I want to plant m26 rootstock maus gala apple tree.drain is 500mm away horizontally and is 850mm deep. Will this be ok or could roots damage the plastic pipe
Though apple roots are not invasive, they will likely damage plastic. You could opt for a container grown specimen, though! Fortunately, this rootstock does very well in container.
https://www.gardeningknowhow.com/edible/fruits/apples/container-grown-apple-trees.htm
Trees are 3 years old
It could be too much nitrogen or not enough light. Are they under an overhang or getting full sun? They also need the proper pH for the type of apple you are growing. And some varieties take years to mature. Here are general growing tips that should help. We should have an article on the type of apple you have. Just search http://www.gardeningknowhow.com for your apple variety.
https://www.gardeningknowhow.com/edible/fruits/apples/chill-hours-for-apple-trees.htm
https://www.gardeningknowhow.com/edible/fruits/apples/apple-tree-feeding.htm
https://www.gardeningknowhow.com/edible/fruits/apples/pruning-apple-trees.htm
https://www.gardeningknowhow.com/edible/fruits/apples/no-fruit-on-apple-trees.htm
My apple tree, whilst it produces blossom and apples, has wilted leaves covered in a mouldy dust, the branches also appear to have green marks on. Please can you advise what this is and how to treat it ?
Likely, this is Powdery Mildew. Likely, because of the humidity and wet soils in your area. This is, easily, controlled with fungicides of your choice.
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/edible/fruits/apples/controlling-apple-powdery-mildew.htm
This collection of articles will help you to grow apples, successfully:
I am looking to plant either 2 apple trees or one apple and one peach tree. How far apart should they be planted?
This article should help:
https://www.gardeningknowhow.com/edible/fruits/fegen/fruit-tree-spacing-in-gardens.htm
Also, when you purchase the trees, the tags will show the width of the tree at maturity, so be sure to space that far and allow some room between so the branches don't touch.
I purchased a 5 in 1 apple tree and planted in an area that receives 6+ hours of sun in my front yard. However, a gardener friend told me that the tree really should be espaliered along a trellis or fence in order to produce fruit. Basically, my question is - if I leave it where it is will it still fruit?
You can certainly espalier it if you have limited space or want to give it a different kind of support, but it does not require that to bear fruit.
Here's an interesting article:
https://www.gardeningknowhow.com/garden-how-to/propagation/grafting/rootstock-information.htm
For the last couple of years my Gala Apple trees (dwarf) produced every other year. Now for some reason 1 produced in 2021 and the other in 2022. How can I get them back in sync so they both produce in the same year>
Ultimately, this is going to come down to pruning, and thinning fruit at the proper time, and proper fertilization routines.
Some cultivars are more prone to this than others, but thinning the apple crop on overproductive years will keep this from happening as badly.
https://www.gardeningknowhow.com/edible/fruits/fegen/biennial-bearing-information.htm
, the only apples coming out are on the very bottom branches. Is this because the water table is low, or ?
It sounds like it is close to the end of its productive life cycle. At the very least, the tree can be productive for around 25 years. Under ideal conditions, the tree can be productive for 30 or 40 years!
I would make sure to care for it as it should be until it stops producing, or falls apart. See it out with grace!
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm