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A wide variety of plants growing in the Medieval Herb Garden on a sunny day

Medieval herb garden blog 66: Crab apple

Wednesday, April 15, 2026

Week 66 volunteer update

We tackled the Russian tarragon and the buddleja mint last week. Today, it was time to chop back the soapwort. This, as usual, had run rampant. It was encroaching over three levels of the Medieval Herb Garden.

We then potted-on some goat’s rue and pulled some rhubarb. The rhubarb has done really well this year despite one plant already having “gone-to-seed”.

A very tall stalk of rhubarb with large green leaf - as tall as a nearby information panel that reaches waist height!

That's one mighty bit of rhubarb!

We had quite a few visitors in today. Carole spoke with a lovely couple from Cologne. A Japanese family thanked Kim for her hard work in making the garden look lovely.

Carole did the weekly flower count. She then decided which of the 160 plants to include in her first free talk of the year. It's on Saturday 18 April, 1pm to 2:30pm. Please come along if you are free.

In a previous blog, we had asked for donations of 5L plant pots that anyone had to spare. So, a big “thank you” to everyone who has kindly brought some in. They are already being put to use.

Plant of the week: Crab apple (malus sylvestris)

'Malus' is the Latin name for 'apple tree' or 'apple'. 'Sylvestris' means 'of the woods / forest', coming from 'silva' ('forest / woodland'). So, a literal translation is 'forest apple'.

The English name 'crab apple' may refer to the tree's "crabbed" or gnarled appearance.

Crab apple is native to the UK and Europe. It is a deciduous tree. It can grow up to 30ft (9 metres) high. Crab apple trees can grow almost anywhere, but cannot survive in waterlogged areas. Ideally, it also needs 6 hours of light a day.

The trunk of a crab apple has a greyish-brown, flecked bark. The tree can become quite gnarled and twisted.

The crown of a crab apple tree is irregularly dome-shaped and densely branched. Domesticated apple trees tend to be more loosely arranged with fewer, straighter branches.

The leaf buds are brown and pointed. They grow on short stalks and have downy hair on their tips. The shiny, green leaves are 1.25 to 4 inches (3 to 10 cm) long. They are alternate and simple, with a serrated edge. The leaves have a smooth upper surface and fine hairs on the underside.

A small crab apple tree in flower with bright white flowers growing on the end of brown gnarled branches

Crab apple in flower in the Medieval Herb Garden

Crab apple flowers in spring. The flowers are borne in corymbs (a cluster with a flat head) and have five petals. They can be white, pink or red. The expanded flowers can be 1.5 inch (4 cm) across.

Crab apple flowers are often self-fertile. They are also excellent pollinators for other apple trees.

The fruit is a 'globose pome' (outer fleshy layer surrounding a central core with seeds). It varies in size from 0.5 to 2.5 inches (1 to 6 cm) across. The fruits can vary in colour from yellow to bright red. The centre of the fruit contains five carpels arranged star-like, each containing one or two seeds.

Crab apple trees have a non-invasive, fibrous root system. This generally spreads 3 to 4 feet (0.9 to 1.2 m) from the trunk. The roots are found within the top 2 to 3 feet (0.6 to 0.9m) of soil.

Partially open white and pink five-petalled flowers with yellow sepals

Crab apple flowers in the Medieval Herb Garden

Culinary uses of crab apples

Crab apples are a natural source of pectin. They are used in making jams, jellies, cider and sparkling alcohol drinks.

Warning:

The seeds (pips) contain amygdalin, a cyanogenic glycoside. This can release cyanide. This causes symptoms like difficulty in breathing, trembling, and in severe cases, coma.

Use of crab apple as a dye plant

The crab apple (fruit, bark, and leaves) is rich in tannins. It produces light rosy reds, pinks, beige and yellows.

Deep-red crab apples and the bark give the most vibrant, lightfast colours.

A pink dye can also be made from the leaves. Peach or sage green dyes can be made from the flowers, depending on the mordant.

Folklore and other facts about crab apples

In Celtic culture, crab apples are second only to oaks in mythological significance. The folklore centres on love, magic, fertility, and true love. They often representing a gateway to the fae.

The tree was often part of wassailing rituals. Trees were toasted to banish evil spirits and ensure a good harvest.

The crab apple is one of the few host trees to the parasitic mistletoe, viscum album. The trees are often covered in lichens.

As Old English Wergulu, the crab apple is one of the nine plants invoked in the pagan Anglo-Saxon Nine Herbs Charm. This was recorded in the 900s.

The pinkish wood has an even texture. It makes good quality timber, lending itself particularly well to carving and turning. It also makes a sweetly-scented firewood.

In Scotland, the crab apple is the plant badge of Clan Lamont. Their Highland territories were around Cowal and Argyll.

In Britain, the crab apple is associated with 93 species of insect.

Medieval medicinal uses of crab apples*

Today, apples and crab apples are known to have many beneficial health properties. They can help with gastrointestinal issues. They are also used in skin care, treating scalp issues and making hair shiny.

In the Medieval period, crab apple juice was used to clean and heal minor wounds and cuts.

As John Gerard said in his 16th century 'Herbal': “The juice of wild apples or crabs taketh away the heat of burnings, scaldings, and all inflammations: and being laid on in short time after it is scalded, it keepeth it from blistering.”

*As always, this isn't to be considered medical advice today. Please don't use any plants mentioned in these blogs as medicine without advice from a doctor.

Medieval herb garden blogs

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