The Tropical Fruit Forum

Maybe I can borrow your hawk?  Our hawks don't work at night when the tree rats (Rattus rattus) are at work.  Been fighting the rats for years, won't use poison, so traps on a pole work.  Trap is encircled with hardware cloth with small hole for rat (to keep birds out).  Hook on pole enables placing trap in tree.  Bait is shelled macadamia nut as that is their preference and will ignore other bait. Rats do a job on my macadamias and avocados, but by catching one or two a week I keep the population down.  Surrounding neighbors contribute to the rat population with indifference.  Nearby avocado groves have a serious problem with these introduced rats.
https://animaldiversity.org/accounts/Rattus_rattus/

Been dealing with tree (attic, palm, black) rats, rattus rattus for about 10 years.  Flashing is a good idea, but they readily move from tree to tree throughout the canopy.  Here, their preferred food is macadamia, but also enjoy avocado, apple, etc. They will eat citrus leaving a hollow shell of the fruit.  Nocturnal in nature I cannot easily use my pellet gun.  I do reduce the numbers with metal galvanized rat traps from Amazon (several varieties). I bait the trap with a shelled macadamia nut.  The trap is attached to a 6 ft pole with a hook on the end to hook it in the tree.  The trap, at the upper end is encircled with hardware cloth with an entrance hole for the rat.  Without the hardware cloth I will catch and kill local birds that for some reason need to check out the baited trap, to their misfortune.  I run about 20 traps on our 1 1/2 acre (counting those in our barn) and will get a rat or two each week.  Their carcass is put in the same place on the property each time and after a couple of hours it is gone.  My game camera shows the local crows take the body away (daytime) and raccoons, possums, and local cats work the night.  They are the reason I don't use poison. One night it was a visiting coyote.  Their habits as night feeders preclude our hawks and owls having much effect.  In a month, the macadamias will harden and they can't chew through the shell easily and will welcome my shelled nut attached to the trap and will become food for the others.  Traps must be checked daily or so as the removal of a decomposed rat from a trap is decidedly unpleasant.  I won't "win" this battle as neighbors have the same pests, but I can reduce their numbers and hopefully reduce their reproductive ability.

You might check locally (like CRFG SLO scion exchange in Feb) as so many varieties are available in the Central Coast area due to CRFG members participating in collecting varieties from old-time members who had extensive collections of white sapote.  The Malibu varieties were collected by member John Moore many years ago and are found on local trees (local to Lompoc/Santa Maria).  Nice thing about white sapotes is that they thrive in our area and are very productive.

We have Triumph and Mammoth growing in the Central Coast of CA.  Both are New Zealand varieties and exceed ones like Coolidge, Edenvale, etc. both in flavor and size.  Our climate, however is quite benign.

Interesting discussion.  Alastair, just go for it.  I am in 9b, told I cannot grow macadamias here.  After over 30 years there is a forest of mature macadamias thriving including a variety collection. Frost was originally a problem, but no longer after trees gained some maturity (no more covers, return stack heaters, etc). Macadamias are beasts with regard to poor soil (Protea family, used to poor soil and lack of nutrients).  One can actually easily over fertilize them.  However, our soil is pure dune sand, quickly drains with no nutrients, hard to apply enough water.  I water every other day.  As Kevin said, it is like marbles all over the ground.  Huge crops of nuts, fall on their own.  Different varieties have different flavors.  Most trees were seedlings grafted with selected varieties when they got big enough.  Just plant some seeds (fresh) and see what happens.  Cracking fallen nuts is not a problem, special hand crackers or simply a hammer.  Macadamias are an evergreen tree, tough, beautiful when in bloom. 
An introduced rat is a problem here (and avocado groves, other fruit crops). Rattus rattus (tree rat, palm rat, roof rat) really enjoys the nuts, can chew through husk of immature nuts. Rats are arboreal and nocturnal, move from tree to tree over canopy. Our trees are touching somewhat.  Thankfully there are so many nuts, I am forced to share.  Snap traps on poles hanging in trees (screened to keep birds out) work.  Like dealing with snails (which are eaten by the rats...no more snails!)  Won't use poison as we have other animals that eat caught dead rats (crows, possums, raccoons, other rats). Soon immature nuts will harden their husk and rats won't be able to chew them.  Nuts are the bait, no other bait appeals to them. If you plant some seedlings (fresh nuts), you can see the effect of your growing conditions over time and graft varieties on the seeding as a rootstock (or grow them out...10 years).  Jack, Nipomo

Wish I could give you seeds.  Plant survives, about 4 ft tall, never had flowers or fruit.  Ate the fruit from a tree in Baja, quite good.  Someday....

Might suggest using a yellow sapote (Casimiroa tetrameria) as a dwarfing rootstock.  I have several white sapotes (C. edulis) on their own roots and on white sapote rootstock and they become giant trees producing large quantities of fruit.  They are in the ground on 1 1/2 acres.  I also have several white sapotes (C. edulis) grafted on yellow sapote (C. tetrameria) rootstock that are less than 6 ft tall after 25 years in the ground.  C. tetrameria is a small tree on its own roots and substantially dwarfs C. edulis producing normal sized fruit.  No evidence of any incompatibility.

Several possibilities from earwigs to snail/slugs.  Go out at night with a flashlight and you will probably see the creature(s). 

Couple of comments on rootstock for white sapote Casimiroa edulis...White sapote grafted on yellow sapote Casimiroa tetrameria produces a very small tree (6 ft tall or less).  Yellow sapote grafted on a white sapote rootstock produces a nice sized tree about 6-7 ft tall and spreading.  I have several examples of each, including trees on their own rootstock and their own variety ( C. tetrameria or C. edulis) rootstock.  They are the benefit of playing around with Casimiroa varieties and growing them for 40+ years. Our C. edulis is almost 50 years old, multigrafted, survived 17 degrees, and produces great quantities of fruit (one if which is Vernon, which is also dwarfed on another rootstock-C.tetrameria).  The dwarfed Vernon does not produce the quantity of fruit, of course, but normal sized fruit on a much smaller tree.  Over the years, have not experienced any incompatibility with differing rootstock except for the dwarfing effect. Your results may vary....

Jan Boyce is one of my favorites, but Hellen is even better with flavor and size.

I have several small limbs on multigrafted tree.  No fruit yet.  See Carlos' comment about Russell: https://www.myavocadotrees.com/russell-avocado.html

Have several Capulin cherries growing here for over 20 years.  Beautiful tree, sets lots of fruit not worthy of eating, very much liked by the local birds who plant seeds all over resulting in little seedlings growing here and there.  Grafted a selection years ago on a mature tree that has been removed, fruit not better.  Still worth growing for birds and landscape value. 

My mangos are about 4 years old, size is approx 3 ft.  New growth appearing now (leaves), but probably be joined by flower buds.  With our essentially lack of winter freezing, if the plants would put on stems and leaves instead of flowers, there might be a chance. There might be a method of encouraging growth without flowers and gaining a more sizable tree that could sustain fruit.  These are grafted plants ordered out of Florida.  Might try seedlings to attain vegetative growth initially.