Others need fiances of another variety nearby for cross pollination. But either way, they still need a hand to move the pollen from the male part of one flower to the female part of another flower, a task undertaken by birds, bees, insects, and wind.
Self-fertile trees include figs, nectarines, quinces, citrus, sour cherries, peaches, persimmons, passionfruit and most berries. Then there are "partially self-fertile" trees that will set fruit on their own but really hanker for a mate. Provide one, and they'll set more fruit.
Fruit trees are fussy about the mating game - much fussier than many humans, I suspect. If a fruit tree needs a pollinating partner it will require a specific variety from the same family to do the job, understandably.
But it has to be a different variety within that family.
Two of the same tree will not cross-pollinate each other.
Not so different from people.
Fortunately, some nurseries sell fruit trees in couples, so you don't have to try to figure out what your apple will be attracted to, and then arrange a relationship. Knowledgeable nurserymen and women will also be able to advise on how best to broker a marriage.
If you're new to orchard trees one of your first choices is probably going to be an apple. Every garden needs an apple tree. It's traditional.
However, many apple trees need a pollinator.
It's best to have two apples (of different varieties) that flower at the same time. You can also use an ornamental crab apple tree as a pollinator (your regular apple won't discriminate against a crab apple). John Downie and Jack Humm make effective pollinators.
If you're going to plant pear trees, be aware that they're choosy about their partners. On top of that, the bees seem not to like them as much as they do apples, so they're further down the list for visiting.
Two well known varieties, William Bon Chretien and Winter Nellis, both need pollinators and, happily, will marry up with one another.
Otherwise, provide Packham's Triumph or Beurre Bosc for your Bon Chretien and Conference for your Winter Nellis.
With the amount of feijoas that friends try to foist off on you during the fruiting season, you'd never think these had any problems when it comes to romance.
But no, they're picky too. Some varieties, such as the popular "Unique" are self-fertile, but most varieties crop better with another feijoa nearby.
Make sure you choose varieties whose flowering times overlap.
You'll need to plan your orchard carefully.
It's very dispiriting to find you've shelled out $25 or $30 a tree and planted them all carefully, only to realise they don't want to have a bar of each other and you've no space left.
Many nurseries specialising in fruit trees have good sites where you can find tables of who likes whom when it comes to pollination.
Check out
www.countrytrading.co.nz
www.wairere.co.nz
www.lushingtons.co.nz
