Caring for your Aloes

GENERAL
Most people (and birds) enjoy the winter flowering aloes because there is little else to brighten the landscape at that time of year. Winter is also the natural flowering season for the larger varieties/cultivars. With the right combination of aloe hybrid cultivars available from Sunbird Aloes it is possible to have flowers for most of the year. Like any other garden plant, aloe cultivars enjoy a bit of pampering –  plant in a sunny spot in soil with lots of compost and good drainage. Water during dry spells in the growing season (summer). A top dressing of composted manure or fertiliser during the growing season will result in a stunning flower display lasting through all of the winter months.

FROST TOLERANCE
Cold is the unpredictable factor when growing aloe hybrids. Often a few meters’ difference in location can either mean frost damage or none at all. All Sunbird Aloes are born and bred on the frosty Gauteng Highveld just North of Johannesburg, and all the medium and large cultivars are grown in the open where light morning frost in winter  is a common occurrence. For this reason most of the cultivars are given a rating of “medium” when it comes to frost tolerance. Heavier frost can be problematic, particularly for flowers. Given low enough temperatures, even plants will succumb. They are, after all, succulents with moisture filled foliage.

As a general rule, the smaller the plant, the greater the likelihood of cold damage. For this reason  the small cultivars grown by Sunbird Aloes are given a frost tolerance rating of “low”, planted in nursery bags or pots and kept in open plant houses where they can be covered to protect them from direct frost in winter. These plant houses are not heated, however, and are often covered in an icy sheet. Some of the smaller hybrids can probably deal with cold as well as the larger plants, but this would be best established by the gardener him/herself as it would depend on the planting site.

WATER
All the Sunbird Aloes are drought tolerant. Even though they can go through long periods without water (you can go on holiday without worrying that everything will die) they are garden plants that will appreciate watering during dry spells in summer, and will flower at their best when given a little composted manure or organic fertiliser as a top dressing when rain can take the nutrients into the soil. Early- to midsummer would be the best time for feeding.

Plants in containers should be given enough water to maintain some moisture in the container, but never when moisture can be seen or detected by a little finger digging.

How much water do aloe hybrids need? Just for survival, actually, very little indeed. The Sunbird Aloes rockery has gone through periods of up to 6 months (normally in the winter) without a drop of water, without serious repercussions. Of course these are well established garden plants with quite a bit of reserve moisture carried in the leaves. As a general rule, the smaller the hybrid, the more often it will require watering. The very small pot plant sized aloes need some moisture where the roots are concentrated at all times. Watering periods will differ depending on the growing medium, the size and the location of the container, but they will probably need water at least once a week. As with many potted plants, over watering is always a bigger problem than too little water.

Newly planted aloes need more regular watering for a few months until such time as they are well established and the soil has settled. For aloes bought in nursery bags it would mean approximately 4 weeks of ensuring that the soil does not dry out completely. For open root plants (larger specimens grown in open soil are dug out and sold with exposed roots) there is a waiting period of four weeks before any watering takes place, after that the same as for plants in bags.

A big benefit of having aloe hybrids in the garden is that it is the one area where expensive sprinkler systems are not necessary. In times of severe drought as some areas are seeing now, a thorough watering once every three weeks for established plants will keep them going quite happily. This is simply done with a hose pipe and garden sprinkler. You can leave the plants unattended for weeks on end when you are out of town or on vacation, and still expect to see a flower display worthy of a tourist attraction come winter time.

CONTAINERS
Sunbird Aloes can be grown successfully in containers, provided cognizance is taken of the ultimate size of the plant. They require a well drained sandy soil with lots of well composted material mixed in, and as much sun as you can provide. As a general guideline an aloe can be allowed to grow to twice the size of the container before it needs to be given more space. If the plant is expected to maintain its flowering performance it is advisable to replace the potting medium every 2 to 3 years.

PESTS AND DISEASES.

GALL MITE (ALOE CANCER) The organism that causes the abnormal growths cannot be seen with the naked eye, which makes it difficult to control before it has infiltrated your plant(s). Very often the first sign of gall mite is a new inflorescence that emerges from the plants all crooked and bent. Upon closer inspection you may see the first signs of frilly growth on the peduncle which develops into unsightly galls on the flower raceme as it matures. The same galls may also start as an irregular growth on the base of some of the older leaves, often where an earlier inflorescence has dried. The best treatment is to cut away the affected tissue with a sharp blade (e.g. carpet knife) and treat the cut with a strong solution of Aphicide or other systemic insecticide. The whole plant can be sprayed with the recommended solution of the same insecticide a day or so later. Be careful not to cut during wet weather. The gall mite travels through the air and also to other aloes that are touching an infected plant, so it is advisable to keep an eye open for signs of infection. An alternative treatment is under development – watch this space! 

The new treatment for gall mite, although still experimental, is producing such good results that it can now be revealed  - a first for Sunbird Aloes! The plant to be treated must be dry and kept dry for the duration of the treatment. It involves simply painting only the abnormal growth with formalin (formaldehyde), readily available from most large chemists. Use it sparingly on a small brush and prevent dripping and runoff, and take care not to get any on your hands. Repeat the treatment after 3 days. Inspect the area again after another 3 days and only repeat if there are still signs of green growth. Large galls should be cut away first and signs of regrowth treated as explained. It may be better to cut away the frilly growths on an inflorescence and not to use a strong chemical like formalin near buds or flowers. Please let us know your results.

SNOUT BEETLE  This is aloe enemy number one, so quick and decisive action is required whenever they are noticed. The beetle itself is about 1,2 cm long (varies) and invariably aims at the centre of the aloe plant where it can wedge itself between the leaves to insert its proboscis. This is done to drink the leaf sap (like with a straw) and leaves a telltale dark spot that dries into a pea-sized dry spot with a puncture mark in the middle. Once the beetles have mated, the eggs are deposited at the base of the leaf from where the newly hatched larvae bore straight into the stem where they spend the remainder of their life cycle. The rot and destruction caused by the larvae is what eventually kills the aloe. Physically removing and killing the beetles, or a sprinkle of insecticidal powder should take care of the problem, provided they have not been there too long. Regular inspection of your plants is necessary where snout beetles occur.

APHIDS AND MEALIE BUGS  These pests over winter in protected areas on a variety of plants, and become active as soon as the worst winter cold has passed or even during mild winter weather. They will aim for the very centre of the aloe plant and may require some close scrutiny to detect. The presence of ants on the aloe is often the first sign of aphid infestation. When they have been left unhindered for a few weeks, the aloe reacts by  closing the centre leaves in an effort to protect the damaged tissue. This suits the baddies perfectly because it means more hiding place for them. If left untreated aphids can cause severe damage to the new growth, sometimes with rot setting in resulting in the loss of a plant. A variety of garden insecticide sprays and powders are effective in controlling this pest, as are some of the organic insecticides. When spraying aloes it is always wise to use a spreading/sticking agent and to apply a very fine spray if possible. Remember to pull the centre leaves apart where they seem to be stuck together, before applying insecticide.  

WHITE SCALE  This looks like white dust gradually covering  more and more of the leaf upper and lower surface. They are stationary insects that are easy to kill, but they tend to remain where they are, creating the impression that the insecticide has had no effect on them. Use any contact insecticide to spray with, or if you prefer not to use poisons, a soapy solution of laundry cake soap (real soap) will also do the trick, provided it is not washed off by rain.

RUST  This is a very aggressive fungus that attaches itself to any part of the leaf surface. When established, it starts showing as a yellow spot below the leaf skin, gradually growing until it is a small coin size. The leaf skin then perforates, exposing the rust coloured spores that look like reddish brown powder. The wind will distribute the spores over a wide area, where they quickly establish and grow. The best treatment is to cut heavily infected leaves and dispose in a closed plastic bag – do not leave on the compost heap. Un-perforated spots may be treated by breaking the leaf skin and applying a drop of formalin/formaldehyde. Take care to avoid run-off and do not spill any in the centre of the plant. The formalin leaves a dead spot on the leaf but is a very effective treatment. General fungicides have no effect once the fungus is established.

BLACK LEAF SPOT  This may be caused by a variety of fungal or bacterial infections, and is more likely when plants are under stress due to excessive moisture or high temperatures combined with high humidity. Some aloes have a genetic susceptibility, and often a few spots is unavoidable. This is no cause for concern as it does not affect the plant’s health or flowering. If the spots are really unsightly  (e.g. covering more than 10% of the leaf surface) spraying with fungicide may clean up the new growth.