The Crassula ‘Tom Thumb’ or Crassula` Klein Duimpje´ is a small herbaceous and perennial succulent plant of the Crassulaceae family obtained by crossing Crassula rupestris marnieriana with Crassula rupestris rupestris.
The morphology of this plant is very similar to Crassula perforata, but in smaller dimensions.
Sometimes it is confused with a variety of this species.
It is a very commercialized plant worldwide as a collection plant since, in addition to being beautiful, it is very easy to grow.
This plant is characterized by developing erect or slightly decumbent branched and very thin cylindrical stems that fail to exceed 15 cm in height (rarely reaching more than 20 cm).
On the stems are arranged pairs of opposite leaves (the pairs very close together) very fleshy and triangular.
The sheets merged into the base.
The coloration of the foliage is light green with numerous spots of reddish-violet color and the dark +/- margins depending on the light intensity that the plant receives.
The flowers are arranged numerous in inflorescences that arise at the apex of the stems.
All flowers have 5 white triangular petals that unfold slightly backward.
Tips to take care of the Crassula ‘Tom Thumb’
It is an ideal plant for beginners requesting the following care:
Illumination
It requires a lot of lighting for optimal growth and formation of new branches on the stems.
It is advisable to expose to the sun in the early hours of the morning and late in the afternoon.
Protect from the intense sun of noon.
Temperatures
The Crassula ‘Tom Thumb’ prefers a cool climate where summer temperatures do not exceed 32ºC nor in winter they decrease from 8ºC.
Never expose to frost.
Substratum
It is recommended to grow in soils slightly rich in organic matter and with excellent permeability.
It does not tolerate growing in compact and flooded substrates.
Watering
Water after the surface of the substrate is slightly dry.
The main objective is to water enough to keep some moisture in the soil, but not in excess.
In winter it is recommended that the substrate dry completely between waterings to avoid possible rot problems.
Plagues and diseases
Frequently attacked by mealybugs that are housed between pairs of leaves.
Also, the tender ends of growing stems can be attacked by mollusks.
Propagation
To multiply the Crassula ‘Tom Thumb’ is Very simple through cuttings of stems +/- 8 cm long.
To increase the chances of rooting, rooting hormones can be applied to the cut area.
Conclusion
Crassula ‘Tom Thumb’ is the perfect succulent for miniature gardens, terrariums.
It grows up quickly and then begins to trail.
Many little clusters of white flowers bloom in the Spring.
Even though regarded as a common crassula, that does not prevent it from being one of the most exquisite.
It originates from a chance cross between Crassula rupestris (ssp. rupestris) and Crassula rupestris ssp. marnieriana and was found by W. J. Ruysch, The Netherlands.
When it flowers the plant is is only 10-12 cm in height, but grows well and should prove an interesting and worthwhile addition to any crassula collection.
Produces tiny heads of many small star-shaped white flowers in winter if they are given proper conditions of temperature.
There is also a variegated mutant called Crassula ‘Pastel’.