Frequently Asked Questions About Hostas

Hosta 'Blue Angel' and Hosta 'Sum and Substance' at the Hanging Hosta Garden, Lindford ©June Colley
1. How do I stop slugs and snails from ruining my hostas?
Slug and snail damage can be reduced or even eradicated. See our recommendations

2. Can I grow hostas in containers?
Hostas are undoubtedly one of the most attractive foliage plants for growing in containers, whether in a shaded courtyard, on a paved terrace or placed on a flight of steps. Pots and containers come in many different shapes and sizes but all have one thing in common: they provide happy habitats for slugs and snails.

The best way to prevent this is to place wire mesh at the bottom of the empty pot before adding the necessary crocks so that predators cannot access the plant through the drainage hole. A further preventive measure is to raise the pots on feet in a saucer or similar shallow container filled with water because slugs cannot swim! The hosta and its pot should not be in contact with the water. When dealing with mollusc damage in general, good garden husbandry goes a long way to preventing unwelcome infestation. Slugs and snails tend to lurk in dark corners, under overhanging terrace edges and in dry stone walls or old walls with damaged pointing.

Hosta can be repotted when their roots grow out through the bottom of their pot. This can be up to once every year, whislt they are still reaching their mature size. Hostas prefer to be in pots which restrict their roots rather than those which are too big for them, with a lot of soil between them and the sides of the pot. A general guide is to only move them up one pot size every re-pot. This can also be a good time to split your plants. See our guide to dividng hostas. Don't forget to sterilize your tools after you've finished dividing your plant.
A display of hostas in their pots.
3. How do I overwinter hostas?
Hostas are very hardy perennials and don't generally require any special treatment over the winter period. In the right conditions, they can endure temperatures below -30 deg C and, provided that their roots have been allowed to grow sufficiently well to anchor them in the soil, they can withstand many freeze-thaw cycles. In fact, hostas need a period of dormancy during winter to ensure that they are able to thrive during the subsequent season; One month of daytime temperatures below 5 deg C is generally sufficient. What the minature varieties in particular are less forgiving of however, is a combination of cold, wet soil and poor drainage. This can sometimes be an issue for pot-grown hostas; if their root-ball freezes and then they are watered, the frozen rootball may prevent adequate drainage causing the plant to rot. Whilst this is far from a common occurance, some people like to over-winter their pot-grown mini hostas in an unheated garage or greenhouse where they can control the weatering or alternatively sit the pots on their side during winter.

4. How do I divide my hostas?
See our guide to dividng hostas.

5. How many species of hosta are there?
There are generally recognised to be about 42 species of hosta, however some taxonomisits put that number as low as 24. The reason for this is that several varieties of hosta, originally thought to be species, are now believed to be hybrids originating from Europe. Examples of these include H. fortunei (now H. Fortunei, to denote it as a cultivar rather than a species) and H. crispula (now H.Crispula). Because the records of how, where and when many species of hosta were originally found are old and incomplete, it has not always been easy to verify their classification accurately. This is further complicated by the fact that most species of hostas readily hybridise with others, so the classic definition of a species (which precludes them from breeding with other species) is of limited use. As a consequence, natural populations overlap and interbreed (a process called introgression), making their classification more difficult.

6. How many varieties of hosta are there?
There are around 5,800 officially registered varieties of hosta, with around 150-200 new hostas being registered each year. Additionally, there are many named but unregistered hostas. The exact number is difficult to quantify, but is probably around 2,000. Of this rather large total, over 2,000 varieties of hosta are readily available to be purchased by UK retail customers - at least whilst the UK remains in the EU Single Market, given that some of the biggest suppliers are based in the Netherlands. The registration process for hostas was established in 1968 (the same year that the American Hosta Society (AHS) was founded). It is overseen by the International Cultivar Registration Authority (ICRA) and was administered by the University of Minnesota until 2001 when the AHS took over the process. The main purpose of registration is to avoid confusion over the naming of hostas by ensuring that one name is assigned to one hosta with new conflict or duplication. It also provides an accurate, permanent and publicly available record record describing the main features of the plant.

7. Do hosta come true from seed?
Species of hosta do come true from seed, however cultivars (hybrids and sports) do not. This is true of the vast majority of plants. The fun and excitement of crossing two hosta species or hybrids together is in creating a genuinely new plant and not knowing exactly which characteristics it will have. There is always a possibility of producing a new, truely garden-worthy plant.