All flowering plants have the same basic needs, though the specifics of those needs--how much or little of something, for instance--varies among the plants. There's a good reason all flowering plants need the same things for life and growth: they're related, all members of a group of plants called angiosperms. Only angiosperms flower.
Flowering plants need light, usually lots of it. Plants convert the energy of light to produce food. The green parts of plants convert the light, the green color due to chlorophyll, which "catches" the energy. Without adequate light, photosynthesis slows or stops, which can prevent flowering plants from producing flowers and fruits.
Photosynthesis also requires carbon dioxide, which plants get from air, taking it in through pores on their leaves called stomata.
Plants also require air for roots. This is why plants that get too much water die. The water fills air spaces between soil grains, preventing roots from absorbing the oxygen contained in that air. Oxygen is one of the important minerals plants need.
Eighteen nutrients supply plants with what they need. Most are absorbed through soil, others through air and water. Plants especially need six of the 18 nutrients. These six are called macronutrients; the other 12 are called micronutrients.
Nitrogen, phosphorus and potassium are macronutrients so important that gardeners often supplement them through fertilizers. On fertilizer packages, the three numbers found separated by hyphens stand for the percentages of nitrogen, phosphorus and potassium found in the package.
Water is crucial to plant survival. Water dissolves the nutrients trapped in soil, which roots then can absorb. Roots pull 98 percent of their nutrients in this way, according to the Arizona Master Gardener Manual. The water then moves up, delivering nutrients to other parts of the plant.
Besides dissolving and delivering nutrients to roots, water, along with carbon dioxide and light, is also necessary for photosynthesis.
Water is also responsible for some of a plant's movement. It exerts pressure and thereby opens and closes stomata and causes roots to move through soil in search of nutrients. It also helps hold a plant upright.
Like all plants, flowering plants need some sort of growing medium in which to sink their roots. Most often this medium is soil, but there are other alternatives--for instance, sand, perlite, vermiculite or moss. Growers should keep in mind that, besides anchoring a plant, soil supplies most of the nutrients plants need. If mediums other than soil are used, nutrients must be supplied by the gardener.
Flowering plants use a lot of energy to flower and fruit. Environmental stresses such as the wrong temperature, harsh winds and too much or too little light can all impede or interrupt the processes that lead to a plant blossoming. It's important for those growing flowers to research the needs of that plant, including appropriate environment. Often, human intervention to protect a plant from temporary problems in the environment--drought, for instance--can be the difference between the plant living or dying.