With its three petals, the spiderwort is a special eye-catcher in the garden. The tender perennial quickly forms large cluster in fresh and moist locations.
Profile of spiderwort:
Scientific name: Tradescantia
Plant family: spiderwort family (Commelinaceae)
Other names: Indian paint
Sowing time: mid-March indoor, then plant outdoors mid-May, after frosts
Planting time: mid-May, after frosts or alternatively from late September to early October.
Flowering period: May to September
Location: Partial shade, sunny
Soil quality: stony, sandy, loamy, gritty, moderately nutrient-rich to nutrient-rich, humus rich, tolerates lime
These information are for temperate climate!
Use in: flower beds, ground cover plants, ornamental plants, cottage garden, flower garden, terrace garden, potted garden, ornamental garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 6
Bee and insect friendly: Yes
Plant characteristics and classification of spiderwort
Plant order, origin and occurrence of spiderwort
The spiderwort (Tradescantia) comes from the genus Tradescantia,and belongs to the spiderwort family (Commelinaceae). Some spiderwort (e.g. Tradescantia x andersoniana) are, in contrast to many conspecifics of the genus, absolutely hardy. Hardy spiderworts also exist in nature, they grow on nutrient-rich soils in North America as hardy perennials. The plants are semi-perennial to perennial, the rhizome rests in winter. They can be sown in the garden all year round as soon as the ground temperature is around 20 °C / 68 °F.
Characteristics of spiderwort
The spiderwort grows upright and forms large, bushy cluster in a short time. The pond perennial grows to heights and widths of between 20 and 60 centimeters (8 to 24 in). Warning: The spiderwort tends to sprawl.
The grass-like leaves are simple and alternate. They are lanceolate, with entire margins, parallel nerve and slightly meaty.
The spiderwort blooms in striking triple, wheel-shaped flowers that turn blue, violet, pink or white depending on the variety. The delicate flowers only last for half a day, but are constantly replaced by new ones between May and September. This is how the spiderwort blooms for many weeks in summer.
After flowering, Tradescantia forms three-chamber capsule fruits. There are one or two seeds in the chambers that sow themselves very successfully.
Spiderwort – cultivation and care
Spiderworts are able to grow in almost all lighting conditions. The adaptable perennials don’t feel comfortable only in the blazing sun and in full shade. For most outdoor perennials, a partially shaded spot with a few hours of sun in the morning or evening is ideal.
- Outdoor plants: sunny to half-shady
- Indoor plants: bright, without direct midday sun
- Houseplants need temperatures of around 20 °C / 68 °F.all year round
Indoor plants prefer very bright lighting conditions without the direct midday sun. They feel particularly comfortable on an east or west window, or also on the south window behind a curtain.
The garden soil should be humus-rich and nutritious. Good drainage is just as important as the property of the soil to adequately store moisture. The spiderwort prefers a slightly moist soil that is not prone to waterlogging.
- slightly acidic to neutral
- well permeable
The spiderwort is ideal for planting banks of garden ponds and streams, or for planting bushes where the ground is shaded during the noon hours, but otherwise there is sufficient sunlight.
Substrate for potted plants
If the spiderwort is cultivated as a houseplant or in a planter on a balcony or terrace, normal garden soil is generally not the suitable substrate. The plants grow significantly better in a mixture of a large number of organic and mineral components. In this way, the plants remain healthier, will bloom in the long term and are better protected against diseases or pests. In addition to normal humus-rich potting soil, the following components should be included.
- rough texture
- light and sterile
- promotes ventilation
- keeps moisture well
- regulates the soil pH
- consists of rock of volcanic origin
- offers good drainage and ventilation
- very light
- must always be mixed with other media
- as an alternative to perlites
- is more compact than perlite
- holds the water well
- doesn’t offer such good ventilation
- improves drainage
- no water storage capacity
Alternatively, coconut or coarse pieces of bark can improve ventilation. A good soil can be bought in specialist shops, but it can also be made from a mixture of around 60% humus potting soil, 10% coarse sand or grit, 10% perlite or vermiculite and 20% peat moss.
Tradescantia can either be bought as a plant in the garden center or grown from seeds. Pre-cultivated spiderworts are planted in the bed at the earliest after the last frosts in mid-May or alternatively from late September to early October.
If you cultivate the extraordinary spiderwort yourself from seeds, you should sow it about eight weeks before planting out (mid-March). Spring sowing is also best suited for houseplants, because at this time the lighting conditions are ideal for the growing spiderwort.
Planting in the bed
As soon as the temperatures in spring are permanently frost-free, the spiderwort can be planted in the bed or a flower pot. Good soil preparation creates the best conditions for good growth and abundant flowering. Therefore, it makes sense to rake the bed well in advance and remove old roots, weeds and stones.
The plant can be planted directly in humus-rich, well-drained garden soil. Very sandy soils should be enhanced with a good portion of compost or humus-rich potting soil. Heavy substrates become more permeable with sand or grit.
- planting distance: half the height
- depending on the variety, between 10 and 30 cm (4 and 12 in)
- in the case of heavy soils, insert a drainage layer made of gravel or grit
Press the earth lightly and water the spiderwort thoroughly. If the plants regularly receive irrigation water in the early days, new roots quickly form. The bushy growing plants tend to grow rapidly, covering the whole area, so initial gaps close in a short time. So that the God’s eye does not overgrow the bed after a few years, it should be cut off regularly or a root barrier installed right at the beginning.
Planting in a pot
All spiderworts can be kept as an indoor plant, but the species that cannot tolerate frost are particularly predestined and therefore need warm temperatures all year round. The plants can also spend a few days or weeks in a sheltered place outdoors in warm weather in summer.
All planters must be equipped with a drainage hole so that excessive water can run off. First put a layer of grit or expanded clay in the pot for good drainage. Use only high-quality plant substrate or your own substrate mixtures to offer the plant the best conditions for a good start.
Spiderworts like it a little bit damp, but not wet. So water regularly, especially those plant that grow in pots. A quick thumb test can tell if the substrate still contains enough moisture. If the upper layer of earth has already dried out, the plant needs water again. Excess watering water must be removed from the planter or saucer after a few minutes so that it does not become waterlogged.
Outdoor plants only need additional water in longer dry periods. A layer of mulch protects the soil from drying out too quickly.
Succulent species such as Tradescantia navicularis or Tradescantia sillamontana are watered a little more sparingly, but must also never dry out for a long time. It is best to water again when the substrate is about half dry.
Bedding plants can be supplied with nutrients for the entire season by mixing in compost in the spring. Alternatively, it is also possible to add some horn shavings into the earth. Container plants or houseplants are fertilized every four weeks in the growth period between April and August with a little liquid fertilizer for flowering plants over the irrigation water.
Spiderworts that grow in the house do not need to be cut. However, the plant can tolerate cuts all year round if it has grown too large or grows unevenly. However, more than a third of the shoot length should not be cut off. If the faded is removed regularly, the spiderwort blooms long and persistently.
Garden plants, however, should be cut back radically once a year. If the spiderwort withdraws in autumn and the leaves wither, all above-ground parts can be cut back to about 10 cm (4 in) above ground level. However, this must not happen too early, because after flowering, the perennial initially collects nutrients in the roots so that in spring it has the strength to sprout healthy and vigorous again. So wait until the leaves are withered or dried up before pruning. Plucking the withered flowers also ensures plenty of new flowers.
Spiderworts can be propagated by cuttings or seeds. But, the easiest way is by dividing older perennials.
Since the spiderwort shows vigorous growth, it should be divided about every three years. This rejuvenation not only promotes flowering, but also produces a second plant.
- Time: spring or autumn
- cut the root ball with a spade
- cut off dead roots and plant parts plant both parts again immediately
- mix in some compost
- water well
This method has the decisive advantage that two plants with the same properties are obtained when they are divided. Single-variety propagation is often not possible with self-collected seeds. In addition, the plants are of a very pleasant size.
The Indian paint can be propagated all year round using cuttings. To do this, cut a roughly 10 cm (4 in) long, strong shoot. In the case of outdoor plants, of course, cuttings can only be cut during the growing season.
- Time: all year round (preferably in early summer)
- Remove the leaves on the lower third
- Put 6 to 8 cuttings in a pot
- Substrate: peat moss and sand in equal parts
- Moisten substrate slightly
- set up bright (without direct sun)
If the rooting shows that fresh leaves have sprouted, the cuttings can be separated. From now on, the young plants will be treated and cared for like full-grown spiderworts.
Ripe seeds can be picked and sown. In the case of special breeds (hybrids), however, there is a high probability that the seedlings will no longer show certain properties of the original spiderwort, such as the special flower color. The preculture on the windowsill begins about eight weeks before planting out, i.e. in mid-March.
The seeds of outdoor plants can be sown directly outdoors in autumn or March. Garden spiderworts reproduce reliably on their own by self-sowing, without ever becoming invasive and displacing other plants.
- Date: mid-March (outdoor and pre-cultivation)
- Outdoor also in autumn
- Outdoor: rows of seeds about 15 cm (6 in) apart
- Pre-cultivation pots or indoor greenhouses
- Substrate: growing soil
- Moisten substrate and sprinkle seeds
- Germination time: 10 to 20 days
- Location: bright without direct sun
Diseases and pests
In addition to being easy to care for, the spiderwort – whether cultivated indoors or outdoors – has another pleasant property: it almost never gets diseases. If one excludes care mistakes such as dryness and waterlogging, diseases have almost never been observed in Tradescantia. If varieties with colored leaves lose their color, the plant is placed in a too dark spot.
Usual pests for house plants such as lice or mites occur in rare exceptional cases. In the early stages, however, these can be washed off well with lukewarm water.
Wintering is very easy with the spiderwort.
Houseplants only need to be watered a little more slowly, as the active growth phase ends in September. Fertilization will also cease until spring.
Garden plants remain in the ground and do not need winter protection in protected places, as they usually survive frosts of up to around -20 °C / -4 °F without any problems.
Container plants can either be brought into the house from the beginning of September and overwinter in a warmspot, or overwinter in a protected place outdoors.
- Houseplants: all year round in the apartment, just add fertilizer
- Bedding plants: winter protection is not necessary in protected areas
- Cover all other plants with some brushwood or leaves
- Container plants: place on wood or polystyrene plate, cover the container with fleece
From the end of March or the beginning of April, depending on the weather, the winter protection can be removed. Spiderworts overwintered in the house are slowly getting used to the sun and outside temperatures from the beginning of May. In warm weather, however, they first come outdoors during the day before they are allowed to stay completely outside from mid-March.
Use in the garden
The spiderwort is a beautiful perennial for natural gardens and herbaceous beds as well as for planting pond edges or streams. Good planting partners are grass, lady’s mantle, loosestrife, moor grass or iris.
Tradescantia distinguishes between varieties that need warm locations all year round (houseplants) and species that can be planted as perennials in the garden because they are hardy.
Houseplants (not hardy)
- Tradescantia blossfeldiana: succulent species
- Tradescantia discolor (pupil-leaved spiderwort)
- Tradescantia fluminensis (white flowers)
- Tradescantia navicularis: succulent species
- Tradescantia pallida (red leaf)
- Tradescantia sillamontana: slightly succulent
- Tradescantia zebrina (inchplant or wandering Jew)
Garden plants (hardy)
- Tradescantia bracteata (prairie spiderwort)
- Tradescantia pilosa
- Tradescantia subaspera
- Tradescantia virginia (Virginia spiderwort)