Can I grow a pansy inside the house during the winter months? If so, what do I need to know? Thanking you in advance for your assistance.
You can, but they normally need quite a bit of light in order to do well. Most indoor locations have trouble providing that kind of light. Your best bet is to provide as much light as possible. You will almost certainly need supplemental light from a grow light or a florescent light as well. These supplemental lights will need to be placed very close to the plants in order to be effective.
How can I prevent this from happening and what is the cause? Is it lack of feed?
There are many reasons for yellowing leaves in plants, most of which are stress related. It could also be a nutrient deficiency as you think. This article will help pinpoint the cause for your plant: https://www.gardeningknowhow.com/plant-problems/environmental/plant-leaves-turn-yellow.htm
Will pansies survive 20 degree temps in NE? The local garden center started selling them last weekend when it was 70.
Pansies prefer day temperatures in the 60's and nighttime temperatures 40+. I would wait for the weather to be consistently 45 and above before I would consider planting pansies. Pansies may survive 20 degree temperatures but their foliage probably would suffer (wilt and discolor).
For more information on growing pansies, please visit the following link:
https://www.gardeningknowhow.com/ornamental/flowers/pansy/pansies-care.htm
I have 32 large, robust looking pansy plants that I grew from seeds. There aren't any blooms yet, but there is one with a bud on it. Why? At the greenhouse I see the little trays with small plants already in bloom. Other years I bought pansy plants already blooming, and after I set them out in my flower bed, the leaves turned brown, the plants got tall and leggy and died. There is compost in our soil and it seems like a good mix. What am I doing wrong?
It may be too much nitrogen. Try giving them a little bone meal. This will boost the phosphorous which will help with blooming.
This article will cover some other issues that may cause plants not to bloom:
https://www.gardeningknowhow.com/plant-problems/environmental/plant-not-blooming.htm
Every time I plant pansies, they die ambuscade. They get eaten at the root.
There could be a few reasons for loss of your plants, including rodents, rabbits or other wildlife.
Slugs or snails could also be an issue.
Try planting Pansies in containers.
https://www.gardeningknowhow.com/ornamental/flowers/pansy/pansies-care.htm
Will pansies self start from a pot they were in last spring? - from Iowa
Pansy can self seed, but it is no guarantee that you will have a pot full of flowers this season.
https://www.gardeningknowhow.com/ornamental/flowers/pansy/pansies-care.htm
My pansies keep dying. They turn brown at the base while remaining green at the top. After several days, the plant shrivels up and dies. What is causing this and what can I do to prevent it? I plan on putting petunias in to replace the pansies but will the same thing happen to them? This is the second year this has happened.
There could be a number of reasons why this is happening. Proper environment is important. They like a nutrient rich soil so a layer of organic matter is great. A regular watering schedule is a must. Beyond those reasons your problem could be a disease or fungal. Here is an article on amending soil that may help;
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/improving-garden-soil.htm