How does Your Garden Grow?

Louise Grabell

The key to successful gardening lies in how well you take care of your plants. They’ll need your attention when it comes to fertilization. When the question is posed: “How Does Your Garden Grow?” you should have a good answer! My garden grows just fine. The flowers are happy, the citrus trees are green and the tomatoes are delicious. The key is proper fertilization.

Fertilizers come in many varieties and it all can be a bit perplexing. The three main nutrients in a bag of fertilizer are nitrogen, phosphorus and potassium, in that order. A bag of 5–10–5 fertilizer contains 5% useful nitrogen; in a 20-pound bag, that would equal one pound. Ten percent of that same bag would be two pounds of useful phosphorus and, finally one pound (5%) of useful potassium. Add it all up and that’s four pounds out of 20 of useful fertilizer. The rest is the stuff the fertilizer is embedded in which is called filler. Any bag of fertilizer that has a “0” in place of one of the three numbers already mentioned is missing that particular nutrient. So, a bag of 20–0–20 is missing phosphorus as a nutrient. I’ve done my share of Googling to find the correct proportions of each nutrient for the different kinds of plants I have, but I have just used what is available locally and all seems to be fine in my Garden of Eden. This means that your trees, shrubs, flowers and tomatoes will do well with fertilizers labeled for citrus, palm, roses and veggies. Don’t drive yourself crazy—just drive yourself to the garden center and get some fertilizer! Follow the package directions and all will be green and happy. NOTE: fertilizer lovingly spread around your estate is useless unless you water it into the ground. Roots cannot absorb fertilizer laying on the gravel! If your plants can wait for a rainy day, spread the fertilizer the day before and let Mother Nature do the rest!

Nitrogen, phosphorus and potassium are called macronutrients; they are the “big three” needed by all plants. However, there are also micronutrients essential for healthy plant growth like iron, zinc, magnesium, etc. So make sure that you always purchase a “complete” fertilizer. This will contain the “big three” along with many micronutrients all listed on the bags contents. Iron is one of those nutrients that you may have to apply separately in greater quantity. A sure sign of iron deficiency is yellowing new growth with green veins. This is called chlorosis and is a common problem for citrus and photinia. Finally, trees and shrubs that produce pods (mesquite, cassia, cat claw, Mexican bird of paradise, etc.) do not require regular fertilization as they are legumes. Google it!

Master Gardeners invite you to visit their website for up-to-date information and events for your community. Garden questions? You can reach our very own Garden Helpline by calling Pat at 520-407-6459.

Remember, nothing brings more tranquility to the heart than a beautiful garden.