Does anyone make a wire net to keep the branches of a weeping cheery tree weeping? If so, where would I get one?
You shouldn't need to do this, as the "weeping" is the normal growth habit of the tree. It could be that your tree is grafted and may be in need of pruning to get it to start 'weeping' downward. This article should help: https://www.gardeningknowhow.com/ornamental/trees/weeping-cherry/pruning-weeping-cherry.htm
Tree has what looks like sap at a point low on the trunk and one higher up. It looks healthy, and is 7 yrs old. Anything to worry about? Any actions to take? Thanks.
Is it soot-like in nature? If so, this is sooty mold fungus, usually brought about by insects, like aphids. you can treat the tree with neem oil, which will take care of whatever pest may be attacking the tree as well as the fungus. Here is more information: https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm
https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm
My tree didn't bloom no flowers this spring and now we're in summer.
How old is the tree - is this a new planting? Did it bloom last year?
Did a cold snap occur after budding? If so, this may have killed the buds resulting in no blooms.
Did you prune when the buds were set?
Other possibilities include lack of pollination or excessive nitrogen in the soil (did you fertilize?)
I have a weeping cherry in a pot that is eventually going to be transplanted into the ground. The question is, should I plant it in the ground over winter and dig it up later or bring it inside for winter?
If you have a the location for it outdoors now, I would plant it now and it should be established by winter (make sure to water well). If the location is not ready, then I would recommend heeling it in outdoors. This article will explain more about heeling in:
https://www.gardeningknowhow.com/garden-how-to/info/heeling-in-plants.htm
How do I prune my tree to grow tall instead of short and bushy? It is a grafted tree. It's bushy and only three feet tall. It was planted three years ago. Thanks!
This article will help with maintaining your trees: https://www.gardeningknowhow.com/ornamental/trees/weeping-cherry/pruning-weeping-cherry.htm
I planted a healthy weeping cherry tree in April and did so according to nursery's directions. It's been doing well until three weeks ago when some leaves began curling--sprayed with organic insect killer (for aphids, etc.). Leaves still curled but new leaves are not; now many leaves are turning yellow w/tiny black specks. Please help, as this tree has sentimental meaning. Thank you.
It sounds like the tree has been stressed by lack of water. If it's still in the container, soak it overnight in a tub of water. If it's in the ground, slowly water with 10 gallons of water over a one hour time period. If it is water stress relates, the yellowing and dropping of leaves should lessen.
Since you didn't indicate your USDA hardiness zone, the leaf drop could be nature doing her thing. All cherries in our area (6b) are completely leafless.
https://www.gardeningknowhow.com/ornamental/trees/weeping-cherry/weeping-cherry-growing-tips.htm
Should a 1 year old sapling be streaked to prevent the limbs from dragging or laying on the ground. I have read information on these trees and have found no answers to this particular question!
If the tree is leaning or need support, by all means stake the tree.
Pruning should only be done if it is absolutely necessary.
Here are some links with more information.
https://www.gardeningknowhow.com/ornamental/trees/weeping-cherry/weeping-cherry-growing-tips.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/straighten-tree.htm