MORE BEAUT BACKYARD FRUIT TREES
STONE AND POME FRUITS FOR TEMPERATE REGIONS
LAST week’s re-published article highlighted a few backyard fruit trees that would be suitable for growing in our region, or indeed, any cool to warm temperate region in Australia (with the humble strawberry making a cameo appearance!).
This week we’ll concentrate on compiling a list of low and medium-chill varieties of stone and pome fruits for cool to warm temperate regions.
Before we start listing varieties, it’s worth looking at how the terms “low”, “medium” and “high-chill” are determined. (There are many methods, but we’ll pick the easiest!)
Firstly, a high-chill area receives anywhere over 650 chill units in a “typical” winter season (Jun-Aug), a medium-chill area receives 450-650 chill units, and a low-chill area receives anywhere under 450 chill units.
A great way to calculate your average chill units is to look up the climate data for your coldest month, usually July, at your location (via BOM website) and calculate your average temperature by adding your mean high and low temperatures and dividing by 2.
This average temperature then relates directly with your winter chill units (there are many Australian internet sites that have this information).
I’ve worked out the chill units for Toowoomba, Warwick, Oakey, Pittsworth and Stanthorpe for a comparison. They are:
1. Toowoomba: Av temp 12.3°C ...Chill units 630 (Medium-chill)
2. Warwick: Av temp 10.6°C. Chill units 720 (High-chill)
3. Oakey: Av temp 10.7°C ...... Chill units 710 (High-chill)
4. Pittsworth: Av temp 10.6°C ..... Chill units 720 (High-chill)
5. Stanthorpe: Av temp 8.0°C ..... Chill units 1100 (High-chill)
Incidentally, in a low-chill area only attempt to grow low-chill varieties, in a medium-chill area you can grow medium and low-chill varieties (protect the low-chill varieties from late frosts), and in a high-chill area you can grow high, medium and low-chill varieties (of course, protecting the medium and low-chill varieties from late frosts).
Now – let’s look at some low to medium-chill varieties.
Last week’s article covered apples pretty conclusively, so let’s plunge headlong into apricots (Prunus armeniaca).
The best low-chill apricots for our region are ‘Bentley’ (early fruiting, matures Nov), ‘Castlebrite’ (early maturity, good size fruit), ‘Divinity’ (early, med-lge fruit), ‘Glengarry’ (early, matures Nov), Newcastle (med sized yellow fleshed fruit, matures late Nov), and ‘Oullins Early’ (early maturity, med-lge fruit). Most apricot varieties are self-pollinating (they may not need a second variety nearby to set fruit) but frosts could reduce fruit set if it damages the early flowering trees.
Most cherry (Prunus avium) varieties need high-chill to set fruit, so they do well around the Granite Belt, Canberra, Tasmania and many areas of Victoria.
This reduces the choice in our temperate region to virtually one variety, ‘Country Red’, a self-pollinating tree bearing quality dark red fruit. Cherries don’t like growing in heavy clay soils and wet summers may cause fruit to split.
One of my favourite stone fruits, currently at its peak in local fruit shops, is the nectarine (Prunus persica var. nectarina).
Most nectarines mature from December through to April. Low-chill varieties to look for are ‘Early Goldmine’ (one of the sweetest nectarines, white flesh, early maturity), ‘Sundowner’ (sweet, yellow flesh, early maturity), ‘Sunraycer’, ‘Sunred’ and ‘Sunwright’ (all early maturity, yellow flesh), and ‘White Delight’ and ‘White Satin’ (white flesh, early maturity).
Like apricots, cherries and peaches, nectarines are self-pollinating and can produce heavy crops if conditions suit.
As they are simply a “fuzz-less peach”, they are susceptible to peach leaf curl, so spraying with a copper-based fungicide at bud swell, autumn leaf drop, and in mid-winter is essential.
“Fuzzy nectarines”, or peaches (Prunus persica), need identical growing conditions to their smooth-skinned relatives.
Full sun and a well-drained soil are essential for most peach trees. Great low-chill peaches to check out are ‘Desert Red’ (yellow flesh, matures Nov), ‘Flordagem’, ‘Florda Gold’, ‘Florda Prince’, and ‘Florda King’ (yellow flesh, matures early Nov), ‘Tropic Beauty’ (yellow flesh, v. low chill, early maturity) and ‘White Velvet’ (white flesh, good flavour, early maturity).
Follow the same spraying regime for peach leaf curl as listed earlier for nectarines. Peaches are one of the most vigorous-growing of the stone fruits, so regular pruning will keep the fruit at a reachable height.
Pears (Pyrus communis) are actually related to apples (pome fruit).
They’ll handle heavier soils and wetter conditions better than stone fruits. Most low-chill pears are self-fertile, but it’s best to check with your attending horticulturist when purchasing, however planting two or more trees will ensure good fruit production.
For our region, try ‘Bonza’ (self-fertile), ‘Clapps Favourite’ (partly self-fertile, good for home gardens), ‘Golden Globe’ (tropical pear, self-fertile), ‘Myra’ and ‘Sunshine’ (self-fertile). ‘Flordahome’ and ‘Hood’ are two tropical pears that will need each other for pollination.
Now I’m a sucker for a sweet, dark-fleshed plum (Prunus salicina), and at the moment the delicious ‘Queen Garnet’ variety is hitting the fruit stores.
Unfortunately, Plant Breeders’ Rights won’t allow these to be sold to the general public, so we’ll have to look at some old favourite low-chill types instead. Here’s a few – ‘Gulf Gold’, ‘Gulf Beauty’, ‘Gulf Blaze’ and ‘Gulf Ruby’ (self-fertile tropical plums, yellow/orange flesh, red skin), ‘Mariposa’ (blood plum, excellent flavour, needs a pollinator like ‘Satsuma’), ‘Satsuma’ (blood plum, dark red skin, spicy flavour), ‘Santa Rosa’ (v. low-chill, deep purple skin, yellow flesh, self-fertile, good pollinator) and we can’t forget the ‘Sugar Plum’ a very sweet small plum which is best pollinated by the ‘Damson’ variety.
Many of these fruit trees are available on dwarfing rootstock, making them suitable for smaller backyards.
My thanks to Malcolm Sypher from Hirstglen Nursery, for his valuable insight and assistance in selecting low-chill varieties for our region.