The humidity that warm soils and rain creates will see a rise in mildew and associated fungal diseases, but a spray of PestOil or Bug Oil provides cheap and effective control over a wide range of smooth leaved plants. Do not however spray it at the recommended rate for roses of 30 ml per litre of water, onto grey or woolly leaved plants, or they will drop their leaves.

The quince is a most robust tree in this climate and used as a rootstock onto which many pears are grafted. As a fruiting tree it is at its best when grown very hard without much attention. If you prune it at all expect it to send out hundreds of basal shoots, which if you want any fruit at all, need to be removed. As for the flowering quince you leave those as it proves a smaller more compact plant.

You may have planted some Asiatic Liliums last spring, since they were readily available leading up to Christmas but did you know that right now is the time to divide them. They have a very short dormancy, for a Lilium, but make sure you don’t divide them into too small a clump. A first year clump may have only 6 segments, so just split it in half and replant. They will come into growth immediately, even if they die down in a few months’ time.

Similarly with Alstroemerias, they really don’t have a dormant period unless you garden in a really cold aspect. That’s why they are supplied by the Victorian bulb merchants in March not June. They must be planted immediately and if you aim to divide a clump, now is the ideal time. Feed them immediately with superphosphate or complete ‘D’, then when their growth stalls in mid winter pluck the stems back to the ground, so they are forced to throw new growths in spring. That way they flower better.

Doug in Elizabeth has a Grevillea ‘Flora Mason’ (Grevillea hybrid G. pinaster X G. olivacea), that has it’s leading tips turning yellow. Curious, as this hybrid is quite resistant to our alkaline soil and so it’s unlikely to be lime-induced chlorosis. Doug also mentions that he’s mulched heavily. For starters grevilleas and all proteaceous plants cannot tolerate soft mulch under their canopy and secondly that mulch has probably caused a nitrogen draw down in their root zone, so best remove it altogether Doug and pull back on the watering, that you will anyhow due to the recent rain.

I’m frequently asked how to eradicate nematodes from local vegetable gardens, where they ravage brassicas and a wide range of other crops. They are tiny worm-like creatures in the soil that lance the roots of vegies and reduce crop yields markedly. The telltale symptoms are vegies failing to thrive and upon digging the plants out you can detect swollen nodes on the roots.

While some organic texts claim that planting marigolds will provide an allelopathic leachate into the soil that will control them, research in India over the past 25 years, has shown that only the perennial marigold is in the ground long enough for that leachate to work. The perennial marigold (Tagetes lemmonii) is not that common in Adelaide, so finding it is your first challenge.

The most common and effective control is to use the granular form of Nemacure, spread at the recommended rate. The container it comes in has a peppershaker lid from which you are supposed to dispense the measured dose. It is totally useless and the only way to get the required amount is to remove the lid and measure out the quantity required per square metre. It works but it is expensive. If you know of an organic cure that works I’d love to hear it.

Divide Asiatic Liliums now as they have a very short dormancy if at all in some areas, but make sure you don’t divide them into too small a clump. A first year clump may have only 6 segments, so just split it in half and replant. They will come into growth immediately, even if they die down in a few months’ time.

Similarly with Alstroemerias, they really don’t have a dormant period unless you garden in a really cold aspect. That’s why they are supplied by the Victorian bulb merchants in March not June. They must be planted immediately and if you aim to divide a clump, now is the ideal time. Feed them immediately with superphosphate or complete ‘D’, then when their growth stalls in mid winter pluck the stems back to the ground, so they are forced to throw new growths in spring. That way they flower better.

I was asked recently about pruning an early flowering and fruiting mulberry. Of course if you prune a deciduous mulberry when they are dormant in winter, you have removed most of that year’s crop, so they are best pruned in November after the crop has been harvested. This is termed summer pruning and can be done to flowering stone fruits as well as newly planted stone fruits that you are trying to shape, if they start making strong tip growth.