Hollyhocks, Alcea rosea
Cold north-west winds are bringing showers of rain and, later, perhaps a little sleet or snow. It’s a day for staying indoors in front of a fire. But outside the kitchen window, dried seedheads of Hollyhocks move in the breeze and remind me of the glories of summer.
Hollyhocks, Alcea rosea, are magnificent plants. Short-lived perennials in the mallow family, Malvaceae, they grow upwards from a few basal leaves to form a flower spike six feet (two metres) or more, often reaching nine feet (three metres) tall. The flowers come in various colours – shades of pink, white, red, yellow and even a dark maroon that verges on black. They are an essential cottage garden flower.
Hollyhocks like well-drained soil and even thrive in cracks in paving and in gravel. A Hollyhock does best when it has enough root depth – a deep tap root enables the plant to reach deep underground for water and nutrients, as well as anchoring the plant against the wind.
Hollyhocks are easily grown from seed. If you sow seed in late June or early July in a seedbed in the garden or a seed tray of peat-free compost, you should have seedlings ready to plant out by the end of the summer. Seed can also be sown in a cool greenhouse in late summer and the seedlings planted out in spring. Either way, the plants will flower the next summer, from June onwards.
Packets of mixed flower colours are available and I enjoy the whole range of colours that are available.
I will only grow Hollyhocks with single flowers, such as the one pictured above. I tried to buy Hollyhock plants from my local garden centre a couple of summers ago, but all the plants had double flowers. These are a lot less attractive and are utterly useless to bees and other pollinating insects.They are best avoided. Unfortunately, double flowered Hollyhocks are available in most seed catalogues as well.
A Hollyhock plant will flower several times, but after a few years it will die off. Some authors recommend cutting off the spent flower spike after flowering, as a way to prolong the plant’s life. However, the plant will die after a few years anyway and leaving the spikes alone will allow your Hollyhocks to self seed. Self-sown plants often crop up in interesting and unexpected places and come in unexpected colours, which to my mind increases their interest in the garden. Self-seeding means there is no need to keep buying seed, either. (If you don’t like Hollyhocks or have too many, the young seedlings are very easy to pull out, so this habit of self-seeding is not much of a nuisance.)
Hollyhocks are edible. The young leaves have a mild flavour and can be eaten raw or cooked, although the Plants For A Future website admits that “the texture leaves something to be desired”. The flower petals and flower buds can be added as a raw ingredient to salads, adding colour more than flavour. The root contains starch and a refreshing tea can be made from the flower petals. A Hollyhock infusion may be used to treat a sore throat and a poultice can soothe inflammation.
Hollyhocks have one drawback: Hollyhock Rust, a fungal infection by Puccinia malvacearum. The fungus also infects other members of the Malvaceae, including Malva, Abutilon, Hibiscus, Lavatera, Malvastrum and Sidalcea. My Hollyhocks show symptoms every year, as does my Musk Mallow (Malva moschata). Yellow or orange spots appear on the upper surfaces of the leaves, with reddish-brown pustules on the lower surfaces. The pustules spread onto the stems and calyces of affected plants. The disease is rather unsightly and can reduce the vigour of plants.
Hollyhock Rust appears to be almost inevitable, as the basidiospores produced by the fungus easily spread in air currents from one plant to another and to Hollyhocks from other species including the Common Mallow, Malva sylvestris, which is a common weed in our area. Some authors recommend the use of fungicides but I don’t use them and I’m happy to have rusty Hollyhocks – there are many worse things and the flowers of infected plants still look lovely. Several fungicides previously recommended for use against Hollyhock Rust are now being withdrawn and, anyway, spraying with fungicides may suppress the fungus without killing it, so plants will still pass on the infection.
Feeding Hollyhock plants with compost in spring will help them to grow stongly and not suffer too much from rust. Ensuring good air circulation can also discourage rust.
We leave our Hollyhocks’ dead flower spikes over the winter and by doing this we have provided a home for the larvae of the Hollyhock Seed Moth, Pexicopia malvella. This tiny moth (wingspan 17-20 mm) flies from early June to mid August and we recorded it in the summers of 2014 and 2015 in our back garden. Its larvae feed inside Hollyhock seeds (and those of Marsh Mallow, Althaea officinalis) and then overwinter in a cocoon constructed inside the larval workings.
The species is rare and is in decline. This might be partly because fewer people grow Hollyhocks these days and those that do may be destroying the moth’s habitat by cutting off flower spikes after flowering. The moth may also be overlooked, as it is not the most colourful and spectacular of insects. Without the excellent Norfolk Moths and UK Moths websites and the book “Field Guide to the Micro-moths of Great Britain & Ireland” by Phil Sterling and Mark Parsons, illustrated by Richard Lewington (British Wildlife Publishing, 2012), we would have been unable to make an identification.
In Norfolk, the Hollyhock Seed Moth was recorded at Hickling Nature Reserve from 1957 until 1989, in Norwich in July 1987 and in the Berney Marshes / Reedham area in 1994. Ours are the first records since. Thanks to Tony Irwin (who recorded the moth in his garden on Earlham Road in Norwich in 1987) for taking a look at one of our specimens (pictured above) and confirming the identification.