It's comprised of three main salts which are nitrogen, phosphates and potassium. It is more commonly known as NPK.
Yes, Phostrogen Plant Food can be used on orchid plants, but it should be applied with caution. Orchids generally require a balanced fertilizer with lower nitrogen content, so it's important to dilute the Phostrogen solution according to the package instructions. Additionally, fertilizing should be done during the growing season and less frequently during dormancy to prevent over-fertilization. Always monitor the plant’s response and adjust as necessary.
With proper care Osteospermum will come up every year.Osteospermum should be given a general Phostrogen (Phosphorous/Nitrogen based) fertilizer) to help promote flowering.Osteospermum should also be watered well for the first 2 weeks after planting and then watered regularly to keep the soil from becoming dry. They also prefer sunny locations so be sure to plant them where they'll receive plenty of sunlightHowever, they are not a very hardy plant in colder climates. So it is generally recommended to take cuttings to propagate to ensure that you'll be able to continue to enjoy your Osteospermumevery year.