Do I plant my miniature fruit trees above or below the graft?
I would say just below the graft. It should remain above the soil line.
I have been trying to research online the techniques needed to dwarf a tree and why those steps are necessary. The question I have is: Does the age of the rootstock of a dwarf tree decide how long it will take to produce fruit, or is it the budding scion that decides at what age it will give fruit? For example, if I grow a rootstock from seed that is about 6 months old and graft a scion that has buds (and will produce fruit that year), will the young tree produce fruit, or does it all depend on the age of the rootstock?
I hope this article will be of help to you: https://www.gardeningknowhow.com/ornamental/trees/tgen/grafting-trees-what-is-tree-grafting.htm
Dwarf Fruit Trees – A Planting Guide for Fruit Trees in Containers, can I buy this book?
Sorry, this is not a book but rather one of the articles on the site by Nikki Tiley and is not for sale. You can, however, print it for your use and future reference. Here is the link to the article (print-friendly link at bottom): https://www.gardeningknowhow.com/edible/fruits/fegen/dwarf-fruit-trees-a-planting-guide-for-fruit-trees-in-containers.htm
What size pot do I need to plant dwarf fruit trees in, and how do I plant them? They were a gift to me and I have no gardening experience. Thank you for any help you can give me.
This article will help with growing dwarf fruit trees in containers: https://www.gardeningknowhow.com/edible/fruits/fegen/dwarf-fruit-trees-a-planting-guide-for-fruit-trees-in-containers.htm
I want to plant several varieties of dwarf fruit trees but space in my yard is quite limited. I need to plant 2 varieties of apples and 2 of pears for cross-pollination, and I've been told that the "five in one" and "fruit salad" kind of trees don't really work very well. Can I plant my dwarf trees in pairs, with two trees close together (about 18 or 24 inches apart), then the next pair ten feet away, and a third pair (peach and apricot) ten feet from that?
When planting your trees, consider what the spread of the foliage will be when the tree is mature, and plant far enough apart to allow both trees to spread out. This article provides lots of general inormation: http://extension.unh.edu/resources/files/resource000585_rep607.pdf
For the best trees to plant in your area, consult with your local University of Delaware Extension Service.
I have two miniature limes, two lemons and an orange tree. I get buds on them but they don't produce fruits. What am I doing wrong?
If any were grown from seed, they may not be old enough to bear fruit. They generally 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 Lack of fruiting could also be attributed to poor pollination. 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
What causes this tree to be sticky or sappy? It is about 10 years old and has never done this before. It was in full bloom but now the flowers and the new lemons are falling off. The fruit is turning yellow then drops. Thank you.
It has a pest, most likely scale or aphids. The stickiness is from the honeydew in which these insects secrete. Neem oil will take care of the problem. These articles will help: https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm, https://www.gardeningknowhow.com/plant-problems/pests/homemade-aphid-control-a-natural-way-to-kill-aphids.htm, https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm