This should help.
https://www.gardeningknowhow.com/ornamental/trees/crabapple/flowering-crabapple-trees.htm
https://www.gardeningknowhow.com/ornamental/trees/crabapple/crabapple-feeding-requirements.htm
https://www.gardeningknowhow.com/ornamental/trees/crabapple/do-crabapple-trees-produce-fruit.htm
My tree was here when we moved in 35 years ago. I fertilize with spike fertilizer and this year it has been dropping its leaves and they are spotted. What do I do??
Crabapples can live past 40 years, but then may show decline.
The spots could be apple scab, a fungal disease. It does cause spotting of leaves followed by dropping. The good news is it doesn't usually harm the tree. The best recourse is to rake up the infected leaves and destroy them so as not to spread the disease.
You may want to take some leaves to your local Cooperative Extension Service for a positive identification.
https://www.canr.msu.edu/news/crabapples_can_be_a_star_in_your_landscape
https://www.extension.iastate.edu/news/2007/jul/062704.htm
https://www.gardeningknowhow.com/ornamental/trees/crabapple/flowering-crabapple-trees.htm
Hello! I have a crabapple tree that was sold to me as a Spring Snow fruitless variety. For the last 18 years it has held true to that, and yet, this year, it is producing fruit. I'm wondering if anyone can help me solve this mystery! I'm attaching pictures of the tree. It seems to be a Spring Snow in every way except the new appearance of fruit this year!
It is likely that one or more of the branches originate below a graft point. Those branches will be a different cultivar than the top grafted scion. Otherwise, the cultivar should be, completely, fruitless.
Hello, we have 4 beautiful weeping crabapple trees, that are sending out about as many upright branches as weeping ones. What should we do? I have been cutting off all of the upright ones each year, but the trees are getting taller and that is becoming harder to do. Any suggestions?
You do need to continue to remove any upright branches. Check to make sure nothing is sprouting below the graft union. Those need to come out, too. Sometimes a branch below the graft will go unnoticed and soon it is overtaking the tree, likely with a different specimen.
If you can't reach with a pruning pole, the next option is to hire a professional. Here are pruning tips:
https://www.gardeningknowhow.com/ornamental/trees/crabapple/growing-louisa-crabapple-trees.htm
https://www.gardeningknowhow.com/ornamental/trees/crabapple/crabapple-pruning-info.htm
I have a tree as above, it's been planted over 20 years ago, it is about 16ft high and 12 ft wide and shaped like an upside down mushroom. I have kept it tidy by trimming it bout twice a year but as I am getting older it is more difficult to trim and on one side is a downward bank. Can I cut this back really hard to about 10 ft tall and 8ft wide, it would remove most of the "growing" leafy parts and leave mostly thick branches with twigs coming off them.
Crabapples don't require a lot of pruning. Wait till late winter or early spring to take any off. You can thin it out over several years rather than take a lot off at once. Whatever you do, do not "top it." Here are tips:
https://www.gardeningknowhow.com/ornamental/trees/crabapple/crabapple-pruning-info.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-topping-information.htm
it's an old flowering crab apple I let 4 trunks grow tall I prune any other suckers that come up. this rusty/red/pink colored bumps started last spring & I thought I had pruned them out, but it seems to also be on the trunk. I have decided to cut down the tall shrub, it has gotten too lanky, but I don't know what it is, if it spreads or if the wood needs to be burnt. thank u
As you can see from this article, there isn't anything that exactly matches your description. https://extension.psu.edu/crabapple-diseases Cedar Apple Rust may be the culprit. Here's an article about that: https://www.gardeningknowhow.com/edible/fruits/apples/cedar-apple-rust-control.htm
I would definitely recommend removing and destroying any remaining wood from the tree. You may want to take a close look at any surrounding cedars.
Attaching a picture
Well it could be woodpecker damage or tree borers. Let's hope for woodpeckers.
https://www.gardeningknowhow.com/plant-problems/pests/animals/woodpecker-damage-trees.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-borer-insects.htm
https://www.gardeningknowhow.com/plant-problems/disease/shot-hole-disease-fungus.htm
you should probably contact a certified arborist or at least consult with a local agricultural extension agent. This link might help:
https://www.gardeningknowhow.com/extension-search