Hollyhock Alcea rosea 'Nigra'

Sow February to March or September to October. Sow seeds onto the surface of a good, free-draining, damp, seed compost. Cover with a very fine sprinkling of compost or vermiculite. Place in a propagator or seal container inside a polythene bag at a temperature of 15-20C until after germination which usually takes 14-21 days. Do not exclude light as this helps germination. Alternatively, sow in late summer in a cool greenhouse and then overwinter plants in cool, well lit conditions. Plant out the following spring. This method produces larger plants and is recommended if the soil is heavy or badly drained.Transplant seedlings when large enough to handle into trays or 7.5cm pots. Gradually acclimatise plants to cooler conditions for a few weeks before planting out after all risk of frost 45cm apart.

Grown as a biennial flowering plant, Black Hollyhock will grow quickly, establishing a deep root system. The plants will then wilt on the surface due to the freezing temperatures of winter, later returning the following spring. Biennials such as this are known to flower the second year. You can however achieve blooms in the first growing season, if the plants are started early enough. Hollyhock plants are known to readily self seed, so they are often seen as a perennial flowering plant. The seeds can either be collected at the end of the season, when all of the blooms have dried out, or they can drop to the bare ground beneath.

Rust remedies
Hollyhocks are archetypal cottage garden plants (you often see them growing beautifully in churchyards). The cleaner, sulphur-free air that we all now enjoy, however, means that fungus on roses and hollyhocks is more common. Both plants need tinkering to be at their best.

Rust fungus forms little pustules on the underside of hollyhock basal leaves and often spreads from there up the stem. If you want to grow your hollyhocks right by a path, as , they need to look vigorous and healthy. The only way to guarantee this is to use fungicides. If Bordeaux mixture, a traditional copper sulphate-derived remedy, is not enough to hold rust at bay, you may need to use stronger fungicides.

If this all feels far too much like chemical warfare, ignore any rust problems and hide the foliage of your hollyhocks by putting them nearer the back of the border.

Make more plants
Hollyhocks self-sow, so once you have introduced them they should spring up of their own volition, but they will creep to the sunny, open front of the bed. Watch out for this and dig some up and put them further back out of the limelight to get a balanced sweep. Don't transfer them directly, though – they need a short spell of TLC.

Dig up self-sown seedlings and pot them into a 7cm pot. Once the roots have filled it, move them on into a slim, deep pot to accommodate the tap root.

Read more frequently asked questions about growing Hollyhock seeds