To keep your flowers smelling fresh, it all starts with the base of the flower and the soil.
Plants like flowers and daisies are excellent garden plants to have around the garden because of the natural and lovely fragrances they emit around your home. The first thing you need to do before growing roses and flowers is to make the soil healthy.
There should be a healthy balance of phosphorous, nitrogen and potassium for root, plant and bloom growth.
Bloom growth is the most important factor when it comes to keeping gardens smelling fresh. Having rich soil and rich ingredients will make flowers more potent and stronger when it comes to smell.
Check your local nursery and see what kind it takes to keep flowers smelling fresh and any ingredients needed to keep a healthy garden. Compost and manure are great for supporting soil that has been drained of nutrients. Soil that promotes plant growth is often drained of precious nutrients, and if not replenished it could affect the growth of the plant. Weak soil will not only prevent plants from growing, but plants that are soft will grow into mush if they do not have the proper nutrient balance.
When adding nutrients, you have the best chance of keeping your flowers smelling fresh by using organic compost and soil. Organic soil has the best balance of ingredients when it comes to giving the plants the nutrition they need to thrive. Compost should be composed of natural, plant materials. Make sure any plant refuse is not diseased to prevent the spreading of any fungi or harmful bacterial growth on your plants. Bush clippings, leaves, and stem parts are all great matter for turning into compost. Organic mulch is also a great way to trap moisture and retain heat while roots are growing.
Source of Information on Keeping Flowers Gardens Fresher Longer