Local gardeners and farmers in their 60s will tell you that their fathers used to sow the first batch of vegetable seeds for early crops in late July. Global warming has become a fact of life in the past two or three generations and the seed-sowing season is being pushed ever later in the year. The downside is obvious, but the upside is that it is still not too late to sow seeds for most herbs and tender leafy vegetables plus many flowering annuals. In a temperate climate these would all be for spring planting, so it can be confusing to think of them as best suited to autumn, winter and early spring in Hong Kong’s sub-tropical conditions.
If you have a garden, you can try sowing a few seeds straight into the ground. Large seeds like Nasturtiums, marigolds, okra, and peas and beans should flourish in large pots, although you need to be wary of hungry ants. Even professionals usually start their seeds in trays or small pots before transplanting them into roomier intermediate or permanent homes. The major advantage is that it is relatively easy to move seedling trays to safety if October brings typhoons or thunderstorms. As seedlings appear, they should be moved gradually into full sun.
In his gardening bible, Growing Your Own Food in Hong Kong, Arthur van Langenberg advises allowing the soil in trays or small pots to dry out a little before transplanting. The relatively dry root ball holds together when the seedling is moved, making the procedure less stressful for the plant. I must admit that I have always done the exact opposite; getting the seedlings really wet so that they can be easily lifted out of the nursery, hopefully without damage to the roots, before moving them to new surroundings. I am convinced of the logic of Arthur’s approach: only time will tell how it works for me.
Hibiscus sabdariffa (rosella) is Hong Kong’s latest “miracle” plant; the go-to for everything. It is popular as an infusion made from the dried calyxes, but with its high vitamin C content, sharp flavour and rich colour, it lends itself to many creative uses in the kitchen. Young shoots and leaves can be used in a curry or to give added colour and sharp flavour to a raw salad. The flowers range from pale pink to ruby red, so they make a very decorative plant. It is generally treated as an annual. Seeds are readily available and it will grow easily from a cutting. It seems to be pest-resistant – maybe caterpillars dislike the sour taste.
In late May I was given some okra seedlings which I transplanted into a rather small flower bed where they thrived, despite all the heavy summer rain, producing beautiful flowers that were closely followed by delicious, tender pods. By early August, however, the formerly healthy plants were targeted by voracious leaf rollers. Morning, noon and night I would find a new batch of tightly rolled leaf edges, each containing a greedy little green caterpillar. Even if you can squash all the invaders, the leaves are sadly disfigured and the insect’s saliva weakens and ultimately destroys the entire plant. The old Latin name of okra, Hibiscus esculentus (now renamed Abelmoschus esculentus for reasons best known only to taxonomists) makes it clear that this edible delicacy is a member of the same family as the showy shrub, whose leaves are equally susceptible to leaf rollers. Okras are annuals and the plants take as much as three months to become productive, but they will continue to put up new flowers and “fruit” as long as the soil temperature remains above 15 degrees. So it is worth taking some trouble to keep the plants healthy.
By mid-August the invasion had reached such a point that I decided to seek professional advice from the Community Growers Group (an offshoot of the Vegetable Marketing Organisation). As the name suggests, CGG is a semi-government organisation, but staff are helpful and they sell organic pesticides too. On their advice I bought a white oil spray that claims to have antifungal properties as well as being able to deal with a wide range of pests. The recommended dilution rate is 1:1000 so that should give a good number of the recommended weekly preventive sprays. I’m already hoping this will be the winter when I can finally beat the caterpillars in the race to grow rocket (arugula) that can go in a salad before the offspring of the Cabbage White butterflies leave nothing but the leaf veins.
Caterpillar infestations apart, all members of the Hibiscus family benefit from similar treatment. Prune the centre of the growing plant to force it to produce side shoots, each of which will bear flowers and fruit. All need plenty of fertiliser with a high level of phosphorous, which boosts growth and helps plants to resist insect attacks.
Unfortunately I don’t think anything from a bottle can help my only large tree, a Moringa oleifera (aka drumstick or horseradish tree). Over the past 30 years this has reached a height of about 10 metres and it produces its long, bean-like fruits for about nine months in an average year. I am the first to admit that it is not the most beautiful tree, but it is highly productive and it obligingly grows where it can readily be harvested from the roof, enabling us to enjoy our curries of freshly harvested “drumsticks” for most of the year. It grows very fast; as much as three metres a year in favourable conditions and it needs to be drastically trimmed from time to time. Now, however, it is starting to look tired and it seems wise to have some understudies in waiting. Fresh dry seeds are easy to germinate, although seedlings are hard to transplant. The usual way of propagation is to insert a piece of cut branch or trunk in the ground and leave it alone. In warm weather it should take within a very short time. In rural Sri Lanka, South India, the Philippines and Malaysia it often serves a dual role as a food supply and as fencing to keep animals away from vegetable plots. Moringa flourishes in many areas of the globe and it does surprisingly well in Hong Kong, although it is rarely cultivated.