Astrophytum

Family. Cactaceae.

Motherland. South America.

Description. One of the most popular cacti. Extremely drought-resistant, adapts well to different temperatures, but prefers temperatures above 10°C.

Many collectors will appreciate its unusual appearance, curved spines and large yellow flowers. 

The stem is 6 - 9 cm in diameter, spherical, sometimes becomes ovoid with age, has noticeable ribs formed along the entire length, their number varies from 4 to 8 (usually 5), they are devoid of spines and covered with tufts of silvery hairs. In summer, daisy-like flowers appear on the top of the cactus - large - about 6 cm in diameter, light yellow with a reddish center, after flowering, after about 2 weeks, red fruits with black seeds appear, which sprout quite easily.

Height. 15 - 100 cm, grows slowly.

 

Caring at home

Reproduction - growing from seeds 

Since Astrophytum very rarely forms lateral shoots that could be used for propagation, these cacti are much more often propagated by seeds.

Seed germination depends on the degree of maturity at the time of collection and the freshness of the seeds. After 2 years from collection, seed germination decreases significantly.

Seeds are sown in late February - early March, and in the presence of good artificial lighting - at any time of the year. Seedlings are kept at a temperature of 21 ° C - 26.6 ° C.

As a pre-sowing preparation, the planting material is soaked in warm water with the addition of several crystals of potassium permanganate for half an hour. Drainage and porous soil consisting of 2/3 river sand, a small amount of peat and crushed charcoal are placed in a seedling container with a lid.

The surface of the substrate is slightly moistened with a spray bottle. Astrophytum seeds are placed on wet sand with a toothpick. Sprinkle the seedlings with a thin layer of sand (about 2-3 mm) on top and cover with a lid.

Leave the container in a well-lit place, but away from direct sunlight. Air the plants daily by lifting the lid and wiping off the condensation.

The first shoots may appear in 5-15 days - at this point, remove the cover completely and water the plants through the tray with water at room temperature or higher.

As they grow, young cacti are pricked out into separate pots or cups. Astrophytums develop for a very long time, and about 6-10 months can pass from sowing to harvest.

The first buds are formed in plants grown from seeds at the age of 6-7 years.

How to care 

This cactus is popular as a houseplant. The plant will bloom at approximately 3 or more years of age. The dormant period in winter stimulates active growth and flowering, during which time the cactus should be watered less and the temperature reduced to approximately 13 ° C.  Withered flowers can be removed from the surface of the cactus by simply slightly pulling the buds upward.

Flowering time 

During the summer, the cactus can be decorated with large buds with silky thin petals. A cool, dry dormant period is important for flowering to occur.

The flowers - single or double - can remain wide open and attractive for as long as 1 day. During flowering, plants can emit a pleasant aroma. 

Diseases and pests 

The cactus does not bloom if there is insufficient light or lack of a cool dormant period.

Rotting occurs when waterlogging and stagnation of water occur, especially in the cold season.

Among the pests that can attack plants are insects such as mealybugs, rootbugs, and scale insects.

Soil for astrophytum 

The best soil for cacti is one consisting of perlite, gravel chips, zeolite, a small amount of peat and compost, ready-made mixtures for cacti. 

It is advisable to sprinkle small pebbles about 2 - 3 cm high on top of the soil for better drainage - it will remove moisture after watering from the root collar.

To protect against rot, you can add a little crushed charcoal to the substrate. At the bottom of the pot there should be a drainage layer made of broken bricks, clay shards or expanded clay - the height of such a layer can reach up to a third of the height of the pot.

The finished soil mixture should have a slightly acidic or neutral pH level.

Transplant 

Young plants (up to 3 - 4 years old) every year in the spring as they grow into a larger pot. Adults need to be replanted every 3 to 4 years. 

Cacti grow slowly and do not require large amounts of nutrients; they are replanted only because the pot has become too crowded. This cactus has rather sharp thorns; you should take care to protect your hands when working with it.

A signal to replant astrophytum can be the fact that the stem has become wider than the walls of the pot.

The flower is removed from the old soil, shaken off the remnants of the old substrate.  The root system is inspected and, if necessary, rotten and old roots are cut off. The cut areas are treated with brilliant green or charcoal powder for drying and disinfection.  Such specimens are left to dry in the open air for 2–4 days.

Prepare new flower pots with large drainage holes and place a moisture-wicking layer on the bottom. Fill the containers with soil for cacti and place a flower with straightened roots in the center of the pot. Gradually sprinkle the cactus with earth on all sides and shake the pot slightly so that the soil settles down tightly enough.

After transplantation, the cactus should be at the same depth. as in the previous pot, and when replanting the size of the pot is increased by only 2 - 3 cm in diameter. Planting immediately in large containers will lead to the appearance of rot, since a large amount of soil will retain water after watering. 

You should not water the flower immediately - leave it for 5-7 days in a well-lit place without direct sunlight. The plants will have enough moisture in the fresh substrate.

Such cacti should also not be fed for 3-4 months - contact with mineral fertilizers on damaged and possibly damaged roots can cause a chemical burn.

Containment temperature

Temperatures in the range of 15 - 21 ° C from spring to autumn are considered optimal for growing cacti at home; wintering of cacti should take place in a cool place - at a temperature of 10 - 12 ° C.  This cactus will tolerate the strongest summer heat without any problems.

In the warm season, take pots with plants to an open space - a veranda, loggia or balcony, protecting them from rain moisture. In such conditions, plants will be additionally provided with a daily temperature difference.

The winter dormant period is necessary for the formation of buds; also in the winter months, plants often experience a lack of light, and the cool temperature will slow down development and the cactus will not become elongated and thin.

You should not suddenly change the temperature background - plants are accustomed to all changes gradually - over 10 - 12 days.

Watering astrophytum 

The best time to water the plant is when the soil becomes dry from spring to late fall. In winter, keep it almost dry, just so that the stem does not wrinkle.   Always water the plants abundantly, but between waterings allow the substrate in the pot to dry out to a third or even half its depth.

For irrigation, use well-settled water at room temperature. Excess moisture that appears in the tray after watering is drained after a few minutes, preventing the cactus’s measles system from being in the water.

Experienced cactus growers can determine the need for watering at a given time by the depth of the plant's ribs - a cactus that is overfilled with water becomes flatter, while with insufficient watering the ribs will become clearer and deeper.

Light

Desert cacti love sun and will grow well if you provide plenty of sunlight.  The location of the astrophytum should be such that the plants receive at least 3 to 4 hours of direct sunlight daily.

Windows facing south-east or south-west are suitable for plants. In the winter months, at lower temperatures, artificial additional lighting will not be needed. In summer, direct sunlight should not be allowed to hit the cactus body during the daytime.

Fertilizer 

Astrophytum is fed only during the growing season once a month with fertilizer for cacti with a low nitrogen content and a sufficiently high potassium content.  Fertilizers can be diluted to half the dose recommended on the package and applied immediately after watering into moist soil.

If these conditions are met, even a fairly concentrated solution will not harm the plants. In the autumn-winter period, fertilizing is not carried out, resuming it only in the spring.

Spraying

There are no special requirements, it tolerates dry heated rooms well.  In the autumn and winter, the air around the plant should be dry - increased atmospheric humidity at this time will quickly cause rotting. Astrophytum will appreciate staying in well-ventilated rooms without cold drafts.

Purpose

This is a slow growing plant suitable for a cactus garden or group planting in a shallow container filled with gravel. 

Note, interesting facts

These are easy-to-cultivate cacti and are perfect for beginners; special attention when growing them should only be paid to the need for a dormant period.   The scientific name of the flower sounds very poetic in translation - “astro” - star and “phytum” - plant.

Perhaps this name is due to the fact that from above some astrophytums resemble starfish. Astrophytum is also called the “bishop’s miter” for the external resemblance of the flower to this priestly headdress.

Varieties of astrophytum:

Astrophytum myriostigma

          Single-growing cacti with spherical green stems covered with silver specks. Often with age, the stems take on a cylindrical shape. Ribs from 3 to 5 - they are vertical or slightly twisted, widely spaced and well defined. There are no spines. The flowers are yellow, funnel-shaped, and appear at the top of the stem. 

Astrophytum ornatum

           Very variable in appearance - the stems can have a different number of ribs and vary in shade from plant to plant - some are green, while others are densely covered with light specks. The fastest growing of the astrophytums. The spines are strong, short, straight, sparse.  The flowers are lemon yellow, 7 - 12 cm in diameter. 

Astrophytum capricorne

         A. capricornus is also very variable - some cacti have very long and curled spines, while other specimens exhibit a complete absence of spines. The number and size of hairy specks characteristic of astrophytums vary greatly. The flowers are orange-yellow, funnel - shaped.