Hollyhocks set special accents in the flower bed in summer with their high flower spikes. This is how to plant the pretty summer bloomers in your garden.
Profile of common hollyhock:
Scientific name: Alcea rosea
Plant family: mallow family (Malvaceae)
Other names: hollyhock, holly-hock
Sowing time: August to September or May to June
Planting time: spring
Flowering period: July to September
Soil quality: gritty to loamy, nutrient rich, humus rich, tolerates lime
These information are for temperate climate!
Use in: flower beds, bouquets, group planting, rose companion, cottage garden, flower garden, heather garden, natural garden, rose garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 6 (-23 °C / -5 °F)
Bee and insect friendly: Yes
Plant characteristics and classification of common hollyhock
Plant order, origin and occurrence of common hollyhock
Hollyhocks (Alcea) form their own genus with about 60 species within the mallow family (Malvaceae). They come from the eastern Mediterranean and have been native to Europe and Asia for some time, where they were used as a useful plant for medicinal purposes and for coloring food. The common hollyhock (Alcea rosea), also known as hollyhock or farmer’s rose, is the most popular representative and is often used as an ornamental plant in the garden. Mallow plants were already known as medicinal plants in ancient Rome. There the hollyhock got the Latin name Alcea. Later the Greek name Althea (= to heal) was used in the botanical nomenclature, which is why the hollyhock is still sometimes sold under this name.
Characteristics of common hollyhock
The hollyhock is characterized by its tall growth of up to two meters (6 ft 8 in). The hollyhock is biennial, which means that in the first year only the leaf rosette is formed, in the second a long, straight stem grows from it. Spikes with striking, large flowers in many beautiful colors form on it. The stem of the hollyhock is not branched and strong and grows straight up. The entire plant is covered with slightly spiky hair.
The multi-lobed, light green leaves of the hollyhock grow from a basal leaf rosette. The leaves are up to 16 centimeters (6.4 in) and are slightly hairy. They sit on hairy stems. In the second year, alternate leaves grow on the flower stem.
The strong, palm-sized flowers of the common hollyhock appear from July to September. They are available both single and double in a wide variety of colors from white to yellow, apricot, pink or red to violet and purple black.
Tip: Single flowering varieties are considered to be more persistent than filled hollyhocks.
Common hollyhock – cultivation and care
Hollyhocks like to be in full sun. The best place for your hollyhock is to choose a sunny bed with well-drained soil. Too closely sown or planted stands should be thinned out so that the individual plants can develop more vigorously. The leaves also dry better and are less susceptible to mallow rust.
Hollyhocks like a nutrient-rich, well-drained and dry to slightly moist soil.
Planting and Sowing
Plant hollyhocks with enough space between the plants so that the leaves can dry quickly after a downpour. The following spring, the hollyhock gets a fertilization with compost. In summer, the fast growing plants need plenty of water. A protective mulch layer is advisable so that the soil does not dry out so quickly. Support the long stems in unprotected locations with a stable rod, as hollyhocks bend slightly in the wind.
Hollyhocks can also be cultivated in seed trays. The seeds in the loosened substrate are covered with a thin layer of soil (need dark to germ) and watered. After two to three weeks, the first seedlings appear, which must then be separated. The young plants only form leaves in the first year. Next spring they start with well-developed rosettes and then show their flowers all summer long.
Tip: Do not wait too long before pricking and later planting out, as hollyhocks like to grow deep root and it quickly becomes too narrow for them in the flat seed trays.
The more sunrays spread over the common hollyhock, the higher the water requirement. On hot summer days, it may be necessary to water both in the early morning and in the evening. A short finger test provides information about the current state of the earth. If the upper layer feel dry, they need to be watered.
Please water directly onto the root disc. Irrigation on the leaves are a welcome target for pathogens and pests. Avoid watering in the blazing midday sun. Every drop of water on the leaves turns into a burning glass, which can lead to fatal burns.
For an optimal availability of nutrients, the common hollyhock growth strong and shows abundant flower formation. This is how to properly fertilize the summer beauty:
- Fertilize every 4 weeks from June to the end of flowering with compost and horn shavings
- Give the first portion of compost from the second year at the end of April
- Slightly add organic fertilizer into the soil and pour
If a hollyhock grows in a bucket, it is recommended using liquid fertilizer for flowering plants. Since potting soil is pre-fertilized for 4 to 6 weeks, only start to supply nutrients after this period so that there is no overdose. Please do not apply mineral-organic preparations to dried substrates. First water clear tap water before adding the agent.
Hollyhocks are basically perennials. However, since they spend a lot on flowering, the blooming decreases significantly from year to year. It is therefore better to cut back some of the flowered plants and to ensure a permanent rejuvenation by sowing. The common hollyhocks are sown directly in the bed either in autumn or from June. If early young plants are planted in early autumn, the mallow can still develop well before flowering next year.
Pruning after fading prevents undesired self-seeding and extends the flowering period.
Tip: Biennial plants usually die after ripening. Shortening the plants immediately after they have faded, often leads to a renewal of the leaf rosette and a further bloom in the following year.
Hollyhocks like to seed itself. In order to promote self-sowing, you should leave the seed heads in winter and only remove them in the next spring. Alternatively, you can collect the seeds and spread them in a targeted manner. A safe sign of ripe hollyhock seeds are dry capsules that can be opened or pressed on easily. The individual seeds are very small, colored brown and can be easily triggered. If sown immediately after collecting in August or September, the hollyhocks will form a strong rosette next year and flowering the following year. Depending on the region, weather, seeds and some other factors, the seeds can sometimes germinate in autumn and bloom in the next year. Alternatively, you can take your time until late spring or early summer and sow directly into the prepared bed.
Diseases and pests
The main disease of hollyhocks is the mallow rust (Puccinia malvacearum), which occurs so often that it almost belongs to the hollyhocks. It mainly affects the leaves and is recognizable by yellowish spots and reddish-brown pustules (spore beds) on the underside of the leaves. The hollyhocks are increasingly fading, even if the plants continue to bloom.
In the event of infestation, continuously remove the infected leaves and dispose of them in the household waste. A fungicide stops further spreading. In autumn, the plant should be cut back completely and piled up with soil. Also remove this soil and the first new leaves in spring. To prevent infestation with mallow rust, the hollyhocks should be planted at a sufficient distance in a suitable, airy location and never poured over the leaves.
Hollyhocks are biennial and do not normally need winter protection. The aerial part of the plant dies in winter and can be cut off. The plant will sprout again next spring. If you want to be on the safe side, you can cover the hollyhock with leaves or brushwood in frost.
Use in the garden
Hollyhock is a popular cottage garden plant. Since it needs support, it is only suitable for the perennial border as a location with sufficient support. Hollyhocks, on the other hand, have a great effect in front of house walls, walls or along fences and as an attractive background for herbaceous and flower beds. Planted in groups, they also come into their own in borders and provide splashes of color at lofty heights.
In romantic country house gardens, hollyhocks accompany larkspur, sunflowers, phlox and roses with their persistent bloom. The long flower panicles of the hollyhock also look good as cut flowers. To prolong the flowering time in the vase, the leaves of the flower stem are removed from hollyhocks and the stem end is immersed in boiling water for 40 seconds.
- ‘Polar Star’ (white with a yellow eye) and ‘Mars Magic’ (red) are part of the single flower, long-lasting Spotlight varieties.
- The hollyhock ‘Nigra’ blooms in dark purple to almost black.
- Fine blossoms from creamy white to apricot, on the other hand, characterize the flowers of the Hollyhock variety ‘Champagne’. It is also suitable for pots and is around 1.70 meters (5 ft 8 in) high.
- The red-violet, double flowers of the Hollyhock ‘Cassis Swirl’ are somewhat reminiscent of English roses.