WHAT IS A MINIATURE HOSTA?

Growing Miniature Hostas

Planting Miniatures

Feeding Miniatures

Dividing Miniatures

Over-wintering miniature hostas.

Growing minis as Bonsai accent plants

Sue proctor hostas header

WHAT IS A MINIATURE HOSTA?

This is not such a simple question as it seems. The American Hosta Society (AHS) includes in its list of registered miniature hostas some that reach 9-10 inches in height – e.g. H. Hacksaw and H. Stiletto. These are designated minis because their leaf area is 6.0” sq. or less. This is the current way the Society defines minis – leaf area not height. Over the years the AHS has increased the size of minis at least twice, in response to popular demand. H. ‘Blue Mouse Ears’, for instance, is treated by almost everyone as a ‘mini’ yet the AHS designated it as a ‘small’ hosta until the last change in 2010. Our Catalogue gives the approximate height and leaf size of all our miniature and very small hostas.

In ideal growing conditions with plenty of water, some minis may eventually (4-6 years) exceed their mini status in size but most mini lovers will have divided and replanted well before then.

Our Catalogue gives both the expected mature height and leaf size of miniature and very small hostas. Hostas listed as miniature/very small hostas are those that fail to meet the AHS requirement for leaf size but are still 6”-7” in height.

Growing Miniature Hostas

Miniature hostas look great planted together in bowls, separately in pots, or in gravel beds. Some of the more vigorous varieties also look good as edging plants or on rockeries, but since they don’t spread rapidly make sure they can’t easily be smothered by faster growing and spreading plants.

Most miniature Hostas are trouble free but the less vigorous and more slow growing varieties do need a little care, particularly during their first year or two when their root balls are small. If you choose these varieties, we will always let you know before you confirm your order.

The secret of growing miniature hostas well is to make sure they have really good drainage. Miniatures need a lot of air around their roots and hate sitting in waterlogged compost, particularly over winter when wetness combined with a hard freeze can cause root rot. See ‘Over-wintering miniature hostas’ below.

Planting Miniatures

Miniatures like a light, well-aerated compost so if your garden is peat-free then you will need to add about 40% grit, sharp sand or Perlite to organic composts. Even if you plant in a peat or peat substitute compost add about 20% grit or perlite. Use a good-quality compost, not a cheap compost made from green waste. Some cheap organic composts can become very silty when wet.

If planting in a trough or bowl make sure it is deep enough to allow a layer of pea gravel beneath the compost to aid drainage. 4-5” depth of compost will ensure that your miniatures will grow to their full mature size. Less than this and mature size may be reduced.

When you buy a miniature hosta mail-order you will sometimes find little plantlets fall away from around the main stem. Don’t be tempted to plant these separately. They will almost certainly die.

The most fragile hostas, e.g. Pandora’s Box, Tiny Tears, need particular care until they have a good root system. In general the smaller the mature leaf size, the more care is needed. These minis should not be allowed to become waterlogged, particularly over winter, or dry out during the growing season. They also need good light to stimulate growth. If small leaf size is important to you, it is often best to choose more vigorous varieties and restrict their room for root growth. This will result in a smaller leaf size. See ‘Growing minis as Bonsai accent plants’ below.

Feeding Miniatures

If you are planting between April and mid-July add a slow release granular fertiliser to the compost. If planting later in the season wait until the following spring to add the fertiliser when it can be forked gently into the compost as the hostas begin their new growth. You can also give them an initial boost by using a weak seaweed feed between March and May. White-centred minis, i.e. those with little chlorophyll in their leaves, benefit from a weak feed through the summer, but do not feed after July, when the hosta is beginning to slow down for the winter. When choosing a fertiliser, choose one with 10-20 nitrogen content.

Dividing Miniatures

The best time to divide minis is when they are growing most strongly, i.e. between May and July. Before you divide, check that the root ball is a good size and that the plant has multiple eyes (leaf buds). To divide, depending on the size of the plant, we use a sharp bread knife or a cheap disposable blade craft knife, extending the blade for about 3”-4”. Cut carefully through the crown and tease the roots apart. The rule for dividing is: ‘Don’t be too greedy!’ The more divisions you try to get out of one plant the more chance there will be of losses.

Over-wintering miniature hostas.

All hostas benefit from about 4-6 weeks dormancy in winter - temperatures below 4C. or 40F, so over-wintering minis outside should not be a problem providing they have really good drainage. Cold won't kill a mini but being waterlogged, frozen, thawed and frozen might, particularly during its first year of growth. A danger point for minis left outside is when there is a severe frost followed by a quick thaw. This can result is a little pool of water around the crown of the plant which can’t soak away because of the frozen soil beneath. Sharp sand or alpine grit around the crown will reduce the chances of crown rot. To be on the safe side, you can mulch your minis with bark chippings.

Many people bring minis planted in troughs or bowls under cover during winter. A porch or car port is ideal. This protects the hostas against getting waterlogged by thick snow and winter rain and makes sure they get plenty of ventilation. Never bring minis indoors during winter – even into a conservatory. Put your minis outside again mid-late February and water from then on. We over-winter our 100+ display minis in 1-2 litre pots in a cold greenhouse, opening the doors and windows whenever the weather is mild.

These notes can only cover the basics. If you have any questions please give us a ring: Tel 01484 866189, Mobile 07917 006636 or e-mail us: hostas@sueproctorplants.co.uk

Growing minis as Bonsai accent plants

Most minis will grow well in very small containers. If their root growth is restricted, then they will grow more slowly and their leaf size will be smaller. An accent pot about 4” diameter and 2” deep is ideal, though we have grown minis in an accent pot almost half this size. The only problem with a very small pot, apart from making sure it doesn’t dry out, is that root growth can push the plant upwards, out of its compost. When this happens you can either trim the roots and re-plant, or, if the plant has 4-5 eyes or more, divide it.

Some Bonsai enthusiasts have their own compost formula which is also good for accent plants – a favourite is a 1/3rd peat-based compost, 1/3rd fine grit or cracker grit, available from stone masons, and 1/3rd Akadama potting medium, available from bonsai suppliers. If you want a cheaper alternative to Akadama, Google ‘Bonsai Cat Litter’!