The most common daisy is the "Shasta Daisy", Chrysanthemum maximum which is a perennial.
Sometimes, people buy a daisy which are described as Giant Daisy. It is a perennial, but it requires dry conditions in winter, or they may die. Wetness will kill it in the winter, not the cold.
You can plant it in containers, but then they are usually treated as annuals. If you store the container dry and cool for the winter, only watering the container when it is frost free, and the soil is throughly dry, you can overwinter the plants in an unheated garage, tool shed etc. If the planters are large, you can leave them outdoors. Remember to use a good container planting mix which drains well. Avoid clayish garden soil.
Daisies must be deadheaded and like full sun. Fertilize regularily through the summer. Although they like well draining soil, and prefers to stay on the dry side in winter, they should never be allowed to dry out in summer. Water regularily, and deeply, so that the soil is consistently moist. It helps to mulch the plant in summer to preserve moisture.
Gerberas belong to a genus of about 40 species of hairy perennialsfrom grassland in temperate and mountainous regions of Africa, Madagascar, Asia and Indonesia. They are half hardy to frost tender. The ones we mostly know are Gerbera jamesonii ,Barberton Daisy/Transvaal Daisy. Within this ‘group’ there are various cultivars e.g.
Californian Giants’ which have single flowers in shades of yellow, apricot, orange, red, pink and the ‘Pandora’ series to name but two. These are the ones you find either as a cut flower or pot plant with their vibrant colours. They are a beautiful flower but have got a mind of their own when used in arrangements, where they tend to bend and twist, adding their own special magic to your display.
Gerbera, comes in a single stem, with no leaves and comes in wonderful colours from white, yellow, orange, red, through to shocking pink and magenta. They are a lovely vibrant flower which look stunning on their own in a vase with maybe a little bear grass. I would imagine that any florist relay organisation such as Interflora would be able to source these for you. I would be very surprised if they didn’t.
Did you transplant them to a different container after you brought them home? If so, they are probably exhibiting signs of transplant shock which is very understandable with the huge blooms of a Gerbera Daisy. You should probably go ahead and cut off the oldest blooms so that the plant can start producing new blooms. Gerbera Daisies have such large brilliant colored flowers that it takes a little time to produce more.You can tell which are the oldest blooms just by noting the ones that are drooping the worst and the color of the bloom is usually a more faded shade of color than the newer ones.
Since you already used a fertilizer,wait a bit after cutting the old blooms, about one week Then get some Miracle Gro Bloom Buster, or any brand is fine as long as it is for blooms only. Annuals need a boost every now and then throughout the growing season. Mostly they just need a bit of patience and if you ignore them for awhile, they will usually surprise you and perk right up without any help at all.
But especially the Gerbera Daisy will have to be "deadheaded", old blooms removed, every now and then to produce maximum blooms. If you do experience weird weather changes, which is common in spring, and the temperature dips below 40 degrees, bring them in or cover them up.
Several weeks ago I planted Gerber Daisies in potted planters. They looked great for about a week but now they are drooping and sagging. I water every couple of days, however, they are only getting morning/early afternoon sun on my porch, so the soil doesn’t really dry out that much. I added fertilizer to the potting soil mix when I planted them.
I have had to learn not to buy Gerber Daisies, for the reasons you mentioned. They do not hold up well. The nursery people have figured out how to get them to bloom beautifully in their greenhouses, and they look great in the stores, but when you get them home they fall apart. I understand they do like a somewhat dry soil, but not too dry. Probably shouldn’t have fertilized them, since they probably already had fertilizer in the pot. They need "full" sun. They need some protection from the elements.
As pretty as they are, my recommendation is, pass them by in the store and find something less fussy to deal with. If you don’t have a greenhouse that you can keep to a tempture that most of your plants like then as I have said just pass them right by in the store.