My daughter dug up some tubers now, so they have foliage but no flowers. They are wilting quicker than I can plant. Should I keep then moist and continue to plant or let them dry out and plant next year?
I would simply allow them to dry out and then replant them later. This article will tell you how to store them for the winter: https://www.gardeningknowhow.com/ornamental/bulbs/calla-lily/calla-lily-winter-care.htm
Additionally, here is an article on caring for the plant that you may find helpful: https://www.gardeningknowhow.com/ornamental/bulbs/calla-lily/growing-calla-lilies-and-care-of-calla-lilies.htm
Once the leaves of the Calla lily have turned brown or yellow, should the plant be cut back?
Yes, once the leaves have turned yellow or brown, you can cut it back.
Can you please tell me if I should cut the stems of the calla lily flower off after it has died?
You can. It will not hurt the plant, but it will not help it either. Pruning the old flowers is done more for aesthetics.
Last summer my calla lilies had plenty of leaves, but sadly no flowers. Could you give advice? Many thanks.
It is either the fertilizer or the sunlight. If you use fertilizer, you may have given them too much nitrogen, which encourages leaves and discourages flowers. If you suspect this may be the case, add phosphorus. Here is more info on phosphorus: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/phosphorus-plant-growth.htm
A lack of sunlight can happen if a nearby plant has grown to shade the area. Check the area and see if the calla lilies are getting enough sun.
Please tell me how to correct this problem. The tips turn brown on both spider plant and calla lily.
I'm assuming these are grown as houseplants. That being said, browning of leaf tips is generally normal and will not harm either plant. This is oftentimes the result of fluoride found in water, which causes salt buildup in the soil. It usually helps to periodically leach plants by giving them a thorough watering to flush out excess salts. Be sure to allow the water to drain out and repeat as needed. It may also help to use distilled water or rainwater when irrigating plants.
My calla lily bulb is very soft in the compost. Should I leave it outside or has it died with the cold?
If the bulb is soft, there is nothing you can do, as it has rotted. Healthy bulbs are firm to the touch. It will need to be replaced.
Mom just received a Calla Lily for Easter. She watered it and the next day there weeping drops of water hanging from the tips of the leaves. Did she over water it?
There may be pests on the plant. They can make the leaves "drip". These articles are on the pests that can cause that:
https://www.gardeningknowhow.com/plant-problems/pests/homemade-aphid-control-a-natural-way-to-kill-aphids.htm
https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm
https://www.gardeningknowhow.com/plant-problems/pests/mealybugs-white-residue-on-plants-leaves.htm