Growing Citrus in a Cool Temperate Climate
What I’ve learnt during my transition from warm temperate to cool temperate citrus growing
Some Kyneton locals believe that growing citrus in the cool temperate climate here is next to impossible. But I have many citrus trees that thrive and produce an abundance of fruit. Here’s what I know about growing citrus in cool climates. Warm temperate growers, you can use the same principles I’ve outlined in this post to keep your citrus happy and healthy too.
Citrus such as lemons and oranges are great backyard orchard trees. For some folks the quintessential lemon tree is a sentimental inclusion, because “Dad always had a lemon tree”. On quite a few occasions I’ve been called in to collect scions from a very old tree in the backyard of the family home, just before it changes hands. I can then graft that piece of branch onto a new tree, so that the family can continue the legacy in their new home. For some gardeners, citrus provide a cultural connection to a previous homeland, far away from here. The humble lemon tree is an essential backyard (or front yard) inclusion for some Melbourne households who don’t grow any other food.
Toto, I have a feeling we’re not in Kansas anymore
Citrus originated in Asia. The current thinking is that they evolved and radiated out from the foothills of the Himalayas. Over millions of years, citrus first spread naturally and more recently have been spread by humans so they now occur over much of Asia. Even Australia can claim some of its own citrus, with finger limes and other native citrus.
The naturally occurring range for citrus is mostly the sub-tropical regions. Citrus can be temperamental when grown outside a sub-tropical climate, but they can be placated and coaxed into good productivity in warm temperate climates, such as Melbourne’s.
Citrus have particular growth patterns in sub-tropical regions such as Southeast Asia. These patterns are different from those in major citrus producing areas, such as, say, Queensland, which is different again from Mildura’s. Citrus grows differently again in Melbourne, where I have plenty of experience growing oranges, lemons, limes, mandarins and other citrus. Warm-temperate climates are not an ideal place to grow citrus, but you can still get them thriving. When my family lived in Melbourne I put together a five-part series on growing citrus for warm-temperate gardeners (start at part one here).
But what about cool temperate climates, like where I’ve moved to, in Kyneton? Our frosts can be brutal and our summers hot and dry. Kyneton isn’t exactly sub-tropical. But just like Christmas tomatoes and avocados you can indeed grow citrus in a cool temperate climate, like mine.
Citrus are fickle trees
They are easily stressed. They hate it
too hot
too cold
too dry
too wet
without enough soil nutrients
with too much soil nutrient.
And, like me, they utterly despise the wind.
A stressed citrus tree is not a productive tree. In fact, it’s a downright miserable tree. A stressed citrus tree will usually loose its blossoms, its immature fruit and especially its leaves. In a temperate climate (warm or cool), a citrus tree will usually take just over 12 months from flowering to ripen the fruit. If you stress the tree at any point (and don’t manage to kill it), you’ll often lose an entire year’s crop. That means no citrus for a whole year.
There’s a big difference, climate-wise, between Southeast Asia and cool temperate Kyneton. Relative to the sub-tropics, our winters and summers are quite extreme and have the potential to cause stress to a citrus tree. Any attempts to grow citrus will need to take this into account.
The devil is in the detail
Heading to your local nursery in winter, buying a random lemon tree and then plonking it into the ground in the middle of an open paddock is the quickest way to waste your precious time and money. Don’t bother. If you want to grow citrus in a cool temperate climate you’re going to need to think things through and potentially mollycoddle them a bit. Here are some important areas in which to focus your mollycoddling.