Well, by the end of July, all my deciduous fruit trees and shrubs are in, including blueberries, currants, jostaberries and bramblefruit. It’s been a mad scramble to finish before budswell… but it’s done! Good soil preparation is vital not least because the new area, unlike my old garden, has never been improved. On the other hand, it’s never been cultivated either; it’s housed horses for many years, and has had plenty of tree cover, so the topsoil is deep and of reasonable quality. And of course, most of the rocks are now in the retaining walls!
Soil pH is a neutral-ish 6 – 6.5 (bottom left on the test plate), with the orange clay subsoil, about 35cm below the surface (top right on the test plate) very acidic at 4.5-5. Other areas, such as the site of the old chicken coop with two decades of composted scraps and wood ash (top left) and the site where much rubbish has been burned (bottom right) are neutral-slightly alkaline.
The pH scale is logarithmic not linear, so 5-6 increases by a factor of ten, 5-7 a factor of 100, 5-8 a factor of 1000 and so on. That’s why it’s easy to change pH one or two points, but difficult for more than that. It’s also why gardeners in areas of the Adelaide Plains with a pH of >8 can only grow blueberries and other acid-lovers in containers. Iron is held more tightly within alkaline soils, so native plants that aren’t adapted to these conditions get lime-induced chlorosis – a yellowing of the leaves caused by a lack of iron. A friend in Seaford had numerous native casualties, but the evidence – subsoil pH 8.5 to 9 – explained the problem!
But happily, no such problem in my garden! That neutral topsoil, plus the terracing which increases soil depth still further, means I can easily raise pH with lime for vegies or trees like persimmon, while keeping it low for acid-lovers like blueberries.
About a week before planting, at least a kilo per square metre of gypsum is forked through every hole and bed and watered in if rain isn’t imminent. Gypsum doesn’t change pH but causes the tiny clay particles to clump together, so the soil becomes better aerated and drained while still retaining the wonderful fertility potential offered by the huge surface area of clay particles.
For deciduous trees, I also add a large bucket of compost from the old garden to the planting area. I also dug through a block of wetted/shredded coir peat to each blueberry planting site. Blueberries prefer very acid soil, so I didn’t plant them in a raised area. Instead, I forked deep and incorporated just a little of the subsoil into the compost and peat. If I had to buy compost, I’d use a commercial mix other than mushroom, because the latter is so alkaline – indeed, I’m amazed that so many Plains gardeners use it.
Bramble fruit are adapted to a deep, composted soil below European deciduous trees, so I dug through two buckets of compost per cane – at least sixteen large buckets in the four or five metre long bed. I was also meticulous about removing perennial weeds. Really I should have waited another year to be sure they were all gone because it’s almost impossible to control weeds in established bramblefruit beds… but I couldn’t resist.
The roots of deciduous fruit trees transplanted from the old garden are a wide, shallow bowl shape whereas new bare-rooted ones are more compact, but planting is the same for both… other than the size of the hole I need to dig! I add NO fertiliser to the hole at planting time as it can burn developing roots; instead I’ll fertilise mid-late August when top growth begins.
After planting, I firm the soil with my boots all around the trunk so the tree is secure, then mulch – usually with pea straw, but pine needles for the blueberries, and oak and elm leaves for bramblefruit.
Only after I’ve mulched do I water, to reduce the chance of soil-borne pathogens splashing onto the trunk or freshly-pruned branches. And then no more water until trees start actively growing and natural rainfall stops, usually in late spring.
Small deciduous trees tend to disappear into the landscape, so I can’t wait to see them all leafy in a month or two! Happy days!