CULTURE HINTS
(O PĚSTOVÁNÍ)
THE CARE AND PROPAGATION OF CACTI
(GENERAL INFORMATION)
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POZNÁMKY K PĚSTOVÁNÍ RODU ECHINOFOSSULOCACTUS
V
THE CARE AND PROPAGATION OF CACTI
(GENERAL INFORMATION)
Cacti are among the most fascinating groups of indoor plants. Often described as arid
desert plants, they also are found in forests and on prairies.
Watering
Watering properly is one of the most important factors in cactus culture. Soil mixture,
containers, drainage, temperature, size of plant and type of plant all influence water
use, so no absolute schedule can be given for watering.
Careful observation is the best way to determine a plant's water needs. During the
active growing season (spring and summer), water when the top 1/2 inch of soil feels dry
to the finger.
The soil should be thoroughly wetted at each watering, and allowed to dry before water
is added again.
Dormant cacti need less moisture. A light watering every few weeks is sufficient. Do
not soak the soil during the dormant period.
Soils
Good drainage is essential in any soil mix, yet the soil mix also must have moisture
retention properties, along with adequate nutrients. A general growing medium for arid
species of cacti consists of 1/3 peat moss, 1/3 garden soil and 1/3 sharp (builders')
sand. Equal parts sand and a good house plant soil mix also will do.
Many modifications of these mixes can be used. Tropical type cacti require more organic
matter in the mix. Incorporating some pea-sized gravel in the mix improves drainage.
Cacti should be repotted as needed, rather than on a regular schedule. Repot if the
cactus plant is within 1/4 inch of the container wall or edge of the soil ball. Repot into
a container only slightly larger than the present one. Repotting into a container too
large may lead to a tendency to overwater.
Set the plant in the new container at the same level it was originally growing and fill
around it with damp soil. Wait several days before watering so damaged roots will have
time to heal.
Fertilizer
Like other types of house plants, cacti need fertilizer, but in smaller amounts. From
spring to fall they can be fertilized every two to three months with a low nitrogen
fertilizer such as 5-10-10. Excess nitrogen can cause succulent growth, leading to insect,
disease and other problems. Time-released fertilizers also can be used, but need only be
applied once in the spring.
Do not fertilize newly repotted plants, unrooted plants, or plants going through a
dormancy period.
Light
Most arid species of cacti require bright sunlight to grow well. Windows facing south
provide the most sunlight, while windows facing east and west usually offer some direct
sun for at least part of the day.
In some homes, artificial light may be necessary to supplement natural light.
Temperature
Proper temperatures for raising cacti vary with the season. Arid cacti plants tolerate
temperatures of 90-100°F during the active growing season. They can be placed outdoors in
late spring, but for several weeks may need to be shaded during the hottest part of the
day until they adjust to the temperatures and higher light intensities. In the early fall
it is necessary to bring them indoors before a frost.
Dormant cactus plants do best at temperatures from 45-55°F. The cooler temperatures
develop sturdier plants and encourage the formation of flower buds. Cool winter
temperatures are not a necessity for cactus plants, but these conditions approach the
environment in which cacti normally grow.
Convenience often will decide the temperature at which cacti plants are maintained.
Propagation
Cacti usually are propagated by seeds, cuttings, or offsets. Some species are more
difficult to propagate than others.
Cuttings are pieces of cactus stem without roots. Allow cuttings to dry for a few days
before placing in a rooting medium. This permits the cut surface to heal, or callus. The
callus helps prevent rotting when the cutting is placed in the rooting material.
Place cuttings in a rooting medium of equal parts peat moss and sharp sand. Place in a
sunny location and water occasionally. Too much water should be avoided.
Pot the cutting after roots have formed.
Offsets are sections found at the base of the plant. Rooted offsets can be separated
from the parent plant and potted immediately. Unrooted offsets should be treated similarly
to cuttings.
Most species of cacti may be propagated from seeds. A simple way of germinating cactus
seed is to spread the seed on the surface of moist, sterilized soil and barely cover with
sand. Place the container in a plastic bag and seal. Some types of seed will germinate in
a few days while some may require several months.
Remove the plastic bag when seeds have germinated. Transplant the seedlings after a
vigorous root system has formed. This will take several months.
Grafting, the union of two or more different plants, produces unusual growth forms and
provides a decay-resistant stock for certain kinds of cacti. Grafting also can save a
plant with a rotted stem or root system.
The grafted plant consists of two parts, the stock and the scion. The stock, or
understock, is the bottom part of the plant growing on its own roots; the scion is a
portion of another plant joined to the top of the stock. The stock and scion must be
botanically compatible to have a successful graft.
Select the cacti to be used as the stock and scion and make appropriate cuts with a
sharp knife or razor blade. The grafting should be done when the stock is actively
growing. It is very important to make sure that the surfaces to be joined on the stock and
scion are clean, fit closely together and do not dry out before they are placed together.
Hold the scion in place with string or rubber bands or by running several wooden or
plastic toothpicks through the graft union. Keep the plant in a moist, warm place so the
union will not dry out and force the graft apart.
Usually it takes about two weeks for the stock and scion to unite. Then the bindings
can be removed.
There will be a shrinking and discoloration of the union if the graft has failed. In
that case repeat the process, making sure the graft union does not dry out.
Diseases and Pests
The major diseases of cacti are root and/or stem rots. Excessive watering should be
avoided to prevent these rots. Make sure there is good air circulation between plants.
Insect and related pests on cacti include aphids, red spider mites and mealy bugs. Make
sure newly purchased plants are free of pests before they are added to your plant
collection.
If insects or mites do become established on your plants, consider using a registered
insecticide or miticide to rid the plants of these pests.
POZNÁMKY K PĚSTOVÁNÍ RODU ECHINOFOSSULOCACTUS
Všeobecné rady
Pěstovat v minirální, propustné půdě. V období růstu plné slunce (ale pozor na
přílišný úpal - vysoké teploty ve skleníku), v zimě chladno a sucho. Brzké a
bohaté kvetení je podpořeno dostatkem světla v zimním období. Nesnáší vápenitou
zem. Ve vegetačním období by substrát neměl příliš přeschnout.
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