Hostas are a beautiful addition to container plantings and play well with other foliage textures. Look for variegated and striped varieties to create an interesting focal point.
In autumn, move potted hostas to a sheltered location like a garage or shed for the winter. Be sparing with water; dormant plants require only a fraction of the moisture of actively growing ones.
Watering
Hostas are fast-growing perennial plants that need plenty of water to sustain growth. They need a minimum of 1 inch of rain or supplemental water each week during the growing season.
When you plant hostas in containers, choose a large pot made of breathable material such as terra-cotta and make sure it has good drainage. Use a high-quality potting mix that doesn’t contain “moisture crystals” or other water-retaining polymers, as these can contribute to rot during the winter.
Choose a location that provides partial shade and a consistently cool temperature. Hostas in containers often need less sunlight than those planted in the garden.
Hostas go dormant in the winter and are best stored in a sheltered place like a garage or shed, where they can stay cool and dry. They can also be left out on a protected deck or porch as long as the weather stays warm and dry. Hostas that are left outside in the winter need to be watered a few times per month to keep them from drying out.
Fertilizing
Hostas are fairly drought tolerant in the ground but they need regular watering in pots. They should be watered a few times a week or more during hot weather to keep the soil evenly moist.
Hostas in containers have less of a need for fertilizer than plants planted in the ground but they do benefit from a spring application of slow-release liquid fertilizer. Foliar applications of a liquid or water-soluble fertilizer can also be useful in the summer when plant growth is at its peak.
When selecting a container for hostas, consider the eventual size of the plant. A large variety like ‘Empress Wu’ will not grow to its full potential in a pot, but it can still look lovely. Smaller varieties, such as ‘Mouse Ears’ or ‘Pandora’s Box’ are great filler plants in mixed containers with other foliage plants like ferns and begonias. They also look nice as a single specimen in the shade garden.
Pruning
Hostas can grow to be quite large in the ground, but they will likely mature a bit smaller when planted in containers. Select cultivars with attractive foliage shapes and colors like variegated, heart-shaped or crinkled leaves for the best look. Consider grouping hostas together in a garden or by the entrance to your house for a pretty display.
When it comes to pruning, removing old foliage is important for the health of your plant. Doing so prevents fungi and bacteria that invade wounds in the leaves from spreading to the rest of the plant.
Once the weather turns cold, mulch your hostas with 3 to 4 inches of pine straw or wood chips. This layer insulates them from extreme temperature shifts, while also preventing the soil from becoming waterlogged. Avoid putting mulch too close to the crown of your plants to reduce the risk of crown rot. In the spring, remove any mulch that has built up around your hostas.
Slug Control
Slugs are one of the few pests that can kill hostas. They eat leaves, flower buds, stems, corms, and bulbs. They leave behind rasping holes in the foliage, and are active at night. Hostas are more likely to be damaged by slugs when conditions are warm and moist.
Handpicking and crushing slugs, especially after dark, is an effective control. It also helps to place overturned flower pots, boards, shingles, inverted grapefruit halves or commercially available slug and snail traps around the garden to serve as daytime shelter for slugs and snails.
Sprinkling coffee grounds, wood ashes, sand or diatomaceous earth (DE) is another good barrier. It works because the fine particles cut and desiccate slug skin as they crawl over it. Copper rings are another deterrent — if a slug crawls over one it receives a small electrical shock that sends it running the other way. Try to use a chemical only as a last resort, since they can harm beneficial insects and frogs and toads.