How Does Ironite Work With Bottlebrush?

Effects of Iron Deficiency

• Bottlebrush foliage is green from chlorophyll, the same compound it uses to transform sunlight, water, carbon dioxide and soil nutrients into food. In new leaves, iron deficiency depletes the interveinal tissues' chlorophyll. It doesn’t affect older foliage. Severely affected bottlebrushes produce thin shoots with nearly white leaves, while their older twigs lose foliage and die back. Iron also plays roles in the plants' metabolic and respiratory functions.

Ironite Ingredients

• Ironite is a granular fertilizer with a 1-0-1 nitrogen, phosphorous, potassium ratio. This means it’s a phosphorous-free formula containing 1 percent each of nitrogen and potassium. More importantly for your sick bottlebrush, it has 4.5 percent iron and 10 percent sulfur by weight. Ironite -- made of waste tailings from the Arizona Iron King mine -- also contains 5.5 parts per million of arsenic, and trace amounts of other heavy metals.

Is It Safe?

• In response to a lawsuit brought by the Environmental Law Foundation, Ironite’s manufacturer reformulated the product to bring its heavy metal concentrations within California’s legal limits. As of the date of publication, other states monitoring heavy metals in fertilizers are Washington, Oregon and Minnesota. Children are especially sensitive to heavy metal toxicity, so store your Ironite where they won’t accidentally eat it.

The pH Factor

• Bottlebrush shrubs require acidic soil with a pH between 5.6 and 7.5. A higher pH binds the soil’s iron so roots can’t absorb it. If your bottlebrush shows signs of iron deficiency, check its pH with a test kit, available from most garden centers. Amend soil with a pH higher than 7.5 with Ironite. It gives your bottlebrush an immediate boost of soluble iron, while lowering the soil’s pH with sulfur.

Treating Your Bottlebrush

• Treat your bottlebrush with Ironite before new growth begins in late winter or early spring. If its trunk is 2 inches in diameter, space four 4- to 6-inch-deep holes evenly around the drip line, where rain falls from the outermost leaves. Place 8 ounces of Ironite in each hole. If the trunk measures 4 inches, use eight holes containing 12 ounces of Ironite. If the shrub has already lost more than half its leaves from iron deficiency, reduce the Ironite by half. After refilling the holes, water the soil thoroughly. Ironite’s effects gradually wear off, so expect to repeat the application every two to three years.