Gardening Tips - General

Not normally a color that you'd expect to find in the garden unless it was fall, or the plant was blooming. Yet, a number of you have been finding it on plants that have no business being yellow right now. What are the causes? Well, there are many. Let's limit ourselves to the highlights.

I have seen plenty of examples of iron chlorosis around. With this problem, all of the leaves have a light green appearance. The telltale indicator is that the veins of the leaf will have a darker green appearance compared to the rest of the leaf. Fertilizing with a high iron fertilizer will fix this problem in the long run.

Fungus is another good cause of yellow leaves. With the high humidities and warm nights of late, this is great fungus growing weather. Usually a fungus infected yellow leaf will have at least one, if not many, black spot on the leaf. The spot is where the fungus spore landed, and the yellow is the progression of the disease. Spraying with a systemic fungicide will prevent the progression of the problem, but not cure it. Infected leaves will stay infected until they fall off (do not use infected leaves for compost!).

Over-watering is quite common. With this problem, the leaves usually will have a hint of black around the edges. The leaves will also usually be more flexible than usual. The cure is self-evident, water only when needed. Check the soil (deeply) before adding water. For more information on correct watering techniques, see Proper Watering Techniques.

Third year needle drop is of note to you evergreen owners. Here, the yellowing is being caused by a lack of sunlight to the oldest of the needles. This is a result of the new growth you've had this year. These yellow needles are getting ready to fall off. There is no course of action here, this is normal. All mature plants are hollow if you part back the growth and take a look inside.

Of course, your problem could be none of these. Even if what you're seeing can be matched by one of the descriptions above, your best plan is to come in and see us. Bring us a sample of the problem in a plastic bag. Multiple leaves are good, attached to the stems, even better. Our staff will have a look at the problem, and send you on your way with the proper solution.