I wish to know specifically whether it is possible for garlic bulbs to form in an outdoor DWC setup and if so, what particular considerations should I be mindful of. I do not wish to grow garlic "greens", but fully mature hardneck bulbs. I am growing other veggies successfully in Kratky-inspired buckets and barrels. Has anyone done this successfully with hardneck garlic?
This has been done through many methods. It would seem that they respond well with hydroponics of any form, generally, as long as their pH requirement is met. They must be maintained at a pH of 5.5 to 6.5. Make sure that the roots maintain a high oxygen level, too, since they will be saturated at all times.
Other than that, they respond well, and will respond just fine to your methodology.
Does Neem Oil have any effect on white rot in garlic and other types of onion. If so, when and how to treat for best result?
It would, likely, not have any effect on it at all. Garlic is already full of its own natural fungicide, sulfur, so something a lot less mild like Neem oil will not suffice.
You will probably have to amend with a copper fungicide. This article will help: https://www.gardeningknowhow.com/garden-how-to/info/what-is-copper-fungicide.htm
I planted garlic that I purchased in a local grocery store here in zone 9A and at harvest the bulbs looked and were layered like a golf ball sized onion, but smelled like garlic. I have grown garlic here in years past with normal results. Any ideas?
Your description sounds more like a Shallot.
https://www.gardeningknowhow.com/edible/vegetables/shallot/tips-for-growing-shallots.htm
I have just dug up my elephant garlic. It has tiny bulbils around the bottom. Do I plant them straight back into the soil, or preserve them over winter until next spring?
Garlic prefer a winter planting. As long as it is not hot in your area, then you will be fine to plant at just about any time, but they prefer a cool planting in fall.
These two articles will help: https://www.gardeningknowhow.com/edible/herbs/garlic/grow-elephant-garlic-plants.htm
https://www.gardeningknowhow.com/edible/herbs/garlic/save-garlic-next-year.htm
or should i plant straight away, and would a container be good?
It is best to keep it in dry storage if it is not in soil already.
These two articles will help you: https://www.gardeningknowhow.com/edible/herbs/garlic/grow-elephant-garlic-plants.htm
https://www.gardeningknowhow.com/edible/herbs/garlic/how-to-store-garlic.htm
could it possibly be root rot? what should I do?
Probably. It does appear pretty wet in that spot. They are somewhat drought resistant, but they don't like to have "wet feet" for very long.
You will need to use a fungicide, and let the ground dry out very thoroughly down to AT LEAST 3 inches before watering again.
These articles will help: https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/ornamental/bulbs/society-garlic/growing-society-garlic.htm
I'm a beginner gardener and one of my garlic plants has a bulbil with about 20 pea size bulbils. I live in a zone 3-4 area and have a raised bed. Can I plant them this fall and expect them to grow a garlic bulb next summer? Thanks a bunch!! Ann
You can plant them and they will grow into cloven bulbs but not as quickly as you hoped. Here are the instructions:
https://www.gardeningknowhow.com/edible/herbs/garlic/garlic-plant-bulbils.htm