Kiwifruit…in Dunedin!?

About five or six years ago I planted what was sold to me as a male and a female (Hayward) kiwi potted together. Over the years I have trained them overhead roughly 10 m along a north facing wall painted white.

The previous three seasons both vines flowered well but no fruit ever set. During each flowering period the weather was fine and many bees were seen foraging in the blossom. I learned that kiwifruit are often incompletely pollinated by bees (wind is also a vector). In 2016 one fruit happened…

It was delicious, but frustrating that mostly it wasn’t working. It took me a while to figure it out…

The one vine the fruit was connected to had to be female. If the other vine was male, surely there would be more than one fruit. But if it was another female, how could there be fruit at all? I’m pretty sure there are no other kiwifruit in my neighbourhood that could have done the job. Nearby in the garden I have Actinidia arguta (hardy/cocktail kiwi) and the male can pollinize the Actinidia deliciosa (regular/fuzzy kiwi). The flowering periods of the two species only just overlap, with the arguta flowering earlier, which I thought could account for the single fruit.

I figured I had two female deliciosa kiwi vines. I learned kiwifruit growers often purchase pollen to ensure good coverage and fruit size, so I bought a few grams and froze it until flowering. I used a small, fine paintbrush to distribute the pollen three times throughout the peak five days of the flowering period. Only a few days later it became apparent it had worked. It is now 22 January, they look strong and both vines are covered in fruit.

Unless I plant a male I’ll need to purchase pollen every year, but it turns out this could be the best option. Kiwi plants are extremely vigorous, especially the males. For a male to be an effective pollinizer it would need to take up at least a few metres of prime growing space and require lots of summer pruning to reduce vigour. I paid $25 for the pollen, so why not use the space the male would have taken up to expand the female and grow at least $25 worth of kiwifruit instead? There is a bit of work (one hour over three days) in painting the pollen but given what I learned about bees, the wind and fruit size I’d probably use a paintbrush anyway between the male and female. As long as I can buy pollen I’m happy. It seems a pretty good option if you are short on space.

I’m glad to have the confusion cleared up – it was disappointing having one of the prime spots in the garden producing only beautiful leaves. This year’s success has encouraged me to make room for the vines to spread out a bit. I had to sacrifice a Tagan feijoa or two, but no worries cause they paid for themselves over and over and things were getting crowded anyway. I have planted new feijoa varieties elsewhere in the garden as a trial and replacement.

Microclimate notes: Kiwis are planted on a wall slightly east of north facing (they miss out on lots of hot late afternoon summer sun but get all of it in spring and autumn. Possibly north-west facing would be best. The wall above and behind the vines is painted white for increased light reflection. The white wall above is kept clear of all vegetation to maintain a large reflective surface (also important for the rest of the lower garden which receives no direct sun for a large chunk of the year). It also makes sense to keep the vines lower for ease of access and to keep them out of the wind. The wall provides near total protection from the coldest southerly winds – this is probably the most important consideration. Other walls and trees provide protection from cooling and drying winds from other directions. The plants are hardy to about minus 12 c, so they won’t die in most coastal Otago gardens, but give them a really sheltered spot so temperatures are elevated during the growing season. The building the vines are attached to is a multi unit housing complex – presumably the residents heat their cold concrete block home and some of that heat escapes to mitigate the cold (probably most relevant through autumn). The best flowering occurred from the 29th of November to the 3rd of December so frost is unlikely to bother the blossom.

Dunedin has so many cozy spots where this could happen. I have eaten small kiwifruit from Ravensbourne! I know of successfully fruiting vines in Carey’s Bay and Port Chalmers. Comment below if you’ve seen any fruit nearby, or have anything to add.