My cacti plants have been neglected this year. And they love
it. I did repot them at the beginning of the season, then put them on a shelf
in the tunnel and promptly forgot about them. Their only water source was
condensation and the odd over spray from the tomatoes. A few of them are
flowering as well which is always pleasing to see.
Cacti
Cacti are classic examples of plants that have evolved to
grow in environments where water is scarce for large parts of the year. Most of
the varieties don’t have leaves but swollen stems. These stems contain
water-storage tissues and a thick waterproof skin, usually covered with a waxy
layer to help prevent water loss. Cacti
can have extensive root systems, spreading just below the soil surface, so that
they can absorb even the relatively small amounts of water that moisten the
soil surface during light showers of rain, which isn’t much help to them in my
small pots. To help them store water in the occasional time I give them water,
the fluted stems with ribs expand and contract without damage to the surface
tissues.
Cacti also have evolved to use the stems as the main method
of photosynthesis rather than using
leaves.
In place of leaves, cacti have areas where spikes come out
(areoles). These are like buds and they are arranged regularly along the ribs
of the stem. They produce spines which help to protect the stems from being
eaten. In some cacti that I have the spines are so dense that they almost
completely obscure the underlying stems, shielding the stems from intense
sunlight and preventing the plant from overheating.
Cacti as Houseplants
Cacti make great houseplants and makes a big impact to a
room.
What to look for when
buying cacti
- Assess the size where the plant will be going. Larger plants generally cost more.
- Check that the cacti are free of mealybug on both the plant itself and the root system. With its woolly white layer of wax, it’s one of the most common pests on cacti and difficult to deal with.
- Spider mite (eight-legged insects that cover the plant in a fine and dense web), aphids, brown scale and scale insects or thrips can also occur.
- Check for damage, and ensure that the roots are in good condition. If the plants have been left in wet soil for an extended period, they may have rotted ‘from the pot’. This can also be caused by fungi and bacteria. The green part, the actual stem, will then feel soft and could be discoloured.
Choice of cacti
Many cacti are sold in mixed trays, particularly the smaller
sizes. The plants I have now came from a job lot on e-bay of bare rooted plants
and was very happy with the quality. I have tried growing the plants from seed
but it takes a long time and is pretty fiddly. I had about fifteen different
types in the bundle.
If you have friends with older cacti you will find they have
small offsets. These can be pulled off and planted up after leaving to dry for
a day or two.
Succulent Euphorbia species closely resemble cacti and are
often placed in the same product group. It’s easy to spot the difference. On
Euphorbia the spikes and thorns grow directly out of the green body of the
plant, whilst on cacti they grow out of the areolae.
Care tips
Cacti are easy to care for. In order to get the plant to
flower successfully every year, it’s best to give it more water in the summer
and less in the winter. This is partly dependent on the species and the size of
the plant.
- Too much water is never good; it’s best to allow the soil to dry out before watering again.
- A cactus appreciates a warm and sunny spot in the summer; it can even go outdoors on a patio or balcony. The position should be cooler and light in the winter. This rest period in the winter helps the cactus to flower in the spring.
- If the plant needs to be repotted, use a fairly impoverished soil. Special cactus soil is available for this.
- Place the plants in a safe place if there are children or pets around.
