hostas have root systems that are wider than they are long, you need to choose a container that is also wider than it is long—at minimum, one that has equal depth and width. The planter should also allow at least three inches between the base of the plant at the center of the container and the lip of the container at the edge.
If you decide to bypass this rule and go with a planter that’s taller than it is wide, the roots won’t be able to fill up the bottom of the container, so you’ll end up dividing or transplanting your hostas more frequently.
You can counteract this by filling the empty space in the bottom of the planter with an empty liter bottle. Use a whole, undamaged bottle, and keep the cap on so the bottle keeps its shape. Not only does this fight back against having to transplant or divide your hosta plant too often, it also reduces the weight in your container, making it more portable if you need to move it around during inclement weather or to change with the seasons in your garden.
The material is up to you, but there are a few material options you may wish to avoid that we’ll list here. Black containers and metal containers get too hot for shade-loving hostas. If your hostas will stay outdoors during the wintertime, you may wish to avoid clay or concrete planters. When they’re exposed to low temperatures, containers made of these materials can crack, leaving the hostas you’ve taken such good care of spilled out onto the ground. There are glazed pots that have guarantees not to crack for certain periods of time, or pressure-treated wood is durable and long-lasting. Other good options include fiberglass or recycled plastic containers, which have the bonus of being good for the environment.
All containers, not just those used for growing hostas, should come equipped with drainage holes. You may have heard some old wive’s tales about using rocks or broken pottery at the bottom of your containers. This won’t really do anything to improve the drainage of your planter. Make sure that the holes are large enough to provide sufficient water flow but not so large that the planting medium will flow out of them. Sufficient drainage is also an important part of ensuring that hostas don’t get root rot, which they can be susceptible to because of the moist, shady conditions the plants prefer.
If you ever want to limit the size of your hosta plant, constricting the container size is an effective way to do this. If you simply don’t transplant the hosta into a larger planter when you otherwise would, it will be limited to the maximum size of the container it’s in. It will not hurt your hosta plant to go without changing containers even if the plant seems to have outgrown the pot it is growing in. In other words, the only reason to upgrade the container size for one of your hosta plants is if you want that hosta to increase in size.
Keep Things Moist Enough for Shade-Loving Hostas
One of the major differences between hostas and most other plants you may have worked with is that hostas love shade and moisture. While your other garden plants probably enjoy getting nice and dry between waterings, your hostas will appreciate a more even-handed application of moisture.
Plants growing in containers are naturally susceptible to increased evaporation compared to plants growing directly in the ground. This is because they simply have less soil to cushion them from the effects of the environment, such as the wind and water.
Make sure that the place where your hostas will grow offers a bit of protective shade. If the container is left in full sun, it’s likely to dry out no matter how moist the soil initially was. Smaller containers also tend to dry out more quickly than larger containers, so if your hostas are growing in a small pot, you may find that you need to re-hydrate them pretty frequently.
Unless your area naturally provides a steady diet of precipitation, you’ll need to provide your hostas with enough moisture to meet their needs. This doesn’t simply mean making sure the plants get watered frequently enough. It’s also important to make sure the watering is deep enough, or that enough water is being given during the watering session.
No matter how deeply you water, when the weather is warm you will need to provide moisture more frequently. Plants may require water more than once per day during these times of year.
Make sure to target the stream of water at the base of the plant so that the moisture can be absorbed by its roots. Sometimes gardeners have a tendency to splash water around on the surrounding soil or onto the foliage of the plants. The water cannot be used by the plants when it lands in these places. Not only that, but it can also put plants at risk for fungal disease when they are exposed to excess moisture. For all these reasons, aim water at the base of your hostas when you water. The water should also be aimed under the leaf canopy and around the crowns.
Provide a “deep” watering by continuing to allow the water to flow until the moisture has had a chance to penetrate the soil by at least a few inches. When you have provided a deep watering, water will be flowing out of the drainage holes as long as your hosta planter has sufficient drainage. Your hosta plant will perform best if you provide deeper waterings every once in a while. It prefers this strategy to lots of shallow waterings that are more frequent.
You’ll know when it is time to water hostas because they will show you by wilting. As long as you water the plants soon after they show signs of fainting, they will not be damaged by wilting a bit now and then. Once you have watered the hostas, they will bounce back and recover.
Use Mulch to Keep Hostas Cool
A layer of mulch can also go a long way toward helping the soil where hostas are growing retain moisture. Mulch helps to insulate the soil to protect it from temperature fluctuations, and mulched soil will maintain a more moderate, balanced temperature than soil without a protective layer of mulch.
Use an organic mulch material like shredded bark, shredded leaves, or well-rotted compost. Spread a layer about three inches thick around the entire area where hostas are planted. However, do not touch the mulch material to the plant foliage, as this can help promote the spread of disease in your garden. Instead, leave a gap of a few inches between the mulch material and plant life.
Prepare Hostas for Winter
The good thing about growing hostas in containers is that they’re portable when you need to move them before inclement weather moves in. Hostas can be damaged if the temperature drops below freezing, or 32 degrees Fahrenheit. So if temperatures in your area will plunge under the 32-degree mark, you have a couple of options.
If it’s just a matter of a few degrees and the cold snap will not last for a long time, you can use a short-term solution. Simply move your hostas so that they are planted directly in the ground. The soil will provide more insulation against the falling temperatures than the breezy conditions of the container. If you want to make removal really easy, you can simply bury the hosta under the surface of the soil while it’s still planted in its container.
Another option you have includes wrapping the containers in blankets or freeze cloth to provide some insulation. This will work best if temperatures won’t get too far under freezing and won’t stay there too long.
If temperatures will plummet below freezing in your area, the only way to protect your hostas is to bring them indoors. You may have room in your home or on a patio to house your hosta collection. If you don’t have this kind of space indoors, consider keeping your hostas in the somewhat sheltered space of a porch, patio, or shed.
Wintertime is also the right time to prune your hostas that grow in containers. Wait until after the first frost to start pruning. However, do not prune while hosta leaves are green. You may have to wait a while after the first frost for them to turn brown. Then cut the hostas back by about a third.
Your hostas will not need as much water as usual while they are dormant during the winter season. You will only need to water them once every month or so, but do be sure as always to provide them with a deep watering.
Now you know how to provide your hostas that grow in containers with the best care all year round.