Are hostas house plants...no, can they be grown indoors...yes. With outdoor space limited, especially in urban areas of the UK, we are often asked whether hostas can be grown in indoors. At the Chelsea Flower Show it is the second most asked question after 'how do you keep the slugs off your hostas?'.
Hostas are an incredibly diverse genus and there are varieties for every garden or indeed...house. With lush foliage and architectural form, hostas have the perfect look to freshen up a room.
What you need to know before growing hostas indoors
The most important thing to know before growing hostas indoors is that they absolutely need a dormancy period. When grown outdoors, hostas will die back for the Winter months from around November to February. After dormancy, hostas return with fresh new growth in the Spring and often emerge large than the previous year. Hostas require a dormancy of around 12 weeks minimum at around 5 degrees or lower to ensure vigour and health for the following season. If left inside in the warm, hostas do not know when it is time to die back for the Winter. If hostas do not get a dormancy they will simply run out of steam, look sickly or die.
Hostas will need to be put outside in the garden around October to start the process of dormancy, they should not be brought inside again until late February, you can do this earlier but expect your hostas no look their best later in the Summer. If you live in an block of flats and have a balcony that would also work. It can get tricky if you have no outside space at all. We have heard of people in the states, in areas such as LA, who actually put there hostas in the freezer for 3 months to give them an artificial dormancy. This isn't something we've tried but might be worth a go (at your own risk) if you haven't got any outside space.
What hostas can I grow indoors?
Due to their need for a dormancy period, it is usually wise to only grow hostas indoors that you will be able to move outside without too much difficulty. For this reason, we would recommend avoiding all large and giant varieties. Small and miniature varieties make good house plants, as they are easy to move around, they'll fit on the window sill and you can grow several together nicely.
The colours of varieties that are best used will depend on the light level in the area you would like them. It goes by the same rule as if they were outside the darker the leaf (such as blue) the less light they want, the lighter the leaf (such as yellow) the more light they can take.
Other issues with growing hostas indoors
Growing hostas outside normally comes with a fair amount of battling against the slugs and snails, although you won't have this issues inside (at least I would hope not), you will have to be aware of some issues hostas can have if grown inside. Red spider mite is a common pest for plants grown in very hot conditions such as a glass house or potentially in your case a conservatory, these may require treatment if the mite gets bad. See information on the RHS website about red spider mite - Red Spide Mite.
A common issue with growing hostas indoors is maintaining a good level of moisture in the soil, with constant warmth, air conditioning and whatever else, their soil can dry out far quicker than it may outside. Make sure that if your hosta becomes heavily rooted in its pot you repot into a larger one, this will help with maintaining moisture levels.
Aphids, fungus gnats, and other houseplant pests can be a problem for hostas grown indoors. Keeping a close eye on your plants as you would any house plant is important.