Give Princess Flowers An Acidic Boost With The Fertilizer Already In Your Kitchen

Princess flower (Tibouchina urvilleana) is one of those plants that just demands attention with its large, showy purple blooms and soft velvety leaves. Hailing from Brazil, this plant can be grown in USDA hardiness zones 9 through 11. It will add some glorious color to your yard when it blooms continuously from spring through to the fall as a royal flower that hummingbirds will enjoy visiting in your garden. Since it prefers acidic soil, you can give princess flower a boost by using a common fertilizer ingredient you already have in your kitchen: Fresh coffee grounds or ground coffee. Apart from acidifying the soil around your princess flower, they'll also provide a few essential nutrients like nitrogen, phosphorus, potassium, magnesium, and calcium for thriving growth.

Unlike spent coffee grounds, which are close to neutral on the pH scale, freshly ground coffee is quite acidic with a pH range of around 4.85 to 5.10. This high level of acidity will certainly give your princess flower a boost, as it prefers a soil pH of around 5.5 to 6.5. On the other hand, while coffee grounds won't give your plant all the required nutrients, they're very valuable in improving the structure of the soil, and increasing microbial activity. This will help to improve drainage and make it easier for your princess flower to get enough goodness for lush new growth and plenty of stunning blooms. 

The best way to use coffee grounds is to sprinkle them around the base of your princess flower and then gently work them into the soil, taking care not to damage the roots. Make sure that you only spread the grounds in a fairly thin layer so that there's not a heavy concentration of caffeine in one spot. Excessive caffeine has been known to stunt plant growth. In fact, one of the things you should never do with coffee grounds around your garden is sprinkle them anywhere near seedlings because the caffeine could inhibit germination and stunt the growth of your young plants. Plus, if you just want to scatter the ground coffee over the soil without working it in, remember to cover it with a layer of mulch. This will stop it forming a hard crust which will prevent the water from getting down to the plant roots.

Although coffee grounds will assist your princess flower by acidifying and enriching the soil, you'll still need to add some additional fertilizer for your plant to thrive. Select one that's recommended for other acid-loving species, like Holly-tone from Espoma. This should be applied in spring and again in the fall for optimum growth. And, if you love your morning brew and happen to have an abundance of coffee dregs, you'll be pleased to know that you can use coffee grounds to give your tomato plants a boost.