Many gardeners are familiar with the experience of lifting the lid off a compost bin and seeing a cloud of small flies rise into the air in front of them. These little flies are vinegar flies or drosophila, and the reason why they’re found in […]
Citrus vein enation (CVEV), also known as woody gall, is a viral disease which affects various lemon and lime trees and citrus rootstocks. This disease is caused by the CVE virus, a luteovirus which is transmitted by aphids, including the black citrus aphid (Toxoptera citricidus), […]
Tomatoes grow well during warmer weather, and that is expected since they are subtropical plants native to western South America and Central America. In cool to temperate climates tomatoes are grown as annuals, since they start to decline as temperatures drop in late autumn to […]
White leaf spot is a fungal disease of cruciferous vegetables (brassicas) caused by the pathogen Mycosphaerella capsellae, which is also known as Pseudocercosporella capsellae. The distribution of this disease pathogen is worldwide, it can be found in many countries with temperate climates, where brassicas are […]
Nutrient imbalances and deficiencies can adversely affect the quality of citrus fruit. Excess nitrogen combined with low phosphorus will cause citrus fruit to be misshapen, with thick peel, a coarse and roughly textured rind, coarse pulpy flesh without much juice, and an open centre. The […]
Aloe vera is a hardy, succulent, semi-tropical plant native to North Africa and the SW Arabian Peninsula, which can tolerate quite harsh conditions. It will grow in poor soils in hot, dry sunny locations with very little water, but can also tolerate dappled sun or […]
Queensland fruit fly or Qfly (Bactrocera tryoni) is one of the most damaging pests of fruit and vegetables in Australia. This insect is native to eastern Queensland and north-eastern New South Wales, but has extended its range due to transport of infected fruit, the planting […]
Winter is the traditional time to prune and spray deciduous fruit trees and vines. Spraying is carried out at this time to eliminate pests and diseases which can overwinter and emerge in spring. Two separate treatments are usually employed in winter. Oil sprays are often […]
The problem of garden pest control is as old as agriculture itself, which started when humanity first cultivated plants for food more than ten thousand years ago. Modern conventional pest control methods often use chemical controls as the first option, and usually ignore the real […]
Is your citrus tree dropping its fruit before they reach full size, or even worse, dropping the flowers before fruit even begin to form? This problem can happen to oranges, lemons, lime, grapefruit, mandarins and all other citrus. Trees photosynthesise to produce carbohydrates such as […]
Sun scald is not a disease, but damage caused to apples and many other fruit, caused by high temperatures and strong sunlight in summer. Typically, sun scald damage appear on sun-exposed side, which is usually towards the direction of the midday to afternoon sun. The […]
If leaves are yellowing on a citrus tree, it may be a sign of nutrient deficiency, but it may not be, depending on which leaves are yellowing. Older leaves yellowing are quite normal as long as it’s only happening to a very small number of […]
Why do apparently healthy looking citrus trees suddenly start deteriorating in a matter of days, with leaves curling then dropping, branches dying back, eventually resulting in the loss of the tree? There are several causes, often caused by common gardening mistakes, which are easy to […]
Glue-banding of tree trunks is an effective technique for controlling various pests of fruit trees. A waterproof band covered in horticultural glue, an aggressive long-lasting adhesive, is wrapped around the trunk of the tree to create a sticky barrier which prevents climbing insects from making […]
Crown gall is a bacterial disease caused by Agrobacterium tumefaciens (syn. Rhizobium radiobacter), which produces tumour-like swellings on the bark of trees and plants. It can infect a wide range of dicotyledonous (broad-leaved) plants, particularly members of the Rosaceae (rose) family such as roses, raspberries, […]
If you’ve ever been digging in the garden and discovered plump, pale coloured grubs beneath the soil that curl up into a “C” shape when disturbed, these are Curl Grubs. Curl grubs are the larvae of various species of cockchafers or scarab beetles (family Scarabaeidae). […]
Various cultivars of Navel and Valencia oranges, mandarins and mandarin hybrids are prone to fruit splitting, a pre-harvest physiological rind disorder. Gardeners often wonder if this phenomenon is caused by a nutrient deficiency. Actually, there’s another cause, but plant nutrition can play a part in […]
Apple tree branches covered in patches of white, woolly fuzz? What you’re seeing is a woolly aphid infestation. These pests can be controlled by spraying a few applications of horticultural oil spray (preferably a natural oil-based product rather than a petroleum oil based one) 7 […]
One of the most common nutrient deficiencies seen on citrus is the yellowing of the leaf with dark green veins. Citrus are heavy feeders and are prone to nutrient deficiencies in autumn when they’re fruiting heavily and maturing their fruit, and magnesium deficiency is a […]
Are your citrus leaves turning green with yellow veins in winter? When gardeners see this colour change in their citrus leaves, they often wonder if this is due to a nutrient deficiency, and if so, what they can do to fix it. Leaf Chlorosis The […]
