Sex Change on Trees

[Daluke]

If you need both female and male trees to set fruit, what happens if you graft one female trunk and than a male onto the same understock.

Will the trunks take on the sex of the roots? Or does it keep what it started at negating the need to have two trees??

[Keep Calm and Ramify]

If you need both female and male trees to set fruit,

The pollinators will set the fruit. Doubt sexes would change from grafting.
Interested to know which fruit trees you have, are you restricted with space?
Someone who knows more about the "birds & bees" will hopefully advise.

[greg27]

The female grafted branch will retain it's own sex. You can buy fruit trees from commercial nurseries where they've grafted different sexes onto the same rootstock, or even different species, so you get different fruit from the same tree.

I remember back when I was a kid my nonna grafted a peach branch to our apricot tree. The graft took but hardly grew at all; every year it would reliably produce a single large peach.

[TimS]

There's a guy in america i think who puts multi grafted trees into public. 30+ different varieties (i think prunus?) grafted onto the same tree to get different fruits. Each branch is it's own variety, it doesn't change, but with all the pollinators on the same tree they all produce their individual fruits.

[shibui]

Above the graft stays the same as the parent it came from - variety, sex, color, etc. Below the graft stays the same too.
Even though the stock and the scion share sap, nutrients, water and hormones the actual genetic makeup of each section cannot change so each part keeps its own identity.
I regularly graft pollinator varieties into an established or developing fruit tree for those with limited space.

One of the issues with such grafts is controlling 2 different varieties. Usually one grows faster than the other and can take over.
Sometimes the owner forgets which branch is the pollinator and prunes it off.

At one stage there was a thing among apple grafters to try to get 100 apple varieties on a single tree. I've heard that some succeeded but I have never actually seen one.

There are (were?) a couple of small fruit tree suppliers offering 'fruit salad' trees locally with a number of plum and apricot (both are related and compatible) varieties on a single tree. Same can be done with citrus.

[terryb]

One of the issues with such grafts is controlling 2 different varieties. Usually one grows faster than the other and can take over.
Sometimes the owner forgets which branch is the pollinator and prunes it off.

The choice of rootstock also affects flowering time, which may counteract what you are trying to achieve for maximum fruit set. For example almond will flower earlier on almond stock, than if on peach x almond hybrid stock, than if on peach stock.

[Keep Calm and Ramify]

I regularly graft pollinator varieties into an established or developing fruit tree for those with limited space.

So if space was limited, it would make sense to graft a single male trunk onto a multi-branched female tree to achieve maximum fruit / crop yield?
(provided the bee's & insects were plentiful...or maybe a soft bristle paintbrush)

[shibui]

So if space was limited, it would make sense to graft a single male trunk onto a multi-branched female tree to achieve maximum fruit / crop yield?
(provided the bee's & insects were plentiful...or maybe a soft bristle paintbrush)

That's what we've done with cherries. While not actually male and female, yield is better with 2 different varieties so a small branch of the correct pollinator can be grown in somewhere on the tree.

What species are you thinking about that is diecious? (separate male and female plants). Most fruiting trees are monoecious with flowers that have both male and female parts but as already mentioned, often fruit set is far better when there is a different variety to donate pollen - apples, pears, cherries and some plums fall in that category.

[Keep Calm and Ramify]

What species are you thinking about that is diecious? (separate male and female plants).

This was the same question I've asked the original poster - Daluke.

I do have a general interest in learning any tips / techniques for better food production (you never know what the future holds!)
I've heard persimmon will benefit from this type of grafting, so maybe one day...Yum!

[Daluke]

No species in particular - just trying to improve my knowledge of horticulture and biology.

[shibui]

I pruned a pear tree today. A few years ago I grafted some extra varieties on it to try to improve fruit set.
I believe the original tree is Buerre Bosc. I grafted Buerre Hardy, Doyen du Comice, Williams and 20th Century Nashi onto convenient upright shoots.

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Grafting onto small stock or young trees is relatively easy. Grafting onto more established trees requires a number of different things.
Grafts on lower branches grow very slowly or not at all due to hormone suppression and shading from the more vigorous upper branches.
Grafts on more vigorous upper branches grow much better.
Grafts in the interior of a tree may not grow well due to shading from the main canopy.
Grafts at the ends of long branches rarely do well. They heal OK and survive but don't grow much because the tree is not sending growth messages to the ends of longer or lower branches.

Grafting is a great skill to develop. Multi grafting opens up even more possibilities.