Earlier today, some further thoughts on climate change and gardening in summer in New Zealand came to me. As ideas come to me, I would like to continue my thread on this subject. So far, I have written the following posts on the subject of climate change and gardening in New Zealand, which you can read by following the links. If you live overseas and your summers are short with cool temperatures, you may find this information helpful, too.
Before I share some further tips, I just wanted to make the point that I don’t think that we can assume that next summer will be like this year. After all, in recent years we have had droughts that were so severe that the council imposed watering restrictions and a hose ban. The amount of rain we have had this summer in Auckland is not normal. It is usually very dry and we are lucky if it rains at all. But over the past five years or so, in our garden at least, I have noticed a trend towards summer starting later, temperatures being cooler and the summer season is shorter. It is very hard to predict the future unless you have a crystal ball. That’s why I think a middle ground approach might be prudent, which I have set out below.
Taking a middle ground approach
As I have mentioned before, In our garden, we had a lot of failures over summer, which included melons (which did not grow at all), cucumbers (there was perhaps too much rain), large tomatoes (they take a long time to ripen and there wasn’t a lot of sun) and exotic veggies such as snake beans, Malabar spinach, okra, chillies and eggplants (temperatures were not warm enough for them to grow and thrive). Some things did well though, including zucchini, dwarf beans and cherry tomatoes. When sowing seeds and purchasing plants in spring later this year, it is a good idea to plant a bit of everything just to be on the safe side. You never know, there might be a heat wave next year given how unpredictable the weather has been lately. That way, you won’t have wasted too much money and space in the garden. I was in this situation and so too were a lot of other gardeners, but that is only because we got used to a certain pattern in the climate and felt confident that we could grow certain things successfully as we had done in the past. Gone are those days, so perhaps we need to tentatively test the waters next summer.
Grow brassicas in summer
I would never normally consider growing brassicas such as cabbage, cauliflower and broccoli in summer because they tend to fare better in cooler conditions and the dreaded white butterfly is a problem when it’s warm. But if future summers are going to be anything like the one we had in Auckland this year, it may be worth considering instead of planting exotic veggies such as snake beans, okra, superhot chillies and eggplant, which need very hot temperatures in order to grow and crop successfully. There are even some brassica seed varieties that are suitable for growing in summer, such as Sprouting Summer Purple Broccoli and Summer Green Broccoli, both of which are available from Kings Seeds. There is also the Cauliflower All the Year Round, also available from Kings Seeds.
To protect plants from the white butterfly, you can use a powder called derris dust. It is available as organic if you prefer to garden that way. If you don’t want to use any pesticides in your garden, you can always plant your seedlings in rows with tunnel hoops at the end and drape fine netting over. I have done this in the past with kale seedlings planted out in early autumn, when it was still warm. I used some old net curtain fabric and it was successful in preventing the white butterfly from laying eggs which turn into caterpillars which munch holes in the plants.
Grow potatoes instead of kumara
Kumara (sweet potato) needs a very long hot growing season in order to crop successfully. Because summer seems to start later every year, this delays when you can plant out slips (the name for kumara seedlings), meaning that they won’t have as long a time in the ground to grow and develop. You could consider growing potatoes instead of kumara as they don’t usually need as long a growing season in order to mature. They also don’t need as warm temperatures in order to crop well. I recommend planting seed potatoes in October and early November at the latest, while there is still usually rain and the soil is cool, which helps the plants to develop. If you leave it too late, it becomes too hot and dry and the plants won’t develop and form tubers.
If there’s one thing that fared very successfully in the garden during our challenging summer, it is rhubarb. Last year, I planted some seedlings that I grew from seed and the plants are absolutely enormous now, despite very heavy rain and cyclones over the summer. Don’t forget that the leaves are poisonous, so don’t eat them. Rhubarb is very versatile. We enjoy having it stewed with a bit of artificial sweetener over yoghurt. You can also use rhubarb in baking. Rhubarb crumble is a favourite for many people.
Below is a photo of one of our rhubarb plants. I trimmed the leaves because they were so enormous and were hanging over the area where I intend to plant some flower seedlings tomorrow.