Most gardening books tell you that it’s impossible to grow vegies without at least six hours of direct sun daily – maybe true for the UK’s weak rays but, here in hot, sunny Oz, that maxim simply isn’t true. Sure, some vegies fruit less than what market gardeners require, but home gardeners can still harvest a crop to be proud of. Other vegies actually prefer a bit of protection from our blazing summer sun, and there are many ways to manipulate shade and microclimate. Read on for tips I’ve used with great success in my own garden, with its southerly aspect plus fences and trees to the north!
As early readers of my blog will know, the purchase of additional land at the back of our suburban sized block (Relocation) was spurred by the desire for more sun, to grow more fruit trees and vegetables. I had one area of about five square metres that received a maximum of five hours of direct sun in midsummer (less at other times of the year), with the rest of the garden receiving dappled shade, solid shade, or a couple hours of sun in the morning or afternoon. The southerly sloping aspect exacerbated shading to the south of the house, but I was still able to harvest many vegetables and fruits elsewhere.
1. Time of shading: Morning sun versus afternoon sun.
Many vegetables and fruiting plants actually prefer shelter from South Australia’s blazing summer afternoon rays, so shade from trees to the northwest and west of your garden may be an asset for plants like red and white currants, bramblefruit, hazelnuts and other Northern European or understorey varieties. Deciduous trees are even better, because they don’t cast shade in winter.
2. Hours of sun or amount of shade
Don’t be afraid to try vegies even when you have only a few hours of sun a day. Nearly all leafy greens and quickfruiting varieties (I’ve had success with cherry tomatoes in surprisingly shaded spots) will produce a crop as long as you also give them excellent soil, ideal moisture, and a generous fertilising regime. The placement of different tree species in the new area was governed largely by their potential to cast shade, as well as the amount they require (Designing my productive garden).
3. Quality of shade: solid or dappled?
Dappled shade cast by trees with open canopies, such as eucalypts, is often fine for summer-fruiting varieties, although crops are generally not as heavy as they would be in full sun, and extra care must be taken with air circulation and control of fungal diseases. Often, it’s not the shade cast by trees but root competition that is problematic, so place a layer of weed mat under raised beds. Citrus, feijoa, loquat, medlar, quince and currants planted in the ground with year-round dappled shade have been perfectly happy in my garden when they are watered and fertilised generously. In Cinque Terra, with its Mediterranean climate so similar to ours, I spotted many vegetables (zucchini, pumpkins, lettuces, melons) growing in the dappled shade of olive trees.
In heavier shade, I’ve had success with leafy greens like lettuces, silverbeet and spinach, as well as herbs like parsley and, surprisingly, oregano. My currants grew for years in heavy dappled shade before being moved to the new area of the garden, and I now have male and female Tasmanian pepper berries from Peter Taverna thriving in their original spot.
Rhubarb also grows well in a shady spot, and its stems elongate in shade, so that’s a bonus! In the new area, I planted jaboticaba and macadamias in dappled shade, but it’s too early to tell whether they will fruit, although they are growing well.
Trickier is the solid shade to the south of my house. This gets very hot in summer with afternoon sun, but is completely shaded throughout the winter months. I’ve had success with deciduous fruit trees, especially plums – they are slow to get started but, once they achieve some height, receive more sun, too, and they’re dormant during the winter months when the area is permanently shaded.
Despite gummosis in the trunk, my All-in-One almond is fruiting well this year, but it remains to be seen whether the kernels fully ripen. A strawberry guava fruits reliably every year and a pomegranate also fruits, albeit not heavily.
In the new area, a fig in a huge pot to the south of a neighbour’s tall thicket of blackberries currently gets almost no sun. It’s growing slowly but steadily, and in a year or two it will be two metres high and receive sun for many hours each day during its growing season.
Three cloud forest banana passionfruit ( Passiflora tripartite, Passiflora gritensis and Passiflora ‘Mission Dolores’) from plantsman Peter Taverna, are being trained up the southern wall of my shed and receive almost no direct sunlight, other than an hour or two in mid afternoon in midsummer (so far they are thriving, but even this much direct sun may be too much once they grow taller).
4. Manipulating tree canopies
Thinning limbs from mature trees allows more light to reach the ground and, when carefully done, is invisible to all but the trained eye. My local arborist has pruned eucalypts, melaleucas and an oak in this way.
Raising the canopy by cleaning the trunk of tall evergreen trees doesn’t greatly affect shading in summer, when the sun arcs high in the sky, but allows much more sun to reach the ground in winter, when the sun remains low. This is especially useful when growing evergreen fruit trees, such as citrus, under eucalypts.
5. Winter crops vs. summer crops
I’m still trying to succeed with winter crops – I harvest them, but not in winter! Planted in January and February in part sun on my south-facing block, cabbages and caulis grow well until late autumn and then, as the sun dips lower to the north, stop doing much of anything until spring, when they finally form heads. This year, I’m going to push them along with fortnightly Powerfeed and see if that makes a difference.
I haven’t had much luck with onions (brown or white) or shallots, but then they are particularly sensitive to daylight hours and I might have to concede defeat. Still, I can harvest spring onions year-round.
On the other hand, kale, Tuscan black cabbage, bok choy and gai larn (chinese broccoli), silverbeet, perpetual spinach and coriander can all be harvested through winter in my garden, and many of the Tuscan Black cabbage plants even produce for two years before going to seed. In my garden, sprouting broccoli performs somewhere in between kale and caulis – sometimes I can pick stems late in winter, but not reliably. Root crops – parsnips, carrots and beetroot – are fine as long as they’re planted in late summer, rather than autumn. Broad beans grow well too but, again, don’t ripen until mid-late spring.
I’d love to hear from other Hills and cool temperate climate gardeners who have had success with winter vegies in less than full-sun conditions!