Small deciduous shrub, native to North America and Asia; there are about five hundred species of potentilla, spread all over the globe, only some of which are grown as ornamental plants. It has an erect habit, slightly roundish, with semi-woody, erect, rigid, very thin and densely branched stems; the leaves are light green, are wrinkled, with deeply marked veins, the margin is serrated and some varieties have deeply divided leaves.
From May until the first colds produce numerous small cup-shaped flowers, yellow, red or pink. Very used as border plants or in rocky gardens, they generally remain smaller than 50-60 cm.
Potentillas are rarely showy plants, but they are very useful for their resistance, for the long flowering season and for the wide range of colors and portions available. This makes them ideal for flowerbeds, mixed borders and even for rock gardens, as long as the light and soil conditions are compatible with their needs.
They are perennial herbaceous belonging to the Rosaceae family. The genus includes more than 500 species among annuals, biennials and perennials. They are widespread in almost the entire northern hemisphere, from mountains to meadows. They generally prefer alkaline soils.
Some species are also widespread in Italy in the spontaneous state (some are, inter alia, pests that are rather difficult to eradicate, to which great attention must always be paid). On the other hand, those sold in nurseries to be included in gardens are almost all of Asian origin. In particular, almost all come from the Himalayan area, from China and Siberia.
They are very rustic and can in some cases be confused with strawberries: the leaves and flowers, in fact, are remarkably similar.
The perennial species are cespitose and develop from fibrous roots, often stolonanti. The leaves are alternate and can be divided into pairs of opposite lobes and divided into 3-7 digitized segments, mostly toothed, with very pronounced ribs.
The flowers are simple, usually composed of 5 petals, saucer, cup-shaped or star-shaped and open from spring to autumn.
|Family and gender|
Fam. Rosaceae gen. potentilla more than 500 species
|Type of plant||Perennial herbaceous|
|Exposure||Full sun, half shade|
|Ground||Poor, well drained|
|Irrigation||Only in the event of prolonged drought|
|colors||Yellow, red, pink, white|
|Flowering||Depending on the species, from mid-spring to autumn|
|Propagation||Seed, division, cutting, offshoot|
|Crop care||Spring cleaning, possible containment, division of the head|
Place in a sunny or partially shaded place; in areas with a very hot climate it is good to shade the plants in the summer period. The potentillas do not fear the cold and can withstand temperatures close to -20 ° C without problems. Usually the most suitable exposure to potentille is full sun. However, some species can grow well even in partial shade or with a slight shade.
The cultivation of potentille is very simple and generally does not involve any kind of problem, especially once they are well freed.
Generally they are satisfied with the rains, being able to endure even long periods of drought; from march и september it is however good to water sporadically, waiting for the ground to be well dry between one watering and another. At the beginning of the vegetative period, in February-March, bury organic fertilizer at the base of the plant, or spread a slow release granular fertilizer around the stem.
In the open ground the distribution of water is rarely necessary. We can intervene sometimes after being planted and in cases of prolonged and very hot drought (especially on the coasts and in the Center-South).
The potentilas grow very well in any soil, although they need perfect drainage; they don't like excessively acid soils. Almost all soils are suitable, even if individual species have specific needs to grow and flourish at their best. In general we can say that too rich soils are to be avoided because they will stimulate leaf production, to the detriment, however, of flowering.
Generally they grow well on well-drained, moist and moderately fertile soils. Those coming from areas at high altitude need instead a gravel, very well drained and rather poor soil.
In spring the tufts of the previous year can be divided, the portions practiced should be immediately put to stay; in summer it is possible to take semi-woody cuttings, to be rooted in a mixture of peat and sand in equal parts; in autumn, ripe seeds are sown directly on the ground.
Pests and diseases
Typically, potentilas are not attacked by pests or diseases.
As we have said, the potentille tolerate the cold very well and most are able to withstand temperatures even below -20 ° C. They are therefore suitable for the whole of our peninsula, especially the mountain or semi-mountainous areas, even up to an altitude of 1500 meters.
Some species may instead have problems in the South and on the coasts because they do not like too draining and arid soils. If we live in these areas we therefore choose wisely.
Potentilla pot cultivation
Pot cultivation (especially for small or medium-sized species) is possible and quite simple. The ideal compote is formed by two parts of soil for flowering plants and a part of sand. For species that want more moisture we can instead create a mixture with 1/3 of soil, 1/3 of slightly calcareous garden soil and 1/3 of sand.
Clearly, they must always be prepared with a thick draining layer based on gravel, expanded clay or earthenware.
The irrigations must be regulated according to the type and in any case it is never advisable to let the soil dry completely. However, stagnation should be avoided.
To stimulate growth and flowering, a liquid fertilizer for flowering plants can be administered every 15 days, making sure that the nitrogen is only minimally present and that potassium is absolutely predominant.
These plants hardly need a supply of nutrients: most often they bloom and develop better on poor soils.
The best time to plant is the end of winter, when frost is no longer expected. The plants are usually sold in jars of 8 cm in diameter (or larger). A hole will be dug and, after having extracted the specimen and checked that the roots are free to grow in all directions, it will be inserted taking care that the level of the collar remains unchanged. We compact the soil and irrigate abundantly.
Pruning and cultivation treatments
Potentilla flowers appear on the vintage stems. It is therefore important to prune rather drastically to stimulate the production of new castings. The operation is carried out at the beginning of spring, before the vegetative restart. Shrubby bushes should be pruned so that they always remain compact: this prevents the base from being too bare over time, favoring the birth of new castings instead. It is therefore necessary to eliminate the oldest branches every year. The others must be shortened by half their length. Moreover, the new vegetation will bring many more flowers.
The varieties with prostrate bearing and ground cover have the tendency to widen thanks to their stoloning roots. If you want to prevent them from becoming intrusive, you need to work hard and keep the area clean, limiting their spread.
The potentilas multiply very easily by seed, but just as easily can be obtained thanks to the division or the cutting.
Sowing you can proceed when the minimum temperatures have reached 10 ° C.
You can use single jars, cassettes or alveolar trays, in a cold greenhouse or even outside. We distribute the seeds and cover them with soil or vermiculite, always keeping humidity high. Germination occurs in 2-4 weeks. It then proceeds to different toppings. Generally they are ready for transplanting from the autumn or the following spring.
Division it is advisable to regularly divide our bushes because the plants tend to deteriorate after a few years and rejuvenation is the only solution.
In autumn, the plants are extracted from the soil and the specimens are divided, leaving each one with roots and at least one eye.
Talea it is useful to preserve those cultivars that tend, over time, to lose the red coming back to yellow. We pick branches that produce flowers with colors that satisfy us. The best time is summer. Place them in a container with a mixture of earth and sand (or perlite). We keep it slightly damp until we notice the vegetative restart. At that point we will be able to put them in individual containers.
Potentilla fruticosa from Europe, Asia and North America. It is an erect, compact and very branched shrub. It can even reach 2 meters in height, continuously flowering from May to September.
It produces abundant corollas in shades of yellow. It is easy to grow and requires open and sunny exposures. It has been used to obtain numerous garden hybrids
Potentilla reptans originally from Italy and present almost everywhere in the spontaneous state. It should be kept under control because it becomes easily pest.
Potentilla recta europea, with leaves similar to fruticosa, it reaches even 70 cm in height. The stems are erect and very branched. The inflorescences form jets of yellow flowers with a diameter of about 3 cm.
Potentilla duvarica It is a shrub with a compact deciduous habit with a height of about 50 cm. It comes from China and Siberia. The branches are semi-detached, the white flowers, simple, about 3 cm in diameter. Very suitable for the rock garden. He wants warm and dry positions.
Potentilla atrosanguinea comes from the Himalayan area. It is a herbaceous perennial, 60 cm high, with leaves similar to that of the strawberry, deeply dentate, dark green. The species has simple, purple-red flowers about 3 cm in diameter. It flowers from June to August. Widely used for the creation of hybrids.
Potentilla nepalensis similar to the previous one, but with more glaucous foliage and more open posture. The flowers are bright red. The stems are very branched.
Potentilla: Other varieties
Silver leaves, rapid expansion, sometimes invasive
Alba golden treasure
Leaves variegated with gold spots
It wants a lot of sun and dry soil
Arc en ciel
Orange yellow, double, long production
Dark green leaves with silver back
He wants sun and drained soil
Leaves similar to those of strawberries
Sunny but fresh terrain
Semi-double flowers, 3 cm in diameter, red with gold border
Neat head, soft lobed leaves.
Cup semi-double, diam. 3 cm, dark red
Sturdy stems and broad leaves
Intense rose, 3 cm diam.
pink sprinkled with yellow, from spring to autumn
Rose all summer
He wants rich, but well-drained soil
Cup intense red
Up to 50 cm
Sunny and well-drained areas
Very large, pure white with a yellow center
Up to 40 cm
Sunny and well-drained areas
Double, light yellow throughout the summer