Hi. . . . I live in the Mideast and have three citrus trees in my garden (Pomelo, Lemon and Clementine). They were planted 2 years ago and initially bore beautiful fruit. Now 2 years later they still are lush green but show no signs of budding whatsoever. When should I expect them to bud and why do they not seem to show signs of bearing fruit?
If any were grown from seed, they may not be old enough to bear fruit. Most citrus trees need 3-6 years to reach fruit bearing maturity.
Have you fertilized? Nitrogen encourages leaves to grow, but not fruit. Too much can actually keep a plant from producing fruit. This article has information on how to fertilize your trees: https://www.gardeningknowhow.com/edible/fruits/citrus/fertilizing-citrus-trees-best-practices-for-citrus-fertilizing.htm
I would also try giving them some phosphorus rich fertilizer, like bone meal. If the soil is lacking phosphorus, the trees will not be able to produce blossoms (which means no fruit.) In addition, the requirements for lemons are very similar to that of limes. If you have not read it yet, this article may also be helpful: https://www.gardeningknowhow.com/edible/fruits/lime/reasons-and-fixes-for-lime-tree-not-producing-blossoms-or-fruit.htm
After we had the rain, the next day the fruit cracked, split on the tree. I water every other day because we had a very hot summer. The fruit is already very big but it is not ripe till another 3 more months. Thank you.
There can be a few reasons for fruit cracking.
Here is a few links that will help you determine cause and treatment.
What causes the fruit on the tree to have dry juice sacs?
Some varieties of Pomelo are naturally more sour and dry.
Environmental factors can effect the fruit, irregular watering schedule, lack of sun and temperatures all play a part in the fruit.
Correct harvesting schedule. Fruit that is not fully ripe or over ripe may have poor qualities.
Bought a house in Northern California with a very prolific citrus tree. Fruit looks like pomelo on inside but is perfectly round. How do I tell the difference between pomelo and grapefruit trees?
I believe this is a pomelo. Pomelos have a unique leaf shape which can be seen here:
It looks like your tree has these distinctive leaves.
There are several hybrids between pomelo and grapefruit, so this could also be one of those. Unless you're able to get a genetic analysis done, you might not be able to tell specifically if it is one of these.
Does the Pummelo need a male and female tree in order to produce fruit?
No, your tree is self pollinating.
Can pomelo trees be grown in british columbia where summers (40 celcius) are hot but winters are very cold ( as much as minus 30 celcius). Can they grown indoors ?
I fear that those temperatures will be a little too cold. You can grow these indoors, though. You will want to invest in a horticultural light that is rated at 200 watts or greater. This will be a way to get it to fruit indoors. I recommend LED's since they do not consume as much energy.
Here is an article for more information: https://www.gardeningknowhow.com/edible/fruits/pomelos/pomelo-tree-care.htm
This article will give you more information on growing these indoors: https://www.gardeningknowhow.com/edible/fruits/citrus/growing-citrus-trees-indoors.htm
How to grow Penelope fruit
Are you referring to the Pomelo tree? I'm not certain if that's the case or not but here is an article on their care if this is the case:https://www.gardeningknowhow.com/edible/fruits/pomelos/pomelo-tree-care.htm